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  • 默认字典defaultdict

    默认字典defaultdict
    defaultdict是对字典的类型的补充,他默认给字典的值设置了一个类型。
    class defaultdict(dict):
    """
    defaultdict(default_factory[, ...]) --> dict with default factory
    The default factory is called without arguments to produce
    a new value when a key is not present, in __getitem__ only.
    A defaultdict compares equal to a dict with the same items.
    All remaining arguments are treated the same as if they were
    passed to the dict constructor, including keyword arguments.
    """
    def copy(self): # real signature unknown; restored from __doc__
    """ D.copy() -> a shallow copy of D. """
    pass
    def __copy__(self, *args, **kwargs): # real signature unknown
    """ D.copy() -> a shallow copy of D. """
    pass
    def __getattribute__(self, name): # real signature unknown; restored from __doc__
    """ x.__getattribute__('name') <==> x.name """
    pass
    def __init__(self, default_factory=None, **kwargs): # known case of _collections.defaultdict.__init__
    """
    defaultdict(default_factory[, ...]) --> dict with default factory
    The default factory is called without arguments to produce
    a new value when a key is not present, in __getitem__ only.
    A defaultdict compares equal to a dict with the same items.
    All remaining arguments are treated the same as if they were
    passed to the dict constructor, including keyword arguments.
    # (copied from class doc)
    """
    pass
    def __missing__(self, key): # real signature unknown; restored from __doc__
    """
    __missing__(key) # Called by __getitem__ for missing key; pseudo-code:
    if self.default_factory is None: raise KeyError((key,))
    self[key] = value = self.default_factory()
    return value
    """
    pass
    def __reduce__(self, *args, **kwargs): # real signature unknown
    """ Return state information for pickling. """
    pass
    def __repr__(self): # real signature unknown; restored from __doc__
    """ x.__repr__() <==> repr(x) """
    pass
    default_factory = property(lambda self: object(), lambda self, v: None, lambda self: None) # default
    """Factory for default value called by __missing__()."""
    原生字典:
    values = [11, 22, 33,44,55,66,77,88,99,90]
    my_dict = {}
    for value in values:
    if value>66:
    if my_dict.has_key('k1'):
    my_dict['k1'].append(value)
    else:
    my_dict['k1'] = [value]
    else:
    if my_dict.has_key('k2'):
    my_dict['k2'].append(value)
    else:
    my_dict['k2'] = [value]
    默认字典:
    from collections import defaultdict
    values = [11, 22, 33,44,55,66,77,88,99,90]
    my_dict = defaultdict(list)
    for value in values:
    if value>66:
    my_dict['k1'].append(value)
    else:
    my_dict['k2'].append(value)
    defaultdict字典解决方法
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  • 原文地址:https://www.cnblogs.com/skyzy/p/9433431.html
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