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  • graph_tool源码及其注释

    #! /usr/bin/env python
    # -*- coding: utf-8 -*-
    #
    # graph_tool -- a general graph manipulation python module
    #
    # Copyright (C) 2006-2016 Tiago de Paula Peixoto <tiago@skewed.de>
    #
    # This program is free software: you can redistribute it and/or modify
    # it under the terms of the GNU General Public License as published by
    # the Free Software Foundation, either version 3 of the License, or
    # (at your option) any later version.
    #
    # This program is distributed in the hope that it will be useful,
    # but WITHOUT ANY WARRANTY; without even the implied warranty of
    # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    # GNU General Public License for more details.
    #
    # You should have received a copy of the GNU General Public License
    # along with this program.  If not, see <http://www.gnu.org/licenses/>.
    
    """
    graph_tool - efficient graph analysis and manipulation
    ======================================================
    
    Summary
    -------
    
    .. autosummary::
       :nosignatures:
    
       Graph
       GraphView
       Vertex
       Edge
       PropertyMap
       PropertyArray
       load_graph
       group_vector_property
       ungroup_vector_property
       map_property_values
       infect_vertex_property
       edge_endpoint_property
       incident_edges_op
       perfect_prop_hash
       value_types
       show_config
    
    
    This module provides:
    
       1. A :class:`~graph_tool.Graph` class for graph representation and manipulation
       2. Property maps for Vertex, Edge or Graph.
       3. Fast algorithms implemented in C++.
    
    How to use the documentation
    ----------------------------
    
    Documentation is available in two forms: docstrings provided
    with the code, and the full documentation available in
    `the graph-tool homepage <http://graph-tool.skewed.de>`_.
    
    We recommend exploring the docstrings using `IPython
    <http://ipython.scipy.org>`_, an advanced Python shell with TAB-completion and
    introspection capabilities.
    
    The docstring examples assume that ``graph_tool.all`` has been imported as
    ``gt``::
    
       >>> import graph_tool.all as gt
    
    Code snippets are indicated by three greater-than signs::
    
       >>> x = x + 1
    
    Use the built-in ``help`` function to view a function's docstring::
    
       >>> help(gt.Graph)
    
    Contents
    --------
    """
    
    from __future__ import division, absolute_import, print_function
    import sys
    if sys.version_info < (3,):
        range = xrange
    else:
        unicode = str
    
    __author__ = "Tiago de Paula Peixoto <tiago@skewed.de>"
    __copyright__ = "Copyright 2006-2016 Tiago de Paula Peixoto"
    __license__ = "GPL version 3 or above"
    __URL__ = "http://graph-tool.skewed.de"
    
    # import numpy and scipy before everything to avoid weird segmentation faults
    # depending on the order things are imported.
    
    import numpy
    import numpy.ma
    import scipy
    import scipy.stats
    
    
    from .dl_import import *
    dl_import("from . import libgraph_tool_core as libcore")
    __version__ = libcore.mod_info().version
    
    from . import gt_io  # sets up libcore io routines
    
    import sys
    import os
    import re
    import gzip
    import weakref
    import copy
    import textwrap
    import io
    import collections
    
    if sys.version_info < (3,):
        import StringIO
    
    from .decorators import _wraps, _require, _attrs, _limit_args, _copy_func
    from inspect import ismethod
    
    __all__ = ["Graph", "GraphView", "Vertex", "Edge", "VertexBase", "EdgeBase",
               "Vector_bool", "Vector_int16_t", "Vector_int32_t", "Vector_int64_t",
               "Vector_double", "Vector_long_double", "Vector_string",
               "Vector_size_t", "value_types", "load_graph", "PropertyMap",
               "group_vector_property", "ungroup_vector_property",
               "map_property_values", "infect_vertex_property",
               "edge_endpoint_property", "incident_edges_op", "perfect_prop_hash",
               "seed_rng", "show_config", "PropertyArray", "openmp_enabled",
               "openmp_get_num_threads", "openmp_set_num_threads",
               "openmp_get_schedule", "openmp_set_schedule", "__author__",
               "__copyright__", "__URL__", "__version__"]
    
    # this is rather pointless, but it works around a sphinx bug
    graph_tool = sys.modules[__name__]
    
    ################################################################################
    # Utility functions
    ################################################################################
    
    
    def _prop(t, g, prop):
        """Return either a property map, or an internal property map with a given
        name."""
        if isinstance(prop, (str, unicode)):
            try:
                pmap = g.properties[(t, prop)]
            except KeyError:
                raise KeyError("no internal %s property named: %s" %
                               ("vertex" if t == "v" else 
                                ("edge" if t == "e" else "graph"), prop))
        else:
            pmap = prop
        if pmap is None:
            return libcore.any()
        if t != prop.key_type():
            names = {'e': 'edge', 'v': 'vertex', 'g': 'graph'}
            raise ValueError("Expected '%s' property map, got '%s'" %
                             (names[t], names[prop.key_type()]))
        return pmap._get_any()
    
    
    def _degree(g, name):
        """Retrieve the degree type from string, or returns the corresponding
        property map."""
        deg = name
        if name == "in-degree" or name == "in":
            deg = libcore.Degree.In
        elif name == "out-degree" or name == "out":
            deg = libcore.Degree.Out
        elif name == "total-degree" or name == "total":
            deg = libcore.Degree.Total
        else:
            deg = _prop("v", g, deg)
        return deg
    
    
    def _type_alias(type_name):
        alias = {"int8_t": "bool",
                 "boolean": "bool",
                 "short": "int16_t",
                 "int": "int32_t",
                 "unsigned int": "int32_t",
                 "long": "int64_t",
                 "long long": "int64_t",
                 "unsigned long": "int64_t",
                 "object": "python::object",
                 "float": "double"}
        if type_name in alias:
            return alias[type_name]
        if type_name in value_types():
            return type_name
        ma = re.compile(r"vector<(.*)>").match(type_name)
        if ma:
            t = ma.group(1)
            if t in alias:
                return "vector<%s>" % alias[t]
        raise ValueError("invalid property value type: " + type_name)
    
    
    def _python_type(type_name):
        type_name = _type_alias(type_name)
        if "vector" in type_name:
            ma = re.compile(r"vector<(.*)>").match(type_name)
            t = ma.group(1)
            return list, _python_type(t)
        if "int" in type_name:
            return int
        if type_name == "bool":
            return bool
        if "double" in type_name:
            return float
        if type_name == "string":
            return str
        return object
    
    def _gt_type(obj):
        if isinstance(obj, numpy.dtype):
            t = obj.type
        else:
            t = type(obj)
        if issubclass(t, (numpy.int16, numpy.uint16, numpy.int8, numpy.uint8)):
            return "int16_t"
        if issubclass(t, (int, numpy.int32, numpy.uint32)):
            return "int32_t"
        if issubclass(t, (numpy.longlong, numpy.uint64, numpy.int64)):
            return "int64_t"
        if issubclass(t, (float, numpy.float, numpy.float16, numpy.float32, numpy.float64)):
            return "double"
        if issubclass(t, numpy.float128):
            return "long double"
        if issubclass(t, (str, unicode)):
            return "string"
        if issubclass(t, bool):
            return "bool"
        if issubclass(t, (list, numpy.ndarray)):
            return "vector<%s>" % _gt_type(obj[0])
        return "object"
    
    def _converter(val_type):
        # attempt to convert to a compatible python type. This is useful,
        # for instance, when dealing with numpy types.
        vtype = _python_type(val_type)
        if type(vtype) is tuple:
            def convert(val):
                return [vtype[1](x) for x in val]
        elif vtype is object:
            def convert(val):
                return val
        elif vtype is str:
            return _c_str
        else:
            def convert(val):
                return vtype(val)
        return convert
    
    [docs]
    def show_config():
        """Show ``graph_tool`` build configuration."""
        info = libcore.mod_info()
        print("version:", info.version)
        print("gcc version:", info.gcc_version)
        print("compilation flags:", info.cxxflags)
        print("install prefix:", info.install_prefix)
        print("python dir:", info.python_dir)
        print("graph filtering:", libcore.graph_filtering_enabled())
        print("openmp:", libcore.openmp_enabled())
        print("uname:", " ".join(os.uname()))
    
    
    def terminal_size():
        try:
            import fcntl, termios, struct
            h, w, hp, wp = struct.unpack('HHHH',
                fcntl.ioctl(0, termios.TIOCGWINSZ,
                struct.pack('HHHH', 0, 0, 0, 0)))
        except IOError:
            w, h = 80, 100
        return w, h
    
    try:
        libcore.mod_info("wrong")
    except BaseException as e:
        ArgumentError = type(e)
    
    # Python 2 vs 3 compatibility
    
    if sys.version_info < (3,):
        def _c_str(s):
            if isinstance(s, unicode):
                return s.encode("utf-8")
            return str(s)
        def _str_decode(s):
            return s
    else:
        def _c_str(s):
            return str(s)
        def _str_decode(s):
            if isinstance(s, bytes):
                return s.decode("utf-8")
            return s
    
    def get_bytes_io(buf=None):
        """We want BytesIO for python 3, but StringIO for python 2."""
        if sys.version_info < (3,):
            return StringIO.StringIO(buf)
        else:
            return io.BytesIO(buf)
    
    def conv_pickle_state(state):
        """State keys may be of type `bytes` if python 3 is being used, but state was
        pickled with python 2."""
    
        if sys.version_info >= (3,):
            keys = [k for k in state.keys() if type(k) is bytes]
            for k in keys:
                state[k.decode("utf-8")] = state[k]
                del state[k]
    
    
    ################################################################################
    # Property Maps
    ################################################################################
    
    
    [docs]
    class PropertyArray(numpy.ndarray):
        """This is a :class:`~numpy.ndarray` subclass which keeps a reference of its
        :class:`~graph_tool.PropertyMap` owner, and detects if the underlying data
        has been invalidated.
        """
    
        __array_priority__ = -10
    
        def _get_pmap(self):
            return self._prop_map
    
        def _set_pmap(self, value):
            self._prop_map = value
    
        prop_map = property(_get_pmap, _set_pmap,
                            doc=":class:`~graph_tool.PropertyMap` owner instance.")
    
        def __new__(cls, input_array, prop_map):
            obj = numpy.asarray(input_array).view(cls)
            obj.prop_map = prop_map
    
            # check if data really belongs to property map
            if (prop_map._get_data().__array_interface__['data'][0] !=
                obj._get_base_data()):
                obj.prop_map = None
                # do a copy
                obj = numpy.asarray(obj)
    
            return obj
    
        def _get_base(self):
            base = self
            while base.base is not None:
                base = base.base
            return base
    
        def _get_base_data(self):
            return self._get_base().__array_interface__['data'][0]
    
        def _check_data(self):
            if not hasattr(self, "_prop_map") or self.prop_map is None:
                return
    
            data = self.prop_map._get_data()
    
            if (data is None or
                data.__array_interface__['data'][0] != self._get_base_data()):
                raise ValueError(("The graph correspondig to the underlying" +
                                  " property map %s has changed. The" +
                                  " PropertyArray at 0x%x is no longer valid!") %
                                 (repr(self.prop_map), id(self)))
    
        def __array_finalize__(self, obj):
            if type(obj) is PropertyArray:
                obj._check_data()
    
            if obj is not None:
                # inherit prop_map only if the data is the same
                if (type(obj) is PropertyArray and
                    self._get_base_data() == obj._get_base_data()):
                    self.prop_map = getattr(obj, 'prop_map', None)
                else:
                    self.prop_map = None
            self._check_data()
    
        def __array_prepare__(self, out_arr, context=None):
            self._check_data()
            return numpy.ndarray.__array_prepare__(self, out_arr, context)
    
        def __array_wrap__(self, out_arr, context=None):
            #demote to ndarray
            obj = numpy.ndarray.__array_wrap__(self, out_arr, context)
            return numpy.asarray(obj)
    
        # Overload members and operators to add data checking
    
        def _wrap_method(method):
            method = getattr(numpy.ndarray, method)
    
            def checked_method(self, *args, **kwargs):
                self._check_data()
                return method(self, *args, **kwargs)
    
            if ismethod(method):
                checked_method = _wraps(method)(checked_method)
            checked_method.__doc__ = getattr(method, "__doc__", None)
            return checked_method
    
        for method in ['all', 'any', 'argmax', 'argmin', 'argsort', 'astype',
                       'byteswap', 'choose', 'clip', 'compress', 'conj',
                       'conjugate', 'copy', 'cumprod', 'cumsum', 'diagonal', 'dot',
                       'dump', 'dumps', 'fill', 'flat', 'flatten', 'getfield',
                       'imag', 'item', 'itemset', 'itemsize', 'max', 'mean', 'min',
                       'newbyteorder', 'nonzero', 'prod', 'ptp', 'put', 'ravel',
                       'real', 'repeat', 'reshape', 'resize', 'round',
                       'searchsorted', 'setfield', 'setflags', 'sort', 'squeeze',
                       'std', 'sum', 'swapaxes', 'take', 'tofile', 'tolist',
                       'tostring', 'trace', 'transpose', 'var', 'view',
                       '__getitem__']:
            if hasattr(numpy.ndarray, method):
                locals()[method] = _wrap_method(method)
    
    
    
    [docs]
    class PropertyMap(object):
        """This class provides a mapping from vertices, edges or whole graphs to
        arbitrary properties.
    
        See :ref:`sec_property_maps` for more details.
    
        The possible property value types are listed below.
    
        .. table::
    
            =======================     ======================
             Type name                  Alias
            =======================     ======================
            ``bool``                    ``uint8_t``
            ``int16_t``                 ``short``
            ``int32_t``                 ``int``
            ``int64_t``                 ``long``, ``long long``
            ``double``                  ``float``
            ``long double``
            ``string``
            ``vector<bool>``            ``vector<uint8_t>``
            ``vector<int16_t>``         ``short``
            ``vector<int32_t>``         ``vector<int>``
            ``vector<int64_t>``         ``vector<long>``, ``vector<long long>``
            ``vector<double>``          ``vector<float>``
            ``vector<long double>``
            ``vector<string>``
            ``python::object``          ``object``
            =======================     ======================
        """
        def __init__(self, pmap, g, key_type):
            self.__map = pmap
            self.__g = weakref.ref(g)
            self.__base_g = lambda: None
            try:
                if isinstance(g, GraphView):
                    self.__base_g = weakref.ref(g.base)  # keep reference to the
                                                         # base graph, in case the
                                                         # graph view is deleted.
            except NameError:
                pass  # ignore if GraphView is yet undefined
            self.__key_type = key_type
            self.__convert = _converter(self.value_type())
            self.__register_map()
    
        def _get_any(self):
            t = self.key_type()
            g = self.get_graph()
            if t == "v":
                N = g.num_vertices(True)
            elif t == "e":
                N = g.edge_index_range
            else:
                N = 1
            self.reserve(N)
            return self.__map.get_map()
    
        def __key_trans(self, key):
            if self.key_type() == "g":
                return key._Graph__graph
            else:
                return key
    
        def __key_convert(self, k):
            if self.key_type() == "e":
                try:
                    k = (int(k[0]), int(k[1]))
                except:
                    raise ArgumentError
                key = self.__g().edge(k[0], k[1])
                if key is None:
                    raise ValueError("Nonexistent edge: %s" % str(k))
            elif self.key_type() == "v":
                try:
                    key = int(k)
                except:
                    raise ArgumentError
                key = self.__g().vertex(key)
            return key
    
        def __register_map(self):
            for g in [self.__g(), self.__base_g()]:
                if g is not None:
                    g._Graph__known_properties[id(self)] = weakref.ref(self)
    
        def __unregister_map(self):
            for g in [self.__g(), self.__base_g()]:
                if g is not None and id(self) in g._Graph__known_properties:
                    del g._Graph__known_properties[id(self)]
    
        def __del__(self):
            self.__unregister_map()
    
        def __getitem__(self, k):
            k = self.__key_trans(k)
            try:
                return self.__map[k]
            except ArgumentError:
                try:
                    k = self.__key_convert(k)
                    return self.__map[k]
                except ArgumentError:
                    if self.key_type() == "e":
                        kt = "Edge"
                    elif self.key_type() == "v":
                        kt = "Vertex"
                    else:
                        kt = "Graph"
                    raise ValueError("invalid key '%s' of type '%s', wanted type: %s"
                                     % (str(k), str(type(k)), kt) )
    
        def __setitem__(self, k, v):
            key = self.__key_trans(k)
            try:
                try:
                    self.__map[key] = v
                except TypeError:
                    self.__map[key] = self.__convert(v)
            except ArgumentError:
                try:
                    key = self.__key_convert(key)
                    try:
                        self.__map[key] = v
                    except TypeError:
                        self.__map[key] = self.__convert(v)
                except ArgumentError:
                    if self.key_type() == "e":
                        kt = "Edge"
                    elif self.key_type() == "v":
                        kt = "Vertex"
                    else:
                        kt = "Graph"
                    vt = self.value_type()
                    raise ValueError("invalid key value pair '(%s, %s)' of types "
                                     "'(%s, %s)', wanted types: (%s, %s)" %
                                     (str(k), str(v), str(type(k)),
                                      str(type(v)), kt, vt))
        def __iter__(self):
            g = self.__g()
            if self.key_type() == "g":
                iters = [g]
            elif self.key_type() == "v":
                iters = g.vertices()
            else:
                iters = g.edges()
            for x in iters:
                yield self[x]
    
        def __repr__(self):
            # provide some more useful information
            if self.key_type() == "e":
                k = "Edge"
            elif self.key_type() == "v":
                k = "Vertex"
            else:
                k = "Graph"
            g = self.get_graph()
            if g is None:
                g = "a non-existent graph"
            else:
                g = "Graph 0x%x" % id(g)
            return ("<PropertyMap object with key type '%s' and value type '%s',"
                    + " for %s, at 0x%x>") % (k, self.value_type(), g, id(self))
    
    [docs]
        def copy(self, value_type=None, full=True):
            """Return a copy of the property map. If ``value_type`` is specified, the value
            type is converted to the chosen type. If ``full == False``, in the case
            of filtered graphs only the unmasked values are copied (with the
            remaining ones taking the type-dependent default value).
    
            """
            return self.get_graph().copy_property(self, value_type=value_type,
                                                  full=full)
    
    
        def __copy__(self):
            return self.copy()
    
        def __deepcopy__(self, memo):
            if self.value_type() != "python::object":
                return self.copy()
            else:
                pmap = self.copy()
                g = self.get_graph()
                if self.key_type() == "g":
                    iters = [g]
                elif self.key_type() == "v":
                    iters = g.vertices()
                else:
                    iters = g.edges()
                for v in iters:
                    pmap[v] = copy.deepcopy(self[v], memo)
                return pmap
    
    [docs]
        def get_graph(self):
            """Get the graph class to which the map refers."""
            g = self.__g()
            if g is None:
                g = self.__base_g()
            return g
    
    
    [docs]
        def key_type(self):
            """Return the key type of the map. Either 'g', 'v' or 'e'."""
            return self.__key_type
    
    
    [docs]
        def value_type(self):
            """Return the value type of the map."""
            return self.__map.value_type()
    
    
    [docs]
        def python_value_type(self):
            """Return the python-compatible value type of the map."""
            return _python_type(self.__map.value_type())
    
    
    [docs]
        def get_array(self):
            """Get a :class:`~graph_tool.PropertyArray` with the property values.
    
            .. note::
    
               An array is returned *only if* the value type of the property map is
               a scalar. For vector, string or object types, ``None`` is returned
               instead. For vector and string objects, indirect array access is
               provided via the :func:`~graph_tool.PropertyMap.get_2d_array()` and
               :func:`~graph_tool.PropertyMap.set_2d_array()` member functions.
    
            .. warning::
    
               The returned array does not own the data, which belongs to the
               property map. Therefore, if the graph changes, the array may become
               *invalid* and any operation on it will fail with a
               :class:`ValueError` exception. Do **not** store the array if
               the graph is to be modified; store a **copy** instead.
            """
            a = self._get_data()
            if a is None:
                raise ValueError("Cannot get array for value type: " + self.value_type())
            return PropertyArray(a, prop_map=self)
    
    
        def _get_data(self):
            g = self.get_graph()
            if g is None:
                raise ValueError("Cannot get array for an orphaned property map")
            if self.__key_type == 'v':
                n = g._Graph__graph.get_num_vertices(False)
            elif self.__key_type == 'e':
                n = g.edge_index_range
            else:
                n = 1
            a = self.__map.get_array(n)
            return a
    
        def __set_array(self, v):
            a = self.get_array()
            a[:] = v
    
        a = property(get_array, __set_array,
                     doc=r"""Shortcut to the :meth:`~PropertyMap.get_array` method
                     as an attribute. This makes assignments more convenient, e.g.:
    
                     >>> g = gt.Graph()
                     >>> g.add_vertex(10)
                     <...>
                     >>> prop = g.new_vertex_property("double")
                     >>> prop.a = np.random.random(10)           # Assignment from array
                     """)
    
        def __get_set_f_array(self, v=None, get=True):
            g = self.get_graph()
            if g is None:
                return None
            a = self.get_array()
            filt = [None]
            if self.__key_type == 'v':
                filt = g.get_vertex_filter()
                N = g.num_vertices()
            elif self.__key_type == 'e':
                filt = g.get_edge_filter()
                if g.get_vertex_filter()[0] is not None:
                    filt = (g.new_edge_property("bool"), filt[1])
                    libcore.mark_edges(g._Graph__graph, _prop("e", g, filt[0]))
                    if filt[1]:
                        filt[0].a = numpy.logical_not(filt[0].a)
                elif g.edge_index_range != g.num_edges():
                    filt = (g.new_edge_property("bool"), False)
                    libcore.mark_edges(g._Graph__graph, _prop("e", g, filt[0]))
                if filt[0] is None:
                    N = g.edge_index_range
                else:
                    N = (filt[0].a == (not filt[1])).sum()
            if get:
                if a is None:
                    return a
                if filt[0] is None:
                    return a
                return a[filt[0].a == (not filt[1])][:N]
            else:
                if a is None:
                    return
                if filt[0] is None:
                    try:
                        a[:] = v
                    except ValueError:
                        a[:] = v[:len(a)]
                else:
                    m = filt[0].a == (not filt[1])
                    m *= m.cumsum() <= N
                    try:
                        a[m] = v
                    except ValueError:
                        a[m] = v[:len(m)][m]
    
        fa = property(__get_set_f_array,
                      lambda self, v: self.__get_set_f_array(v, False),
                      doc=r"""The same as the :attr:`~PropertyMap.a` attribute, but
                      instead an *indexed* array is returned, which contains only
                      entries for vertices/edges which are not filtered out. If
                      there are no filters in place, the array is not indexed, and
                      is identical to the :attr:`~PropertyMap.a` attribute.
    
                      Note that because advanced indexing is triggered, a **copy**
                      of the array is returned, not a view, as for the
                      :attr:`~PropertyMap.a` attribute. Nevertheless, the assignment
                      of values to the *whole* array at once works as expected.""")
    
        def __get_set_m_array(self, v=None, get=True):
            g = self.get_graph()
            if g is None:
                return None
            a = self.get_array()
            filt = [None]
            if self.__key_type == 'v':
                filt = g.get_vertex_filter()
            elif self.__key_type == 'e':
                filt = g.get_edge_filter()
                if g.get_vertex_filter()[0] is not None:
                    filt = (g.new_edge_property("bool"), filt[1])
                    libcore.mark_edges(g._Graph__graph, _prop("e", g, filt[0]))
                    if filt[1]:
                        filt[0].a = 1 - filt[0].a
            if filt[0] is None or a is None:
                if get:
                    return a
                else:
                    return
            ma = numpy.ma.array(a, mask=(filt[0].a == False) if not filt[1] else (filt[0].a == True))
            if get:
                return ma
            else:
                ma[:] = v
    
        ma = property(__get_set_m_array,
                      lambda self, v: self.__get_set_m_array(v, False),
                      doc=r"""The same as the :attr:`~PropertyMap.a` attribute, but
                      instead a :class:`~numpy.ma.MaskedArray` object is returned,
                      which contains only entries for vertices/edges which are not
                      filtered out. If there are no filters in place, a regular
                      :class:`~graph_tool.PropertyArray` is returned, which is
                      identical to the :attr:`~PropertyMap.a` attribute.""")
    
    [docs]
        def get_2d_array(self, pos):
            r"""Return a two-dimensional array with a copy of the entries of the
            vector-valued property map. The parameter ``pos`` must be a sequence of
            integers which specifies the indexes of the property values which will
            be used. """
    
            if self.key_type() == "g":
                raise ValueError("Cannot create multidimensional array for graph property maps.")
            if "vector" not in self.value_type() and (len(pos) > 1 or pos[0] != 0):
                raise ValueError("Cannot create array of dimension %d (indexes %s) from non-vector property map of type '%s'." 
                                 % (len(pos), str(pos), self.value_type()))
            if "string" in self.value_type():
                if "vector" in self.value_type():
                    p = ungroup_vector_property(self, pos)
                else:
                    p = [self]
                g = self.get_graph()
                vfilt = g.get_vertex_filter()
                efilt = g.get_edge_filter()
                if vfilt[0] is not None:
                    g = GraphView(g, skip_vfilt=True, skip_efilt=True)
                if self.key_type() == "v":
                    N = g.num_vertices()
                    idx = g.vertex_index
                    filt = vfilt
                else:
                    N = g.edge_index_range
                    idx = g.edge_index
                    filt = efilt
                a = [["" for j in range(N)] for i in range(len(p))]
                if self.key_type() == "v":
                    iters = g.vertices()
                else:
                    iters = g.edges()
                for v in iters:
                    for i in range(len(p)):
                        a[i][idx[v]] = p[i][v]
                if len(a) == 1:
                    a = a[0]
                a = numpy.array(a)
                if vfilt[0] is not None:
                    a = a[filt[0].a[:a.shape[0]] == (not filt[1])]
                return a
    
            try:
                return numpy.array(self.fa)
            except ValueError:
                p = ungroup_vector_property(self, pos)
                return numpy.array([x.fa for x in p])
    
    
    [docs]
        def set_2d_array(self, a, pos=None):
            r"""Set the entries of the vector-valued property map from a
            two-dimensional array ``a``. If given, the parameter ``pos`` must be a
            sequence of integers which specifies the indexes of the property values
            which will be set."""
    
            if self.key_type() == "g":
                raise ValueError("Cannot set multidimensional array for graph property maps.")
            if "vector" not in self.value_type():
                if len(a.shape) != 1:
                    raise ValueError("Cannot set array of shape %s to non-vector property map of type %s" % 
                                     (str(a.shape), self.value_type()))
                if self.value_type() != "string":
                    self.fa = a
                else:
                    g = self.get_graph()
                    if self.key_type() == "v":
                        iters = g.vertices()
                    else:
                        iters = sorted(g.edges(), key=lambda e: g.edge_index[e])
                    for j, v in enumerate(iters):
                        self[v] = a[j]
                return
    
            val = self.value_type()[7:-1]
            ps = []
            for i in range(a.shape[0]):
                ps.append(self.get_graph().new_property(self.key_type(), val))
                if self.value_type() != "string":
                    ps[-1].fa = a[i]
                else:
                    g = self.get_graph()
                    if self.key_type() == "v":
                        iters = g.vertices()
                    else:
                        iters = g.edges()
                    for j, v in enumerate(iters):
                        ps[-1][v] = a[i, j]
            group_vector_property(ps, val, self, pos)
    
    
    [docs]
        def is_writable(self):
            """Return True if the property is writable."""
            return self.__map.is_writable()
    
    
    
    [docs]
        def set_value(self, val):
            """Sets all values in the property map to ``val``."""
            g = self.get_graph()
            if self.key_type() == "v":
                libcore.set_vertex_property(g._Graph__graph, _prop("v", g, self), val)
            elif self.key_type() == "e":
                libcore.set_edge_property(g._Graph__graph, _prop("e", g, self), val)
            else:
                self[g] = val
    
    
    [docs]
        def reserve(self, size):
            """Reserve enough space for ``size`` elements in underlying container. If the
               original size is already equal or larger, nothing will happen."""
            self.__map.reserve(size)
    
    
    [docs]
        def resize(self, size):
            """Resize the underlying container to contain exactly ``size`` elements."""
            self.__map.resize(size)
    
    
    [docs]
        def shrink_to_fit(self):
            """Shrink size of underlying container to accommodate only the necessary amount,
            and thus potentially freeing memory."""
            g = self.get_graph()
            if self.key_type() == "v":
                size = g.num_vertices(True)
            elif self.key_type() == "e":
                size = g.edge_index_range
            else:
                size = 1
            self.__map.resize(size)
            self.__map.shrink_to_fit()
    
    
        def __getstate__(self):
            g = self.get_graph()
            if g is None:
                raise ValueError("cannot pickle orphaned property map")
            value_type = self.value_type()
            key_type = self.key_type()
            if not self.is_writable():
                vals = None
            else:
                u = GraphView(g, skip_vfilt=True, skip_efilt=True)
                if key_type == "v":
                    vals = [self.__convert(self[v]) for v in u.vertices()]
                elif key_type == "e":
                    vals = [self.__convert(self[e]) for e in u.edges()]
                else:
                    vals = self.__convert(self[g])
    
            state = dict(g=g, value_type=value_type,
                         key_type=key_type, vals=vals,
                         is_vindex=self is g.vertex_index,
                         is_eindex=self is g.edge_index)
    
            return state
    
        def __setstate__(self, state):
            conv_pickle_state(state)
            g = state["g"]
            key_type = _str_decode(state["key_type"])
            value_type = _str_decode(state["value_type"])
            vals = state["vals"]
    
            if state["is_vindex"]:
                pmap = g.vertex_index
            elif state["is_eindex"]:
                pmap = g.edge_index
            else:
                u = GraphView(g, skip_vfilt=True, skip_efilt=True)
                if key_type == "v":
                    pmap = u.new_vertex_property(value_type, vals=vals)
                elif key_type == "e":
                    pmap = u.new_edge_property(value_type, vals=vals)
                else:
                    pmap = u.new_graph_property(value_type)
                    pmap[u] = vals
                pmap = g.own_property(pmap)
    
            self.__map = pmap.__map
            self.__g = pmap.__g
            self.__base_g = pmap.__base_g
            self.__key_type = key_type
            self.__convert = _converter(self.value_type())
            self.__register_map()
    
    
    
    def _check_prop_writable(prop, name=None):
        if not prop.is_writable():
            raise ValueError("property map%s is not writable." %
                             ((" '%s'" % name) if name != None else ""))
    
    
    def _check_prop_scalar(prop, name=None, floating=False):
        scalars = ["bool", "int16_t", "int32_t", "int64_t", "unsigned long",
                   "double", "long double"]
        if floating:
            scalars = ["double", "long double"]
    
        if prop.value_type() not in scalars:
            raise ValueError("property map%s is not of scalar%s type." %
                             (((" '%s'" % name) if name != None else ""),
                              (" floating" if floating else "")))
    
    
    def _check_prop_vector(prop, name=None, scalar=True, floating=False):
        scalars = ["bool", "int16_t", "int32_t", "int64_t", "unsigned long",
                   "double", "long double"]
        if not scalar:
            scalars += ["string"]
        if floating:
            scalars = ["double", "long double"]
        vals = ["vector<%s>" % v for v in scalars]
        if prop.value_type() not in vals:
            raise ValueError("property map%s is not of vector%s type." %
                             (((" '%s'" % name) if name != None else ""),
                              (" floating" if floating else "")))
    
    
    [docs]
    def group_vector_property(props, value_type=None, vprop=None, pos=None):
        """Group list of properties ``props`` into a vector property map of the same type.
    
        Parameters
        ----------
        props : list of :class:`~graph_tool.PropertyMap`
            Properties to be grouped.
        value_type : string (optional, default: None)
            If supplied, defines the value type of the grouped property.
        vprop : :class:`~graph_tool.PropertyMap` (optional, default: None)
            If supplied, the properties are grouped into this property map.
        pos : list of ints (optional, default: None)
            If supplied, should contain a list of indexes where each corresponding
            element of ``props`` should be inserted.
    
        Returns
        -------
        vprop : :class:`~graph_tool.PropertyMap`
           A vector property map with the grouped values of each property map in
           ``props``.
    
        Examples
        --------
        >>> from numpy.random import seed, randint
        >>> from numpy import array
        >>> seed(42)
        >>> gt.seed_rng(42)
        >>> g = gt.random_graph(100, lambda: (3, 3))
        >>> props = [g.new_vertex_property("int") for i in range(3)]
        >>> for i in range(3):
        ...    props[i].a = randint(0, 100, g.num_vertices())
        >>> gprop = gt.group_vector_property(props)
        >>> print(gprop[g.vertex(0)].a)
        [51 25  8]
        >>> print(array([p[g.vertex(0)] for p in props]))
        [51 25  8]
        """
        g = props[0].get_graph()
        vtypes = set()
        keys = set()
        for i, p in enumerate(props):
            if "vector" in p.value_type():
                raise ValueError("property map 'props[%d]' is a vector property." %
                                 i)
            vtypes.add(p.value_type())
            keys.add(p.key_type())
        if len(keys) > 1:
            raise ValueError("'props' must be of the same key type.")
        k = keys.pop()
    
        if vprop == None:
            if value_type == None and len(vtypes) == 1:
                value_type = vtypes.pop()
    
            if value_type != None:
                value_type = "vector<%s>" % value_type
                if k == 'v':
                    vprop = g.new_vertex_property(value_type)
                elif k == 'e':
                    vprop = g.new_edge_property(value_type)
                else:
                    vprop = g.new_graph_property(value_type)
            else:
                ValueError("Can't automatically determine property map value" +
                           " type. Please provide the 'value_type' parameter.")
        _check_prop_vector(vprop, name="vprop", scalar=False)
    
        for i, p in enumerate(props):
            if k != "g":
                u = GraphView(g, directed=True, reversed=g.is_reversed(),
                              skip_properties=True)
                libcore.group_vector_property(u._Graph__graph, _prop(k, g, vprop),
                                              _prop(k, g, p),
                                              i if pos == None else pos[i],
                                              k == 'e')
            else:
                vprop[g][i if pos is None else pos[i]] = p[g]
        return vprop
    
    
    
    [docs]
    def ungroup_vector_property(vprop, pos, props=None):
        """Ungroup vector property map ``vprop`` into a list of individual property maps.
    
        Parameters
        ----------
        vprop : :class:`~graph_tool.PropertyMap`
            Vector property map to be ungrouped.
        pos : list of ints
            A list of indexes corresponding to where each element of ``vprop``
            should be inserted into the ungrouped list.
        props : list of :class:`~graph_tool.PropertyMap`  (optional, default: None)
            If supplied, should contain a list of property maps to which ``vprop``
            should be ungroupped.
    
        Returns
        -------
        props : list of :class:`~graph_tool.PropertyMap`
           A list of property maps with the ungrouped values of ``vprop``.
    
        Examples
        --------
        >>> from numpy.random import seed, randint
        >>> from numpy import array
        >>> seed(42)
        >>> gt.seed_rng(42)
        >>> g = gt.random_graph(100, lambda: (3, 3))
        >>> prop = g.new_vertex_property("vector<int>")
        >>> for v in g.vertices():
        ...    prop[v] = randint(0, 100, 3)
        >>> uprops = gt.ungroup_vector_property(prop, [0, 1, 2])
        >>> print(prop[g.vertex(0)].a)
        [51 92 14]
        >>> print(array([p[g.vertex(0)] for p in uprops]))
        [51 92 14]
        """
    
        g = vprop.get_graph()
        _check_prop_vector(vprop, name="vprop", scalar=False)
        k = vprop.key_type()
        value_type = vprop.value_type().split("<")[1].split(">")[0]
        if props == None:
            if k == 'v':
                props = [g.new_vertex_property(value_type) for i in pos]
            elif k == 'e':
                props = [g.new_edge_property(value_type) for i in pos]
            else:
                props = [g.new_graph_property(value_type) for i in pos]
    
        for i, p in enumerate(pos):
            if props[i].key_type() != k:
                raise ValueError("'props' must be of the same key type as 'vprop'.")
    
            if k != 'g':
                u = GraphView(g, directed=True, reversed=g.is_reversed(),
                              skip_properties=True)
                libcore.ungroup_vector_property(u._Graph__graph,
                                                _prop(k, g, vprop),
                                                _prop(k, g, props[i]),
                                                p, k == 'e')
            else:
                if len(vprop[g]) <= pos[i]:
                    vprop[g].resize(pos[i] + 1)
                props[i][g] = vprop[g][pos[i]]
        return props
    
    
    [docs]
    def map_property_values(src_prop, tgt_prop, map_func):
        """Map the values of ``src_prop`` to ``tgt_prop`` according to the mapping
        function ``map_func``.
    
        Parameters
        ----------
        src_prop : :class:`~graph_tool.PropertyMap`
            Source property map.
        tgt_prop : :class:`~graph_tool.PropertyMap`
            Target property map.
        map_func : function or callable object
            Function mapping values of ``src_prop`` to values of ``tgt_prop``.
    
        Returns
        -------
        None
    
        Examples
        --------
        >>> g = gt.collection.data["lesmis"]
        >>> label_len = g.new_vertex_property("int64_t")
        >>> gt.map_property_values(g.vp.label, label_len,
        ...                        lambda x: len(x))
        >>> print(label_len.a)
        [ 6  8 14 11 12  8 12  8  5  6  7  7 10  6  7  7  9  9  7 11  9  6  7  7 13
         10  7  6 12 10  8  8 11  6  5 12  6 10 11  9 12  7  7  6 14  7  9  9  8 12
          6 16 12 11 14  6  9  6  8 10  9  7 10  7  7  4  9 14  9  5 10 12  9  6  6
          6 12]
        """
    
        if src_prop.key_type() != tgt_prop.key_type():
            raise ValueError("src_prop and tgt_prop must be of the same key type")
        g = src_prop.get_graph()
        k = src_prop.key_type()
        if k == "g":
            tgt_prop[g] = map_func(src_prop[g])
            return
        u = GraphView(g, directed=True, reversed=g.is_reversed(),
                      skip_properties=True)
        libcore.property_map_values(u._Graph__graph,
                                    _prop(k, g, src_prop),
                                    _prop(k, g, tgt_prop),
                                    map_func, k == 'e')
    
    
    [docs]
    def infect_vertex_property(g, prop, vals=None):
        """Propagate the `prop` values of vertices with value `val` to all their
        out-neighbours.
    
        Parameters
        ----------
        prop : :class:`~graph_tool.PropertyMap`
            Property map to be modified.
        vals : list (optional, default: `None`)
            List of values to be propagated. If not provided, all values
            will be propagated.
    
        Returns
        -------
        None : ``None``
    
        Examples
        --------
        >>> from numpy.random import seed
        >>> seed(42)
        >>> gt.seed_rng(42)
        >>> g = gt.random_graph(100, lambda: (3, 3))
        >>> prop = g.vertex_index.copy("int32_t")
        >>> gt.infect_vertex_property(g, prop, [10])
        >>> print(sum(prop.a == 10))
        4
        """
        libcore.infect_vertex_property(g._Graph__graph, _prop("v", g, prop),
                                       vals)
    
    
    
    @_limit_args({"endpoint": ["source", "target"]})
    [docs]
    def edge_endpoint_property(g, prop, endpoint, eprop=None):
        """Return an edge property map corresponding to the vertex property `prop` of
        either the target and source of the edge, according to `endpoint`.
    
        Parameters
        ----------
        prop : :class:`~graph_tool.PropertyMap`
            Vertex property map to be used to propagated to the edge.
        endpoint : `"source"` or `"target"`
            Edge endpoint considered. If the graph is undirected, the source is
            always the vertex with the lowest index.
        eprop : :class:`~graph_tool.PropertyMap` (optional, default: `None`)
            If provided, the resulting edge properties will be stored here.
    
        Returns
        -------
        eprop : :class:`~graph_tool.PropertyMap`
            Propagated edge property.
    
        Examples
        --------
        >>> gt.seed_rng(42)
        >>> g = gt.random_graph(100, lambda: (3, 3))
        >>> esource = gt.edge_endpoint_property(g, g.vertex_index, "source")
        >>> print(esource.a)
        [ 0  0  0 96 96 96 92 92 92 88 88 88 84 84 84 80 80 80 76 76 76 72 72 72 68
         68 68 64 64 64 60 60 60 56 56 56 52 52 52 48 48 48 44 44 44 40 40 40 36 36
         36 32 32 32 28 28 28 24 24 24 20 20 20 16 16 16 12 12 12  8  8  8  4  4  4
         99 99 99  1  1  1  2  2  2  3  3  3  5  5  5  6  6  6  7  7  7  9  9  9 10
         10 10 14 14 14 19 19 19 25 25 25 30 30 30 35 35 35 41 41 41 46 46 46 51 51
         51 57 57 57 62 62 62 67 67 67 73 73 73 78 78 78 83 83 83 89 89 89 94 94 94
         11 11 11 98 98 98 97 97 97 95 95 95 93 93 93 91 91 91 90 90 90 87 87 87 86
         86 86 85 85 85 82 82 82 81 81 81 79 79 79 77 77 77 75 75 75 74 74 74 71 71
         71 69 69 69 61 61 61 54 54 54 47 47 47 39 39 39 33 33 33 26 26 26 18 18 18
         70 70 70 13 13 13 15 15 15 17 17 17 21 21 21 22 22 22 23 23 23 27 27 27 29
         29 29 31 31 31 34 34 34 37 37 37 38 38 38 42 42 42 43 43 43 45 45 45 49 49
         49 50 50 50 53 53 53 55 55 55 58 58 58 59 59 59 63 63 63 65 65 65 66 66 66]
        """
    
        val_t = prop.value_type()
        if val_t == "unsigned long" or val_t == "unsigned int":
            val_t = "int64_t"
        if eprop is None:
            eprop = g.new_edge_property(val_t)
        if eprop.value_type() != val_t:
            raise ValueError("'eprop' must be of the same value type as 'prop': " +
                             val_t)
        libcore.edge_endpoint(g._Graph__graph, _prop("v", g, prop),
                              _prop("e", g, eprop), endpoint)
        return eprop
    
    
    @_limit_args({"direction": ["in", "out"], "op": ["sum", "prod", "min", "max"]})
    [docs]
    def incident_edges_op(g, direction, op, eprop, vprop=None):
        """Return a vertex property map corresponding to a specific operation (sum,
        product, min or max) on the edge property `eprop` of incident edges on each
        vertex, following the direction given by `direction`.
    
        Parameters
        ----------
        direction : `"in"` or `"out"`
            Direction of the incident edges.
        op : `"sum"`, `"prod"`, `"min"` or `"max"`
            Operation performed on incident edges.
        eprop : :class:`~graph_tool.PropertyMap`
            Edge property map to be summed.
        vprop : :class:`~graph_tool.PropertyMap` (optional, default: `None`)
            If provided, the resulting vertex properties will be stored here.
    
        Returns
        -------
        vprop : :class:`~graph_tool.PropertyMap`
            Summed vertex property.
    
        Examples
        --------
        >>> gt.seed_rng(42)
        >>> g = gt.random_graph(100, lambda: (3, 3))
        >>> vsum = gt.incident_edges_op(g, "out", "sum", g.edge_index)
        >>> print(vsum.a)
        [  3 237 246 255 219 264 273 282 210 291 300 453 201 687 309 696 192 705
         669 318 183 714 723 732 174 327 660 741 165 750 336 759 156 651 768 345
         147 777 786 642 138 354 795 804 129 813 363 633 120 822 831 372 111 840
         624 849 102 381 858 867  93 615 390 876  84 885 894 399  75 606 678 597
          66 408 588 579  57 570 417 561  48 552 543 426  39 534 525 516  30 435
         507 498  21 489 444 480  12 471 462 228]
    
        """
    
        val_t = eprop.value_type()
        if val_t == "unsigned long" or val_t == "unsigned int":
            val_t = "int64_t"
        if vprop is None:
            vprop = g.new_vertex_property(val_t)
        orig_vprop = vprop
        if vprop.value_type != val_t:
            vprop = g.new_vertex_property(val_t)
        if direction == "in" and not g.is_directed():
            return orig_vprop
        if direction == "in":
            g = GraphView(g, reversed=True, skip_properties=True)
        libcore.out_edges_op(g._Graph__graph, _prop("e", g, eprop),
                              _prop("v", g, vprop), op)
        if vprop is not orig_vprop:
            g.copy_property(vprop, orig_vprop)
        return orig_vprop
    
    
    @_limit_args({"htype": ["int8_t", "int32_t", "int64_t"]})
    [docs]
    def perfect_prop_hash(props, htype="int32_t"):
        """Given a list of property maps `props` of the same type, a derived list of
        property maps with integral type `htype` is returned, where each value is
        replaced by a perfect (i.e. unique) hash value.
    
        .. note::
           The hash value is deterministic, but it will not be necessarily the same
           for different values of `props`.
        """
    
        val_types = set([p.value_type() for p in props])
        if len(val_types) > 1:
            raise ValueError("All properties must have the same value type")
        hprops = [p.get_graph().new_property(p.key_type(), htype) for p in props]
    
        eprops = [p for p in props if p.key_type() == "e"]
        heprops = [p for p in hprops if p.key_type() == "e"]
    
        vprops = [p for p in props if p.key_type() == "v"]
        hvprops = [p for p in hprops if p.key_type() == "v"]
    
        hdict = libcore.any()
    
        for eprop, heprop in zip(eprops, heprops):
            g = eprop.get_graph()
            g = GraphView(g, directed=True, skip_properties=True)
            libcore.perfect_ehash(g._Graph__graph, _prop('e', g, eprop),
                                  _prop('e', g, heprop), hdict)
    
        for vprop, hvprop in zip(vprops, hvprops):
            g = vprop.get_graph()
            g = GraphView(g, directed=True, skip_properties=True)
            libcore.perfect_vhash(g._Graph__graph, _prop('v', g, vprop),
                                  _prop('v', g, hvprop), hdict)
    
        return hprops
    
    
    
    
    class InternalPropertyDict(dict):
        """Internal dictionary of property maps. It only accepts string keys and
        :class:`PropertyMap` instances as values."""
    
        def __init__(self, g):
            self.g = weakref.ref(g)
            dict.__init__(self)
    
        @_require("key", tuple)
        @_require("val", PropertyMap)
        def __setitem__(self, key, val):
            t, k = key
            self.__set_property(t, k, val)
    
        @_limit_args({"t": ["v", "e", "g"]})
        @_require("key", str)
        def __set_property(self, t, key, v):
            dict.__setitem__(self, (t, key), v)
    
        @_require("key", tuple)
        def __delitem__(self, key):
            dict.__delitem__(self, key)
    
        @_require("key", tuple)
        def setdefault(self, key, default=None):
            if not isinstance(default, PropertyMap):
                raise ValueError("default parameter must be of type PropertyMap, not: %s" % type(default))
            v = self.get(key, None)
            if v is None:
                self[key] = v = default
            return v
    
        if sys.version_info < (3,):
            def update(self, *args, **kwargs):
                temp = dict(*args, **kwargs)
                for k, v in temp.iteritems():
                    self[k] = v
        else:
            def update(self, *args, **kwargs):
                temp = dict(*args, **kwargs)
                for k, v in temp.items():
                    self[k] = v
    
    
    class PropertyDict(object):
        """Wrapper for the dict of vertex, graph or edge properties, which sets the
        value on the property map when changed in the dict.
    
        For convenience, the dictionary entries are also available via attributes.
        """
        def __init__(self, properties, t):
            super(PropertyDict, self).__setattr__("properties", properties)
            super(PropertyDict, self).__setattr__("t", t)
    
        def __contains__(self, key):
            return (self.t, key) in self.properties
    
        def __getitem__(self, key):
            if self.t == "g":
                p = self.properties[(self.t, key)]
                return p[p.get_graph()]
            return self.properties[(self.t, key)]
    
        def get(self, key, default=None):
            try:
                return self[key]
            except KeyError:
                return default
    
        def __setitem__(self, key, val):
            k = (self.t, key)
            if self.t == "g" and not isinstance(val, PropertyMap) and k in self.properties:
                p = self.properties[k]
                p[p.get_graph()] = val
            else:
                if not isinstance(val, PropertyMap):
                    raise ValueError("value must be of type PropertyMap, not %s" % str(type(val)))
                if val.key_type() != self.t:
                    def name(t):
                        if t == "e":
                            return "Edge"
                        if t == "v":
                            return "Vertex"
                        if t == "g":
                            return "Graph"
                    raise ValueError("wanted a property map of type '%s', not '%s'" %
                                     (name(self.t), name(val.key_type())))
                self.properties[k] = val
    
        def setdefault(self, key, default=None):
            self.properties.setdefault((self.t, key), default)
    
        if sys.version_info < (3,):
            def update(self, *args, **kwargs):
                temp = dict(*args, **kwargs)
                for k, v in temp.iteritems():
                    self.properties[(self.t, k)] = v
        else:
            def update(self, *args, **kwargs):
                temp = dict(*args, **kwargs)
                for k, v in temp.items():
                    self.properties[(self.t, k)] = v
    
        def __delitem__(self, key):
            del self.properties[(self.t, key)]
    
        def clear(self):
            keys = []
            for k in self.properties.items():
                if k[0] == self.t:
                    keys.append(k[1])
            for k in keys:
                del self.properties[(self.t, k)]
    
        def __len__(self):
            count = 0
            for k in self.properties.iterkeys():
                if k[0] == self.t:
                    count += 1
            return count
    
        def __iter__(self):
            return self.iterkeys()
    
        def iterkeys(self):
            for k in self.properties.iterkeys():
                if k[0] == self.t:
                    yield k[0]
    
        def items(self):
            for k, v in self.properties.items():
                if k[0] == self.t:
                    yield k[1], v
    
        if sys.version_info < (3,):
            def has_key(self, key):
                return self.properties.has_key((self.t, key))
    
            def iteritems(self):
                for k, v in self.properties.iteritems():
                    if k[0] == self.t:
                        yield k[1], v
    
        def itervalues(self):
            for k, v in self.properties.iteritems():
                if k[0] == self.t:
                    yield v
    
        def keys(self):
            return [k[1] for k in self.properties.keys() if k[0] == self.t]
    
        if sys.version_info < (3,):
            def values(self):
                return [v for k, v in self.properties.iteritems() if k[0] == self.t]
            def __repr__(self):
                temp = dict([(k[1], v) for k, v in self.properties.iteritems() if k[0] == self.t])
                return repr(temp)
        else:
            def values(self):
                return [v for k, v in self.properties.items() if k[0] == self.t]
            def __repr__(self):
                temp = dict([(k[1], v) for k, v in self.properties.items() if k[0] == self.t])
                return repr(temp)
    
    
        def __getattr__(self, attr):
            return self.__getitem__(attr)
    
        def __setattr__(self, attr, val):
            return self.__setitem__(attr, val)
    
    
    ################################################################################
    # Graph class
    # The main graph interface
    ################################################################################
    
    from .libgraph_tool_core import Vertex, EdgeBase, Vector_bool, Vector_int16_t, 
        Vector_int32_t, Vector_int64_t, Vector_double, Vector_long_double, 
        Vector_string, Vector_size_t, new_vertex_property, new_edge_property, 
        new_graph_property
    
    
    [docs]
    class Graph(object):
        """Generic multigraph class.
    
        This class encapsulates either a directed multigraph (default or if
        ``directed=True``) or an undirected multigraph (if ``directed=False``),
        with optional internal edge, vertex or graph properties.
    
        If ``g`` is specified, the graph (and its internal properties) will be
        copied.
    
        If ``prune`` is set to ``True``, and ``g`` is specified, only the filtered
        graph will be copied, and the new graph object will not be
        filtered. Optionally, a tuple of three booleans can be passed as value to
        ``prune``, to specify a different behavior to vertex, edge, and reversal
        filters, respectively.
    
        If ``vorder`` is specified, it should correspond to a vertex
        :class:`~graph_tool.PropertyMap` specifying the ordering of the vertices in
        the copied graph.
    
        The graph is implemented as an `adjacency list`_, where both vertex and edge
        lists are C++ STL vectors.
    
        .. _adjacency list: http://en.wikipedia.org/wiki/Adjacency_list
    
        """
    
        def __init__(self, g=None, directed=True, prune=False, vorder=None):
            self.__properties = InternalPropertyDict(self)
            self.__graph_properties = PropertyDict(self.__properties, "g")
            self.__vertex_properties = PropertyDict(self.__properties, "v")
            self.__edge_properties = PropertyDict(self.__properties, "e")
            self.__known_properties = {}
            self.__filter_state = {"reversed": False,
                                   "edge_filter": (None, False),
                                   "vertex_filter": (None, False),
                                   "directed": True}
            if g is None:
                self.__graph = libcore.GraphInterface()
                self.set_directed(directed)
    
                # internal index maps
                self.__vertex_index = 
                         PropertyMap(libcore.get_vertex_index(self.__graph), self, "v")
                self.__edge_index = 
                         PropertyMap(libcore.get_edge_index(self.__graph), self, "e")
    
            else:
                if isinstance(prune, bool):
                    vprune = eprune = rprune = prune
                else:
                    vprune, eprune, rprune = prune
                if not (vprune or eprune or rprune):
                    gv = GraphView(g, skip_vfilt=True,
                                   skip_efilt=True)
                    if not rprune:
                        gv.set_reversed(False)
                else:
                    gv = g
    
                # The filters may or may not not be in the internal property maps
                vfilt = g.get_vertex_filter()[0]
                efilt = g.get_edge_filter()[0]
    
                if (vorder is None and ((vfilt is None and efilt is None) or
                                        (not vprune and not eprune))):
                    # Do a simpler, faster copy.
                    self.__graph = libcore.GraphInterface(gv.__graph, False,
                                                          [], [], None)
    
                    # internal index maps
                    self.__vertex_index = 
                             PropertyMap(libcore.get_vertex_index(self.__graph), self, "v")
                    self.__edge_index = 
                             PropertyMap(libcore.get_edge_index(self.__graph), self, "e")
    
                    nvfilt = nefilt = None
                    for k, m in g.properties.items():
                        nmap = self.copy_property(m, g=gv)
                        self.properties[k] = nmap
                        if m is vfilt:
                            nvfilt = nmap
                        if m is efilt:
                            nefilt = nmap
                    if vfilt is not None:
                        if nvfilt is None:
                            nvfilt = self.copy_property(vfilt, g=gv)
                    if efilt is not None:
                        if nefilt is None:
                            nefilt = self.copy_property(efilt, g=gv)
                    self.set_filters(nefilt, nvfilt,
                                     inverted_edges=g.get_edge_filter()[1],
                                     inverted_vertices=g.get_vertex_filter()[1])
                else:
    
                    # Copy all internal properties from original graph.
                    vprops = []
                    eprops = []
                    ef_pos = vf_pos = None
                    for k, m in gv.vertex_properties.items():
                        if not m.is_writable():
                            m = m.copy("int32_t")
                        if not vprune and m is vfilt:
                            vf_pos = len(vprops)
                        vprops.append([_prop("v", gv, m), libcore.any()])
                    for k, m in gv.edge_properties.items():
                        if not m.is_writable():
                            m = m.copy("int32_t")
                        if not eprune and m is efilt:
                            ef_pos = len(eprops)
                        eprops.append([_prop("e", gv, m), libcore.any()])
                    if not vprune and vf_pos is None and vfilt is not None:
                        vf_pos = len(vprops)
                        vprops.append([_prop("v", gv, vfilt), libcore.any()])
                    if not eprune and ef_pos is None and efilt is not None:
                        ef_pos = len(eprops)
                        eprops.append([_prop("e", gv, efilt), libcore.any()])
    
                    # The vertex ordering
                    if vorder is None:
                        vorder = gv.new_vertex_property("int")
                        vorder.fa = numpy.arange(gv.num_vertices())
    
                    # The actual copying of the graph and property maps
                    self.__graph = libcore.GraphInterface(gv.__graph, False,
                                                          vprops,
                                                          eprops,
                                                          _prop("v", gv, vorder))
                    # internal index maps
                    self.__vertex_index = 
                             PropertyMap(libcore.get_vertex_index(self.__graph), self, "v")
                    self.__edge_index = 
                             PropertyMap(libcore.get_edge_index(self.__graph), self, "e")
    
                    # Put the copied properties in the internal dictionary
                    for i, (k, m) in enumerate(gv.vertex_properties.items()):
                        pmap = new_vertex_property(m.value_type() if m.is_writable() else "int32_t",
                                                   self.__graph.get_vertex_index(),
                                                   vprops[i][1])
                        self.vertex_properties[k] = PropertyMap(pmap, self, "v")
    
                    for i, (k, m) in enumerate(gv.edge_properties.items()):
                        pmap = new_edge_property(m.value_type() if m.is_writable() else "int32_t",
                                                 self.__graph.get_edge_index(),
                                                 eprops[i][1])
                        self.edge_properties[k] = PropertyMap(pmap, self, "e")
    
                    for k, v in gv.graph_properties.items():
                        new_p = self.new_graph_property(v.value_type())
                        new_p[self] = v[gv]
                        self.graph_properties[k] = new_p
    
                    epmap = vpmap = None
                    if vf_pos is not None:
                        vpmap = new_vertex_property("bool",
                                                    self.__graph.get_vertex_index(),
                                                    vprops[vf_pos][1])
                        vpmap = PropertyMap(vpmap, self, "v")
                    if ef_pos is not None:
                        epmap = new_edge_property("bool",
                                                  self.__graph.get_edge_index(),
                                                  eprops[ef_pos][1])
                        epmap = PropertyMap(epmap, self, "e")
                    self.set_filters(epmap, vpmap,
                                     inverted_edges=g.get_edge_filter()[1],
                                     inverted_vertices=g.get_vertex_filter()[1])
    
                if not rprune:
                    self.set_reversed(g.is_reversed())
    
                # directedness is always a filter
                self.set_directed(g.is_directed())
    
        def _get_any(self):
            return self.__graph.get_graph_view()
    
    [docs]
        def copy(self):
            """Return a deep copy of self. All :ref:`internal property maps <sec_internal_props>`
            are also copied."""
            return Graph(self)
    
    
        def __copy__(self):
            return self.copy()
    
        def __deepcopy__(self, memo):
            g = self.copy()
            for k, prop in [x for x in g.properties
                            if x[1].value_type == "python::object"]:
                g.properties[k] = copy.deepcopy(prop)
    
        def __repr__(self):
            # provide more useful information
            d = "directed" if self.is_directed() else "undirected"
            fr = ", reversed" if self.is_reversed() and self.is_directed() else ""
            f = ""
            if self.get_edge_filter()[0] is not None:
                f += ", edges filtered by %s" % (str(self.get_edge_filter()))
            if self.get_vertex_filter()[0] is not None:
                f += ", vertices filtered by %s" % (str(self.get_vertex_filter()))
            n = self.num_vertices()
            e = self.num_edges()
            return "<%s object, %s%s, with %d %s and %d edge%s%s at 0x%x>"
                   % (type(self).__name__, d, fr, n,
                      "vertex" if n == 1 else "vertices", e, "" if e == 1 else "s",
                      f, id(self))
    
        # Graph access
        # ============
    
    [docs]
        def vertices(self):
            """Return an :meth:`iterator <iterator.__iter__>` over the vertices.
    
            .. note::
    
               The order of the vertices traversed by the iterator **always**
               corresponds to the vertex index ordering, as given by the
               :attr:`~graph_tool.Graph.vertex_index` property map.
    
            Examples
            --------
            >>> g = gt.Graph()
            >>> vlist = list(g.add_vertex(5))
            >>> vlist2 = []
            >>> for v in g.vertices():
            ...     vlist2.append(v)
            ...
            >>> assert(vlist == vlist2)
    
            """
            return libcore.get_vertices(self.__graph)
    
    
    [docs]
        def vertex(self, i, use_index=True, add_missing=False):
            """Return the vertex with index ``i``. If ``use_index=False``, the
            ``i``-th vertex is returned (which can differ from the vertex with index
            ``i`` in case of filtered graphs).
    
            If ``add_missing == True``, and the vertex does not exist in the graph,
            the necessary number of missing vertices are inserted, and the new
            vertex is returned.
            """
            v = libcore.get_vertex(self.__graph, int(i), use_index)
            if not v.is_valid():
                if add_missing:
                    self.add_vertex(int(i) - self.num_vertices(use_index) + 1)
                    return self.vertex(int(i), use_index)
                raise ValueError("Invalid vertex index: %d" % int(i))
            return v
    
    
    [docs]
        def edge(self, s, t, all_edges=False, add_missing=False):
            """Return the edge from vertex ``s`` to ``t``, if it exists. If
            ``all_edges=True`` then a list is returned with all the parallel edges
            from ``s`` to ``t``, otherwise only one edge is returned.
    
            If ``add_missing == True``, a new edge is created and returned, if none
            currently exists.
    
            This operation will take :math:`O(min(k(s), k(t)))` time, where
            :math:`k(s)` and :math:`k(t)` are the out-degree and in-degree (or
            out-degree if undirected) of vertices :math:`s` and :math:`t`.
    
            """
            s = self.vertex(int(s))
            t = self.vertex(int(t))
            edges = libcore.get_edge(self.__graph, int(s), int(t), all_edges)
            if add_missing and len(edges) == 0:
                edges.append(self.add_edge(s, t))
            if all_edges:
                return edges
            elif len(edges) > 0:
                return edges[0]
            else:
                return None
    
    
    [docs]
        def edges(self):
            """Return an :meth:`iterator <iterator.__iter__>` over the edges.
    
            .. note::
    
               The order of the edges traversed by the iterator **does not**
               necessarily correspond to the edge index ordering, as given by the
               :attr:`~graph_tool.Graph.edge_index` property map. This will only
               happen after :meth:`~graph_tool.Graph.reindex_edges` is called, or in
               certain situations such as just after a graph is loaded from a
               file. However, further manipulation of the graph may destroy the
               ordering.
    
            """
            return libcore.get_edges(self.__graph)
    
    
    [docs]
        def add_vertex(self, n=1):
            """Add a vertex to the graph, and return it. If ``n != 1``, ``n``
            vertices are inserted and an iterator over the new vertices is returned.
            This operation is :math:`O(n)`.
            """
            v = libcore.add_vertex(self.__graph, n)
    
            if n == 1:
                return v
            else:
                pos = self.num_vertices(True) - n
                return (self.vertex(i) for i in range(pos, pos + n))
    
    
    [docs]
        def remove_vertex(self, vertex, fast=False):
            r"""Remove a vertex from the graph. If ``vertex`` is an iterable, it
            should correspond to a sequence of vertices to be removed.
    
            .. note::
    
               If the option ``fast == False`` is given, this operation is
               :math:`O(V + E)` (this is the default). Otherwise it is
               :math:`O(k + k_{	ext{last}})`, where :math:`k` is the (total)
               degree of the vertex being deleted, and :math:`k_{	ext{last}}` is
               the (total) degree of the vertex with the largest index.
    
            .. warning::
    
               This operation may invalidate vertex descriptors. Vertices are always
               indexed contiguously in the range :math:`[0, N-1]`, hence vertex
               descriptors with an index higher than ``vertex`` will be invalidated
               after removal (if ``fast == False``, otherwise only descriptors
               pointing to vertices with the largest index will be invalidated).
    
               Because of this, the only safe way to remove more than one vertex at
               once is to sort them in decreasing index order:
    
               .. code::
    
                   # 'del_list' is a list of vertex descriptors
                   for v in reversed(sorted(del_list)):
                       g.remove_vertex(v)
    
               Alternatively (and preferably), a list (or iterable) may be passed
               directly as the ``vertex`` parameter, and the above is performed
               internally (in C++).
    
            .. warning::
    
               If ``fast == True``, the vertex being deleted is 'swapped' with the
               last vertex (i.e. with the largest index), which will in turn inherit
               the index of the vertex being deleted. All property maps associated
               with the graph will be properly updated, but the index ordering of
               the graph will no longer be the same.
    
            """
            back = self.__graph.get_num_vertices(False) - 1
            is_iter = isinstance(vertex, collections.Iterable)
            if is_iter:
                try:
                    vs = numpy.asarray(vertex, dtype="int64")
                except TypeError:
                    vs = numpy.asarray([int(v) for v in vertex], dtype="int64")
                if len(vs) == 0:
                    return
                vs = numpy.sort(vs)[::-1]
                vmax = vs[0]
                if vs[0] > back:
                    raise ValueError("Vertex index %d is invalid" % vs[0])
            else:
                vmax = int(vertex)
    
            # move / shift all known property maps
            if vmax != back:
                if not is_iter:
                    vs = numpy.asarray((vertex,), dtype="int64")
                for pmap in self.__known_properties.values():
                    if pmap() is not None and pmap().key_type() == "v" and pmap().is_writable():
                        if fast:
                            self.__graph.move_vertex_property(_prop("v", self, pmap()), vs)
                        else:
                            self.__graph.shift_vertex_property(_prop("v", self, pmap()), vs)
    
            if is_iter:
                libcore.remove_vertex_array(self.__graph, vs, fast)
            else:
                libcore.remove_vertex(self.__graph, vertex, fast)
    
    
    [docs]
        def clear_vertex(self, vertex):
            """Remove all in and out-edges from the given vertex."""
            libcore.clear_vertex(self.__graph, int(vertex))
    
    
    [docs]
        def add_edge(self, source, target, add_missing=True):
            """Add a new edge from ``source`` to ``target`` to the graph, and return
            it. This operation is :math:`O(1)`.
    
            If ``add_missing == True``, the source and target vertices are included
            in the graph if they don't yet exist.
            """
            e = libcore.add_edge(self.__graph,
                                 self.vertex(int(source), add_missing=add_missing),
                                 self.vertex(int(target), add_missing=add_missing))
            return e
    
    
    [docs]
        def remove_edge(self, edge):
            r"""Remove an edge from the graph.
    
            .. note::
    
               This operation is normally :math:`O(k_s + k_t)`, where :math:`k_s`
               and :math:`k_s` are the total degrees of the source and target
               vertices, respectively. However, if :meth:`~Graph.set_fast_edge_removal`
               is set to `True`, this operation becomes :math:`O(1)`.
    
            .. warning::
    
               The relative ordering of the remaining edges in the graph is kept
               unchanged, unless :meth:`~Graph.set_fast_edge_removal` is set to
               `True`, in which case it can change.
            """
            return libcore.remove_edge(self.__graph, edge)
    
    
    [docs]
        def add_edge_list(self, edge_list, hashed=False, string_vals=False,
                          eprops=None):
            """Add a list of edges to the graph, given by ``edge_list``, which can
            be an iterator of ``(source, target)`` pairs where both ``source`` and
            ``target`` are vertex indexes, or a :class:`~numpy.ndarray` of shape
            ``(E,2)``, where ``E`` is the number of edges, and each line specifies a 
            ``(source, target)`` pair. If the list references vertices which do not
            exist in the graph, they will be created.
    
            Optionally, if ``hashed == True``, the vertex values in the edge list
            are not assumed to correspond to vertex indices directly. In this case
            they will be mapped to vertex indices according to the order in which
            they are encountered, and a vertex property map with the vertex values
            is returned. If ``string_vals == True``, the algorithm assumes that the
            vertex values are strings. Otherwise, they will be assumed to be numeric
            if ``edge_list`` is a :class:`~numpy.ndarray`, or arbitrary python
            objects if it is not.
    
            If given, ``eprops`` specifies edge property maps that will be filled
            with the remaining values at each row, if there are more than two.
    
            """
            if eprops is None:
                eprops = ()
            else:
                convert = [_converter(x.value_type()) for x in eprops]
                eprops = [_prop("e", self, x) for x in eprops]
                if not isinstance(edge_list, numpy.ndarray):
                    def wrap(elist):
                        for row in elist:
                            yield (val if i < 2 else convert[i - 2](val)
                                   for (i, val) in enumerate(row))
                    edge_list = wrap(edge_list)
            if not hashed:
                if isinstance(edge_list, numpy.ndarray):
                    libcore.add_edge_list(self.__graph, edge_list, eprops)
                else:
                    libcore.add_edge_list_iter(self.__graph, edge_list, eprops)
            else:
                if isinstance(edge_list, numpy.ndarray):
                    vprop = self.new_vertex_property(_gt_type(edge_list.dtype))
                elif string_vals:
                    vprop = self.new_vertex_property("string")
                else:
                    vprop = self.new_vertex_property("object")
                libcore.add_edge_list_hashed(self.__graph, edge_list,
                                             _prop("v", self, vprop),
                                             string_vals, eprops)
                return vprop
    
    
    [docs]
        def set_fast_edge_removal(self, fast=True):
            r"""If ``fast == True`` the fast :math:`O(1)` removal of edges will be
            enabled. This requires an additional data structure of size :math:`O(E)`
            to be kept at all times.  If ``fast == False``, this data structure is
            destroyed."""
            self.__graph.set_keep_epos(fast)
    
    
    [docs]
        def get_fast_edge_removal(self):
            r"""Return whether the fast :math:`O(1)` removal of edges is currently
            enabled."""
            return self.__graph.get_keep_epos()
    
    
    [docs]
        def clear(self):
            """Remove all vertices and edges from the graph."""
            self.__graph.clear()
    
    
    [docs]
        def clear_edges(self):
            """Remove all edges from the graph."""
            self.__graph.clear_edges()
    
    
        # Internal property maps
        # ======================
    
        properties = property(lambda self: self.__properties,
                              doc=
        """Dictionary of internal properties. Keys must always be a tuple, where the
        first element if a string from the set {'v', 'e', 'g'}, representing a
        vertex, edge or graph property, respectively, and the second element is the
        name of the property map.
    
        Examples
        --------
        >>> g = gt.Graph()
        >>> g.properties[("e", "foo")] = g.new_edge_property("vector<double>")
        >>> del g.properties[("e", "foo")]
        """)
    
        # vertex properties
        vertex_properties = property(lambda self: self.__vertex_properties,
                                     doc="Dictionary of internal vertex properties. The keys are the property names.")
        vp = property(lambda self: self.__vertex_properties,
                      doc="Alias to :attr:`~Graph.vertex_properties`.")
    
        # edge properties
        edge_properties = property(lambda self: self.__edge_properties,
                                   doc="Dictionary of internal edge properties. The keys are the property names.")
        ep = property(lambda self: self.__edge_properties,
                      doc="Alias to :attr:`~Graph.edge_properties`.")
    
        # graph properties
        graph_properties = property(lambda self: self.__graph_properties,
                                     doc="Dictionary of internal graph properties. The keys are the property names.")
        gp = property(lambda self: self.__graph_properties,
                      doc="Alias to :attr:`~Graph.graph_properties`.")
    
        def own_property(self, prop):
            """Return a version of the property map 'prop' (possibly belonging to
            another graph) which is owned by the current graph."""
            return PropertyMap(prop._PropertyMap__map, self, prop.key_type())
    
    [docs]
        def list_properties(self):
            """Print a list of all internal properties.
    
            Examples
            --------
            >>> g = gt.Graph()
            >>> g.properties[("e", "foo")] = g.new_edge_property("vector<double>")
            >>> g.vertex_properties["foo"] = g.new_vertex_property("double")
            >>> g.vertex_properties["bar"] = g.new_vertex_property("python::object")
            >>> g.graph_properties["gnat"] = g.new_graph_property("string", "hi there!")
            >>> g.list_properties()
            gnat           (graph)   (type: string, val: hi there!)
            bar            (vertex)  (type: python::object)
            foo            (vertex)  (type: double)
            foo            (edge)    (type: vector<double>)
            """
    
            if len(self.__properties) == 0:
                return
            w = max([len(x[0]) for x in list(self.__properties.keys())]) + 4
            w = w if w > 14 else 14
    
            for k, v in sorted(self.graph_properties.items(), key=lambda k: k[0]):
                pref="%%-%ds (graph)   (type: %%s, val: " % w %  (k, v.value_type())
                val = str(v[self])
                if len(val) > 1000:
                    val = val[:1000] + "..."
                tw = terminal_size()[0]
                val = textwrap.fill(val,
                                    width=max(tw - len(pref), 1))
                val = val.replace("
    ", "
    " + " " * len(pref))
                print("%s%s)" % (pref, val))
            for k, v in sorted(self.vertex_properties.items(), key=lambda k: k[0]):
                print("%%-%ds (vertex)  (type: %%s)" % w % (k, v.value_type()))
            for k, v in sorted(self.edge_properties.items(), key=lambda k: k[0]):
                print("%%-%ds (edge)    (type: %%s)" % w % (k, v.value_type()))
    
    
        # index properties
    
        def _get_vertex_index(self):
            return self.__vertex_index
        vertex_index = property(_get_vertex_index,
                                doc="""Vertex index map.
    
                                It maps for each vertex in the graph an unique
                                integer in the range [0, :meth:`~graph_tool.Graph.num_vertices` - 1].
    
                                .. note::
    
                                    Like :attr:`~graph_tool.Graph.edge_index`, this
                                    is a special instance of a :class:`~graph_tool.PropertyMap`
                                    class, which is **immutable**, and cannot be
                                    accessed as an array.""")
    
        def _get_edge_index(self):
            return self.__edge_index
        edge_index = property(_get_edge_index, doc="""Edge index map.
    
                                It maps for each edge in the graph an unique
                                integer.
    
                                .. note::
    
                                    Like :attr:`~graph_tool.Graph.vertex_index`, this
                                    is a special instance of a :class:`~graph_tool.PropertyMap`
                                    class, which is **immutable**, and cannot be
                                    accessed as an array.
    
                                    Additionally, the indexes may not necessarily
                                    lie in the range [0, :meth:`~graph_tool.Graph.num_edges` - 1].
                                    However this will always happen whenever no
                                    edges are deleted from the graph.""")
    
        def _get_edge_index_range(self):
            return self.__graph.get_edge_index_range()
    
        edge_index_range = property(_get_edge_index_range,
                                    doc="The size of the range of edge indexes.")
    
    [docs]
        def reindex_edges(self):
            """
            Reset the edge indexes so that they lie in the [0, :meth:`~graph_tool.Graph.num_edges` - 1]
            range. The index ordering will be compatible with the sequence returned
            by the :meth:`~graph_tool.Graph.edges` function.
    
            .. WARNING::
    
               Calling this function will invalidate all existing edge property
               maps, if the index ordering is modified! The property maps will still
               be usable, but their contents will still be tied to the old indexes,
               and thus may become scrambled.
            """
            self.__graph.re_index_edges()
    
    
    
    [docs]
        def shrink_to_fit(self):
            """Force the physical capacity of the underlying containers to match the graph's
            actual size, potentially freeing memory back to the system."""
            self.__graph.shrink_to_fit()
    
    
        # Property map creation
    
    [docs]
        def new_property(self, key_type, value_type, vals=None):
    
            """Create a new (uninitialized) vertex property map of key type
            ``key_type`` (``v``, ``e`` or ``g``), value type ``value_type``, and
            return it. If provided, the values will be initialized by ``vals``,
            which should be a sequence.
            """
            if key_type == "v" or key_type == "vertex":
                return self.new_vertex_property(value_type, vals)
            if key_type == "e" or key_type == "edge":
                return self.new_edge_property(value_type, vals)
            if key_type == "g" or key_type == "graph":
                return self.new_graph_property(value_type, vals)
            raise ValueError("unknown key type: " + key_type)
    
    
    [docs]
        def new_vertex_property(self, value_type, vals=None, val=None):
            """Create a new vertex property map of type ``value_type``, and return it. If
            provided, the values will be initialized by ``vals``, which should be
            sequence or by ``val`` which should be  a single value.
            """
            prop = PropertyMap(new_vertex_property(_type_alias(value_type),
                                                   self.__graph.get_vertex_index(),
                                                   libcore.any()),
                               self, "v")
            if vals is not None:
                try:
                    prop.fa = vals
                except ValueError:
                    for v, x in zip(self.vertices(), vals):
                        prop[v] = x
            elif val is not None:
                prop.set_value(val)
            return prop
    
    
        new_vp = _copy_func(new_vertex_property, "new_vp")
        new_vp.__doc__ = "Alias to :func:`~graph_tool.Graph.new_vertex_property`."
    
    [docs]
        def new_edge_property(self, value_type, vals=None, val=None):
            """Create a new edge property map of type ``value_type``, and return it. If
            provided, the values will be initialized by ``vals``, which should be
            sequence or by ``val`` which should be a single value.
            """
            prop = PropertyMap(new_edge_property(_c_str(_type_alias(value_type)),
                                                 self.__graph.get_edge_index(),
                                                 libcore.any()),
                               self, "e")
            if vals is not None:
                try:
                    prop.a = vals
                except ValueError:
                    for e, x in zip(self.edges(), vals):
                        prop[e] = x
            elif val is not None:
                prop.set_value(val)
            return prop
    
    
        new_ep = _copy_func(new_edge_property, "new_ep")
        new_ep.__doc__ = "Alias to :func:`~graph_tool.Graph.new_edge_property`."
    
    [docs]
        def new_graph_property(self, value_type, val=None):
            """Create a new graph property map of type ``value_type``, and return
            it. If ``val`` is not None, the property is initialized to its value."""
            prop = PropertyMap(new_graph_property(_c_str(_type_alias(value_type)),
                                                  self.__graph.get_graph_index(),
                                                  libcore.any()),
                               self, "g")
            if val is not None:
                prop[self] = val
            return prop
    
    
        new_gp = _copy_func(new_graph_property, "new_gp")
        new_gp.__doc__ = "Alias to :func:`~graph_tool.Graph.new_graph_property`."
    
        # property map copying
        @_require("src", PropertyMap)
        @_require("tgt", (PropertyMap, type(None)))
    [docs]
        def copy_property(self, src, tgt=None, value_type=None, g=None, full=True):
            """Copy contents of ``src`` property to ``tgt`` property. If ``tgt`` is None,
            then a new property map of the same type (or with the type given by the
            optional ``value_type`` parameter) is created, and returned. The
            optional parameter ``g`` specifies the source graph to copy properties
            from (defaults to self). If ``full == False``, in the case of filtered
            graphs only the unmasked values are copied (with the remaining ones
            taking the type-dependent default value).
            """
            if tgt is None:
                tgt = self.new_property(src.key_type(),
                                        (src.value_type()
                                         if value_type is None else value_type))
                ret = tgt
            else:
                ret = None
    
            if src.key_type() != tgt.key_type():
                raise ValueError("source and target properties must have the same key type")
    
            if g is None:
                g = self
    
            is_directed = g.is_directed()
            efilt = g.get_edge_filter()
            vfilt = g.get_vertex_filter()
            if g is not self:
                self_is_directed = self.is_directed()
                self_efilt = self.get_edge_filter()
                self_vfilt = self.get_vertex_filter()
            try:
                if full:
                    g.set_directed(True)
                    g.clear_filters()
                    if g is not self:
                        self.set_directed(True)
                        self.clear_filters()
                if src.key_type() == "v":
                    if g.num_vertices() > self.num_vertices():
                        raise ValueError("graphs with incompatible sizes (%d, %d)" %
                                         (g.num_vertices(), self.num_vertices()))
                    try:
                        self.__graph.copy_vertex_property(g.__graph,
                                                          _prop("v", g, src),
                                                          _prop("v", self, tgt))
                    except ValueError:
                        raise ValueError("property maps with the following types are"
                                         " not convertible: %s, %s" %
                                         (src.value_type(), tgt.value_type()))
                elif src.key_type() == "e":
                    if g.num_edges() > self.num_edges():
                        raise ValueError("graphs with incompatible sizes (%d, %d)" %
                                         (g.num_edges(), self.num_edges()))
                    try:
                        self.__graph.copy_edge_property(g.__graph,
                                                        _prop("e", g, src),
                                                        _prop("e", self, tgt))
                    except ValueError:
                        raise ValueError("property maps with the following types are"
                                         " not convertible: %s, %s" %
                                         (src.value_type(), tgt.value_type()))
                else:
                    tgt[self] = src[g]
            finally:
                g.set_directed(is_directed)
                g.set_edge_filter(efilt[0], efilt[1])
                g.set_vertex_filter(vfilt[0], vfilt[1])
                if g is not self:
                    self.set_directed(self_is_directed)
                    self.set_edge_filter(self_efilt[0], self_efilt[1])
                    self.set_vertex_filter(self_vfilt[0], self_vfilt[1])
            return ret
    
    
        # degree property map
        @_limit_args({"deg": ["in", "out", "total"]})
    [docs]
        def degree_property_map(self, deg, weight=None):
            """Create and return a vertex property map containing the degree type
            given by ``deg``, which can be any of ``"in"``, ``"out"``, or ``"total"``.
            If provided, ``weight`` should be an edge :class:`~graph_tool.PropertyMap`
            containing the edge weights which should be summed."""
            pmap = self.__graph.degree_map(deg, _prop("e", self, weight))
            return PropertyMap(pmap, self, "v")
    
    
        # I/O operations
        # ==============
        def __get_file_format(self, file_name):
            fmt = None
            for f in ["gt", "graphml", "xml", "dot", "gml"]:
                names = ["." + f, ".%s.gz" % f, ".%s.bz2" % f, ".%s.xz" % f]
                for name in names:
                    if file_name.endswith(name):
                        fmt = f
                        break
            if fmt is None:
                raise ValueError("cannot determine file format of: " + file_name)
            return fmt
    
    [docs]
        def load(self, file_name, fmt="auto", ignore_vp=None, ignore_ep=None,
                 ignore_gp=None):
            """Load graph from ``file_name`` (which can be either a string or a file-like
            object). The format is guessed from ``file_name``, or can be specified
            by ``fmt``, which can be either "gt", "graphml", "xml", "dot" or "gml".
            (Note that "graphml" and "xml" are synonyms).
    
            If provided, the parameters ``ignore_vp``, ``ignore_ep`` and
            ``ignore_gp``, should contain a list of property names (vertex, edge or
            graph, respectively) which should be ignored when reading the file.
    
            .. warning::
    
               The only file formats which are capable of perfectly preserving the
               internal property maps are "gt" and "graphml". Because of this,
               they should be preferred over the other formats whenever possible.
    
            """
    
            if isinstance(file_name, (str, unicode)):
                file_name = os.path.expanduser(file_name)
                f = open(file_name) # throw the appropriate exception, if not found
            if fmt == 'auto' and isinstance(file_name, (str, unicode)):
                fmt = self.__get_file_format(file_name)
            elif fmt == "auto":
                fmt = "gt"
            if isinstance(file_name, (str, unicode)) and file_name.endswith(".xz"):
                try:
                    import lzma
                    file_name = lzma.open(file_name, mode="rb")
                except ImportError:
                    raise ValueError("lzma compression is only available in Python >= 3.3")
            if fmt == "graphml":
                fmt = "xml"
            if ignore_vp is None:
                ignore_vp = []
            if ignore_ep is None:
                ignore_ep = []
            if ignore_gp is None:
                ignore_gp = []
            if isinstance(file_name, (str, unicode)):
                props = self.__graph.read_from_file(_c_str(file_name), None,
                                                    _c_str(fmt), ignore_vp,
                                                    ignore_ep, ignore_gp)
            else:
                props = self.__graph.read_from_file("", file_name, _c_str(fmt),
                                                    ignore_vp, ignore_ep, ignore_gp)
            for name, prop in props[0].items():
                self.vertex_properties[name] = PropertyMap(prop, self, "v")
            for name, prop in props[1].items():
                self.edge_properties[name] = PropertyMap(prop, self, "e")
            for name, prop in props[2].items():
                self.graph_properties[name] = PropertyMap(prop, self, "g")
            if "_Graph__save__vfilter" in self.graph_properties:
                self.set_vertex_filter(self.vertex_properties["_Graph__save__vfilter"],
                                       self.graph_properties["_Graph__save__vfilter"])
                del self.vertex_properties["_Graph__save__vfilter"]
                del self.graph_properties["_Graph__save__vfilter"]
            if "_Graph__save__efilter" in self.graph_properties:
                self.set_edge_filter(self.edge_properties["_Graph__save__efilter"],
                                     self.graph_properties["_Graph__save__efilter"])
                del self.edge_properties["_Graph__save__efilter"]
                del self.graph_properties["_Graph__save__efilter"]
            if "_Graph__reversed" in self.graph_properties:
                self.set_reversed(True)
                del self.graph_properties["_Graph__reversed"]
            self.shrink_to_fit()
    
    
    [docs]
        def save(self, file_name, fmt="auto"):
            """Save graph to ``file_name`` (which can be either a string or a file-like
            object). The format is guessed from the ``file_name``, or can be
            specified by ``fmt``, which can be either "gt", "graphml", "xml", "dot"
            or "gml".  (Note that "graphml" and "xml" are synonyms).
    
            .. warning::
    
               The only file formats which are capable of perfectly preserving the
               internal property maps are "gt" and "graphml". Because of this,
               they should be preferred over the other formats whenever possible.
    
            """
    
            u = GraphView(self, reversed=self.is_reversed(), skip_vfilt=True,
                          skip_efilt=True)
    
            if self.get_vertex_filter()[0] is not None:
                u.graph_properties["_Graph__save__vfilter"] = self.new_graph_property("bool")
                u.vertex_properties["_Graph__save__vfilter"] =  self.get_vertex_filter()[0]
                u.graph_properties["_Graph__save__vfilter"] = self.get_vertex_filter()[1]
            if self.get_edge_filter()[0] is not None:
                u.graph_properties["_Graph__save__efilter"] = self.new_graph_property("bool")
                u.edge_properties["_Graph__save__efilter"] = self.get_edge_filter()[0]
                u.graph_properties["_Graph__save__efilter"] = self.get_edge_filter()[1]
    
            if self.is_reversed():
                u.graph_properties["_Graph__reversed"] = self.new_graph_property("bool")
                u.graph_properties["_Graph__reversed"] = True
    
            if isinstance(file_name, (str, unicode)):
                file_name = os.path.expanduser(file_name)
            if fmt == 'auto' and isinstance(file_name, (str, unicode)):
                fmt = self.__get_file_format(file_name)
            elif fmt == "auto":
                fmt = "gt"
            if fmt == "graphml":
                fmt = "xml"
    
            if isinstance(file_name, (str, unicode)) and file_name.endswith(".xz"):
                try:
                    import lzma
                    file_name = lzma.open(file_name, mode="wb")
                except ImportError:
                    raise ValueError("lzma compression is only available in Python >= 3.3")
    
            props = [(_c_str(name[1]), prop._PropertyMap__map) for name, prop in 
                     u.__properties.items()]
    
            if isinstance(file_name, (str, unicode)):
                f = open(file_name, "w") # throw the appropriate exception, if
                                         # unable to open
                f.close()
                u.__graph.write_to_file(_c_str(file_name), None, _c_str(fmt), props)
            else:
                u.__graph.write_to_file("", file_name, _c_str(fmt), props)
    
    
    
        # Directedness
        # ============
    
    [docs]
        def set_directed(self, is_directed):
            """Set the directedness of the graph."""
            self.__graph.set_directed(is_directed)
    
    
    [docs]
        def is_directed(self):
            """Get the directedness of the graph."""
            return self.__graph.get_directed()
    
    
        # Reversedness
        # ============
    
    [docs]
        def set_reversed(self, is_reversed):
            """Reverse the direction of the edges, if ``is_reversed`` is ``True``,
            or maintain the original direction otherwise."""
            self.__graph.set_reversed(is_reversed)
    
    
    [docs]
        def is_reversed(self):
            """Return ``True`` if the edges are reversed, and ``False`` otherwise.
            """
            return self.__graph.get_reversed()
    
    
        # Filtering
        # =========
    
    [docs]
        def set_filters(self, eprop, vprop, inverted_edges=False, inverted_vertices=False):
            """Set the boolean properties for edge and vertex filters, respectively.
            Only the vertices and edges with value different than ``True`` are kept in
            the filtered graph. If either the ``inverted_edges`` or ``inverted_vertex``
            options are supplied with the value ``True``, only the edges or vertices
            with value ``False`` are kept. If any of the supplied property is ``None``,
            an empty filter is constructed which allows all edges or vertices."""
    
            if eprop is None and vprop is None:
                return
    
            if eprop is None:
                eprop = self.new_edge_property("bool")
                eprop.a = not inverted_edges
    
            if vprop is None:
                vprop = self.new_vertex_property("bool")
                vprop.a = not inverted_vertices
    
            self.__graph.set_vertex_filter_property(_prop("v", self, vprop),
                                                    inverted_vertices)
            self.__filter_state["vertex_filter"] = (vprop, inverted_vertices)
    
            self.__graph.set_edge_filter_property(_prop("e", self, eprop),
                                                  inverted_edges)
            self.__filter_state["edge_filter"] = (eprop, inverted_edges)
    
    
    [docs]
        def set_vertex_filter(self, prop, inverted=False):
            """Set the vertex boolean filter property. Only the vertices with value
            different than ``False`` are kept in the filtered graph. If the ``inverted``
            option is supplied with value ``True``, only the vertices with value
            ``False`` are kept. If the supplied property is ``None``, the filter is
            replaced by an uniform filter allowing all vertices."""
    
            if prop is not None and prop.value_type() != "bool":
                raise ValueError("filter property map must have 'bool' type")
    
            vfilt = self.own_property(prop) if prop is not None else prop
            efilt = None
    
            eprop = self.get_edge_filter()
            if eprop[0] is None and vfilt is not None:
                efilt = self.new_edge_property("bool")
                efilt.a = True
            if eprop[0] is not None and vfilt is None:
                vfilt = self.new_vertex_property("bool")
                vfilt.a = not inverted
    
            self.__graph.set_vertex_filter_property(_prop("v", self, vfilt),
                                                    inverted)
            self.__filter_state["vertex_filter"] = (vfilt, inverted)
    
            if efilt is not None:
                self.set_edge_filter(efilt)
    
    
    [docs]
        def get_vertex_filter(self):
            """Return a tuple with the vertex filter property and bool value
            indicating whether or not it is inverted."""
            return self.__filter_state["vertex_filter"]
    
    
    [docs]
        def set_edge_filter(self, prop, inverted=False):
            """Set the edge boolean filter property. Only the edges with value
            different than ``False`` are kept in the filtered graph. If the ``inverted``
            option is supplied with value ``True``, only the edges with value ``False``
            are kept. If the supplied property is ``None``, the filter is
            replaced by an uniform filter allowing all edges."""
    
            if prop is not None and prop.value_type() != "bool":
                raise ValueError("filter property map must have 'bool' type")
    
            efilt = self.own_property(prop) if prop is not None else prop
            vfilt = None
    
            vprop = self.get_vertex_filter()
            if vprop[0] is None and efilt is not None:
                vfilt = self.new_vertex_property("bool")
                vfilt.a = True
            if vprop[0] is not None and efilt is None:
                efilt = self.new_edge_property("bool")
                efilt.a = not inverted
            self.__graph.set_edge_filter_property(_prop("e", self, efilt), inverted)
            self.__filter_state["edge_filter"] = (efilt, inverted)
    
            if vfilt is not None:
                self.set_vertex_filter(vfilt)
    
    
    [docs]
        def get_edge_filter(self):
            """Return a tuple with the edge filter property and bool value
            indicating whether or not it is inverted."""
            return self.__filter_state["edge_filter"]
    
    
    [docs]
        def clear_filters(self):
            """Remove vertex and edge filters, and set the graph to the unfiltered
            state."""
            self.__graph.set_vertex_filter_property(_prop("v", self, None), False)
            self.__filter_state["vertex_filter"] = (None, False)
            self.__graph.set_edge_filter_property(_prop("e", self, None), False)
            self.__filter_state["edge_filter"] = (None, False)
    
    
    [docs]
        def purge_vertices(self, in_place=False):
            """Remove all vertices of the graph which are currently being filtered out. This
            operation is not reversible.
    
            If the option ``in_place == True`` is given, the algorithm will remove
            the filtered vertices and re-index all property maps which are tied with
            the graph. This is a slow operation which has an :math:`O(V^2)`
            complexity.
    
            If ``in_place == False``, the graph and its vertex and edge property
            maps are temporarily copied to a new unfiltered graph, which will
            replace the contents of the original graph. This is a fast operation
            with an :math:`O(V + E)` complexity. This is the default behaviour if no
            option is given.
    
            .. note :
    
               The graph will remain in a filtered state after this operation, since
               there might be edge filters present. To return the graph to an
               unfiltered state, use :meth:`~graph_tool.Graph.clear_filters`.
    
            """
            if in_place:
                old_indexes = self.vertex_index.copy("int64_t")
                self.__graph.purge_vertices(_prop("v", self, old_indexes))
                self.set_vertex_filter(None)
                for pmap in self.__known_properties.values():
                    if (pmap() is not None and pmap().key_type() == "v" and
                        pmap().is_writable() and
                        pmap() not in [self.vertex_index, self.edge_index]):
                        self.__graph.re_index_vertex_property(_prop("v", self, pmap()),
                                                              _prop("v", self, old_indexes))
            else:
                stamp = id(self)
                pmaps = []
                for pmap in self.__known_properties.values():
                    if (pmap() is not None and pmap().key_type() in ["v", "e"] and
                        pmap() not in [self.vertex_index, self.edge_index]):
                        pmaps.append(pmap())
                        pname = "__tmp_purge_vertices_%d_%d" % (stamp, id(pmaps[-1]))
                        self.properties[(pmaps[-1].key_type(), pname)] = pmaps[-1]
    
                new_g = Graph(self, prune=(True, False, False))
                self.__graph = new_g.__graph
                self.set_vertex_filter(None)
    
                for pmap in pmaps:
                    pname = "__tmp_purge_vertices_%d_%d" % (stamp, id(pmap))
                    new_pmap = new_g.properties[(pmap.key_type(), pname)]
                    pmap._PropertyMap__map = new_pmap._PropertyMap__map
                    del self.properties[(pmap.key_type(), pname)]
    
                # update edge filter if set
                efilt = self.get_edge_filter()
                if efilt[0] is not None:
                    self.set_edge_filter(efilt[0], efilt[1])
    
    
    [docs]
        def purge_edges(self):
            """Remove all edges of the graph which are currently being filtered out. This
            operation is not reversible.
    
            .. note :
    
               The graph will remain in a filtered state after this operation, since
               there might be vertex filters present. To return the graph to an
               unfiltered state, use :meth:`~graph_tool.Graph.clear_filters`.
    
            """
            self.__graph.purge_edges()
            self.set_edge_filter(None)
    
    
        def get_filter_state(self):
            """Return a copy of the filter state of the graph."""
            self.__filter_state["directed"] = self.is_directed()
            self.__filter_state["reversed"] = self.is_reversed()
            return copy.copy(self.__filter_state)
    
        def set_filter_state(self, state):
            """Set the filter state of the graph."""
            if libcore.graph_filtering_enabled():
                self.set_vertex_filter(state["vertex_filter"][0],
                                       state["vertex_filter"][1])
                self.set_edge_filter(state["edge_filter"][0],
                                     state["edge_filter"][1])
            self.set_directed(state["directed"])
            self.set_reversed(state["reversed"])
    
        # Basic graph statistics
        # ======================
    
    [docs]
        def num_vertices(self, ignore_filter=False):
            """Get the number of vertices.
    
            If ``ignore_filter == True``, vertex filters are ignored.
    
            .. note::
    
                If the vertices are being filtered, and ``ignore_filter == False``,
                this operation is :math:`O(V)`. Otherwise it is :math:`O(1)`.
    
            """
            return self.__graph.get_num_vertices(not ignore_filter)
    
    
    [docs]
        def num_edges(self, ignore_filter=False):
            """Get the number of edges.
    
            If ``ignore_filter == True``, edge filters are ignored.
    
            .. note::
    
                If the edges are being filtered, and ``ignore_filter == False``,
                this operation is :math:`O(E)`. Otherwise it is :math:`O(1)`.
    
            """
            return self.__graph.get_num_edges(not ignore_filter)
    
    
        # Pickling support
        # ================
    
        def __getstate__(self):
            state = dict()
            sio = get_bytes_io()
            self.save(sio, "gt")
            state["blob"] = sio.getvalue()
            return state
    
        def __setstate__(self, state):
            conv_pickle_state(state)
            self.__init__()
            blob = state["blob"]
            if blob != "":
                try:
                    try:
                        sio = get_bytes_io(blob)
                        self.load(sio, "gt")
                    except IOError:
                        sio = get_bytes_io(blob)
                        stream = gzip.GzipFile(fileobj=sio, mode="rb")
                        self.load(stream, "gt")
                except IOError:
                    sio = get_bytes_io(blob)
                    stream = gzip.GzipFile(fileobj=sio, mode="rb")
                    self.load(stream, "xml")
    
    
    
    [docs]
    def load_graph(file_name, fmt="auto", ignore_vp=None, ignore_ep=None,
                   ignore_gp=None):
        """Load a graph from ``file_name`` (which can be either a string or a file-like object).
    
        The format is guessed from ``file_name``, or can be specified by ``fmt``,
        which can be either "gt", "graphml", "xml", "dot" or "gml".  (Note that
        "graphml" and "xml" are synonyms).
    
        If provided, the parameters ``ignore_vp``, ``ignore_ep`` and
        ``ignore_gp``, should contain a list of property names (vertex, edge or
        graph, respectively) which should be ignored when reading the file.
    
        .. warning::
    
           The only file formats which are capable of perfectly preserving the
           internal property maps are "gt" and "graphml". Because of this,
           they should be preferred over the other formats whenever possible.
    
        """
        g = Graph()
        g.load(file_name, fmt, ignore_vp, ignore_ep, ignore_gp)
        return g
    
    
    
    [docs]
    class GraphView(Graph):
        """A view of selected vertices or edges of another graph.
    
        This class uses shared data from another :class:`~graph_tool.Graph`
        instance, but allows for local filtering of vertices and/or edges, edge
        directionality or reversal. See :ref:`sec_graph_views` for more details and
        examples.
    
        The existence of a :class:`~graph_tool.GraphView` object does not affect the
        original graph, except if the graph view is modified (addition or removal of
        vertices or edges), in which case the modification is directly reflected in
        the original graph (and vice-versa), since they both point to the same
        underlying data. Because of this, instances of
        :class:`~graph_tool.PropertyMap` can be used interchangeably with a graph
        and its views.
    
        The argument ``g`` must be an instance of a :class:`~graph_tool.Graph`
        class. If specified, ``vfilt`` and ``efilt`` select which vertices and edges
        are filtered, respectively. These parameters can either be a boolean-valued
        :class:`~graph_tool.PropertyMap` or a :class:`~numpy.ndarray`, which specify
        which vertices/edges are selected, or an unary function that returns
        ``True`` if a given vertex/edge is to be selected, or ``False`` otherwise.
    
        The boolean parameter ``directed`` can be used to set the directionality of
        the graph view. If ``directed == None``, the directionality is inherited
        from ``g``.
    
        If ``reversed == True``, the direction of the edges is reversed.
    
        If ``vfilt`` or ``efilt`` is anything other than a
        :class:`~graph_tool.PropertyMap` instance, the instantiation running time is
        :math:`O(V)` and :math:`O(E)`, respectively. Otherwise, the running time is
        :math:`O(1)`.
    
        If either ``skip_properties``, ``skip_vfilt`` or ``skip_efilt`` is ``True``,
        then the internal properties, vertex filter or edge filter of the original
        graph are ignored, respectively.
    
        """
    
        def __init__(self, g, vfilt=None, efilt=None, directed=None,
                     reversed=False, skip_properties=False, skip_vfilt=False,
                     skip_efilt=False):
            self.__base = g if not isinstance(g, GraphView) else g.base
            Graph.__init__(self)
            # copy graph reference
            self._Graph__graph = libcore.GraphInterface(g._Graph__graph, True,
                                                        [], [],
                                                        _prop("v", g, g.vertex_index))
    
            if not skip_properties:
                for k, v in g.properties.items():
                    self.properties[k] = self.own_property(v)
    
            # set already existing filters
            if not skip_efilt:
                ef = list(g.get_edge_filter())
                if ef[0] is not None:
                    ef[0] = ef[0].copy()
            else:
                ef = [None, False]
            if not skip_vfilt:
                vf = list(g.get_vertex_filter())
                if vf[0] is not None:
                    vf[0] = vf[0].copy()
            else:
                vf = [None, False]
    
            self.set_filters(ef[0], vf[0], ef[1], vf[1])
    
            if efilt is not None:
                if type(efilt) is not PropertyMap:
                    emap = self.new_edge_property("bool")
                    if isinstance(efilt, collections.Iterable):
                        emap.fa = efilt
                    else:
                        for e in g.edges():
                            emap[e] = efilt(e)
                    efilt = emap
                efilt = self.own_property(efilt)
                ef = self.get_edge_filter()
                if ef[0] is not None:
                    if not ef[1]:
                        ef[0].fa = efilt.fa
                    else:
                        ef[0].fa = numpy.logical_not(efilt.fa)
                    self.set_edge_filter(ef[0], ef[1])
                else:
                    self.set_edge_filter(efilt)
    
            if vfilt is not None:
                if type(vfilt) is not PropertyMap:
                    vmap = self.new_vertex_property("bool")
                    if isinstance(vfilt, collections.Iterable):
                        vmap.fa = vfilt
                    else:
                        for v in g.vertices():
                            vmap[v] = vfilt(v)
                    vfilt = vmap
                vfilt = self.own_property(vfilt)
                vf = self.get_vertex_filter()
                if vf[0] is not None:
                    if not vf[1]:
                        vf[0].fa = vfilt.fa
                    else:
                        vf[0].fa = numpy.logical_not(vfilt.fa)
                    self.set_vertex_filter(vf[0], vf[1])
                else:
                    self.set_vertex_filter(vfilt)
    
    
            if directed is not None:
                self.set_directed(directed)
            if reversed:
                self.set_reversed(not g.is_reversed())
    
        def __get_base(self):
            return self.__base
        base = property(__get_base, doc="Base graph.")
    
        # pickling support
        def __getstate__(self):
            return Graph.__getstate__(self)
    
        def __setstate__(self, state):
            g = Graph()
            g.__setstate__(state)
            self.__init__(g)
    
    
    
    [docs]
    def value_types():
        """Return a list of possible properties value types."""
        return libcore.get_property_types()
    
    
    # Vertex and Edge Types
    # =====================
    from .libgraph_tool_core import Vertex, Edge, VertexBase, EdgeBase
    
    def _out_neighbours(self):
        """Return an iterator over the out-neighbours."""
        for e in self.out_edges():
            yield e.target()
    
    def _in_neighbours(self):
        """Return an iterator over the in-neighbours."""
        for e in self.in_edges():
            yield e.source()
    
    def _all_edges(self):
        """Return an iterator over all edges (both in or out)."""
        for e in self.out_edges():
            yield e
        for e in self.in_edges():
            yield e
    
    def _all_neighbours(self):
        """Return an iterator over all neighbours (both in or out)."""
        for v in self.out_neighbours():
            yield v
        for v in self.in_neighbours():
            yield v
    
    def _in_degree(self, weight=None):
        """Return the in-degree of the vertex. If provided, ``weight`` should be a
        scalar edge :class:`~graph_tool.PropertyMap`, and the in-degree will
        correspond to the sum of the weights of the in-edges.
        """
    
        if weight is None:
            return self.__in_degree()
        else:
            return self.__weighted_in_degree(_prop("e", weight.get_graph(), weight))
    
    def _out_degree(self, weight=None):
        """Return the out-degree of the vertex. If provided, ``weight`` should be a
        scalar edge :class:`~graph_tool.PropertyMap`, and the out-degree will
        correspond to the sum of the weights of the out-edges.
        """
    
        if weight is None:
            return self.__out_degree()
        else:
            return self.__weighted_out_degree(_prop("e", weight.get_graph(), weight))
    
    def _vertex_repr(self):
        if not self.is_valid():
            return "<invalid Vertex object at 0x%x>" % (id(self))
        return "<Vertex object with index '%d' at 0x%x>" % (int(self), id(self))
    
    _vertex_doc = """Vertex descriptor.
    
    This class represents a vertex in a :class:`~graph_tool.Graph` instance.
    
    :class:`~graph_tool.Vertex` instances are hashable, and are convertible to
    integers, corresponding to its index (see :attr:`~graph_tool.Graph.vertex_index`).
    """
    
    def _v_eq(v1, v2):
        try:
            return int(v1) == int(v2)
        except TypeError:
            return False
    
    def _v_ne(v1, v2):
        try:
            return int(v1) != int(v2)
        except TypeError:
            return True
    
    def _v_lt(v1, v2):
        try:
            return int(v1) < int(v2)
        except TypeError:
            return False
    
    def _v_gt(v1, v2):
        try:
            return int(v1) > int(v2)
        except TypeError:
            return False
    
    def _v_le(v1, v2):
        try:
            return int(v1) <= int(v2)
        except TypeError:
            return False
    
    def _v_ge(v1, v2):
        try:
            return int(v1) >= int(v2)
        except TypeError:
            return False
    
    if sys.version_info < (3,):
        def _v_long(self):
            return long(int(self))
    
    for Vertex in libcore.get_vlist():
        Vertex.__doc__ = _vertex_doc
        Vertex.out_neighbours = _out_neighbours
        Vertex.in_neighbours = _in_neighbours
        Vertex.all_edges = _all_edges
        Vertex.all_neighbours = _all_neighbours
        Vertex.in_degree = _in_degree
        Vertex.out_degree = _out_degree
        try:
            Vertex.is_valid.__doc__ = "Returns ``True`` if the descriptor corresponds to an existing vertex in the graph, ``False`` otherwise."
        except AttributeError:
            pass
        Vertex.__repr__ = _vertex_repr
        Vertex.__eq__ = _v_eq
        Vertex.__ne__ = _v_ne
        Vertex.__lt__ = _v_lt
        Vertex.__gt__ = _v_gt
        Vertex.__le__ = _v_le
        Vertex.__ge__ = _v_ge
        if sys.version_info < (3,):
            Vertex.__long__ = _v_long
    
    _edge_doc = """Edge descriptor.
    
    This class represents an edge in a :class:`~graph_tool.Graph`.
    
    :class:`~graph_tool.Edge` instances are hashable, iterable and thus are
    convertible to a tuple, which contains the source and target vertices.
    """
    
    def _edge_iter(self):
        """Iterate over the source and target"""
        for v in (self.source(), self.target()):
            yield v
    
    def _edge_repr(self):
        if not self.is_valid():
            return "<invalid Edge object at 0x%x>" % (id(self))
    
        return ("<Edge object with source '%d' and target '%d'" +
                " at 0x%x>") % (int(self.source()), int(self.target()), id(self))
    
    # There are several edge classes... me must cycle through them all to modify
    # them.
    
    for Edge in libcore.get_elist():
        Edge.__repr__ = _edge_repr
        Edge.__iter__ = _edge_iter
        Edge.__doc__ = _edge_doc
        try:
            Edge.is_valid.__doc__ = "Returns ``True`` if the descriptor corresponds to an existing edge in the graph, ``False`` otherwise."
            Edge.source.__doc__ = "Returns the source of the edge (a :class:`~graph_tool.Vertex` instance)."
            Edge.target.__doc__ = "Returns the target of the edge (a :class:`~graph_tool.Vertex` instance)."
        except AttributeError:
            pass
    
    # some shenanigans to make it seem there is only a single edge and vertex class
    EdgeBase.__doc__ = Edge.__doc__
    EdgeBase.source = Edge.source
    EdgeBase.target = Edge.target
    EdgeBase.is_valid = Edge.is_valid
    Edge = EdgeBase
    Edge.__name__ = "Edge"
    
    VertexBase.__doc__ = Vertex.__doc__
    VertexBase.out_neighbours = Vertex.out_neighbours
    VertexBase.in_neighbours = Vertex.in_neighbours
    VertexBase.all_edges = Vertex.all_edges
    VertexBase.all_neighbours = Vertex.all_neighbours
    VertexBase.in_degree = Vertex.in_degree
    VertexBase.out_degree = Vertex.out_degree
    VertexBase.is_valid = Vertex.is_valid
    Vertex = VertexBase
    Vertex.__name__ = "Vertex"
    
    
    # Add convenience function to vector classes
    def _get_array_view(self):
        return self.get_array()[:]
    
    
    def _set_array_view(self, v):
        self.get_array()[:] = v
    
    vector_types = [Vector_bool, Vector_int16_t, Vector_int32_t, Vector_int64_t,
                    Vector_double, Vector_long_double, Vector_size_t]
    for vt in vector_types:
        vt.a = property(_get_array_view, _set_array_view,
                        doc=r"""Shortcut to the `get_array` method as an attribute.""")
        vt.__repr__ = lambda self: self.a.__repr__()
    Vector_string.a = None
    Vector_string.get_array = lambda self: None
    Vector_string.__repr__ = lambda self: repr(list(self))
    
    
    # Global RNG
    
    _rng = libcore.get_rng((numpy.random.randint(0, sys.maxsize) + os.getpid()) % sys.maxsize)
    
    def seed_rng(seed):
        "Seed the random number generator used by graph-tool's algorithms."
        import graph_tool
        graph_tool._rng = libcore.get_rng(int(seed))
    
    def _get_rng():
        global _rng
        return _rng
    
    # OpenMP Setup
    
    def openmp_enabled():
        """Return `True` if OpenMP was enabled during compilation."""
        return libcore.openmp_enabled()
    
    def openmp_get_num_threads():
        """Return the number of OpenMP threads."""
        return libcore.openmp_get_num_threads()
    
    def openmp_set_num_threads(n):
        """Set the number of OpenMP threads."""
        return libcore.openmp_set_num_threads(n)
    
    def openmp_get_schedule():
        """Return the runtime OpenMP schedule and chunk size. The schedule can by
        any of: `"static"`, `"dynamic"`, `"guided"`, `"auto"`."""
        return libcore.openmp_get_schedule()
    
    def openmp_set_schedule(schedule, chunk=0):
        """Set the runtime OpenMP schedule and chunk size. The schedule can by
        any of: `"static"`, `"dynamic"`, `"guided"`, `"auto"`."""
        return libcore.openmp_set_schedule(schedule, chunk)
    
    if openmp_enabled() and os.environ.get("OMP_SCHEDULE") is None:
        openmp_set_schedule("static", 0)
    
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  • 原文地址:https://www.cnblogs.com/leezx/p/5571345.html
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