python 学习之数据类型和for循环

一 基本数据类型

比如数字来说:

　　数字的方法都放在int类中，而数字是类的实例化。 如上图所示

1，整型

n1=4
n2=4
print(n1.__add__(n2))

a=18
print("the num 18 's bit is:",a.bit_length())

 class int(object):
    """
    int(x=0) -> integer
    int(x, base=10) -> integer
    
    Convert a number or string to an integer, or return 0 if no arguments
    are given.  If x is a number, return x.__int__().  For floating point
    numbers, this truncates towards zero.
    
    If x is not a number or if base is given, then x must be a string,
    bytes, or bytearray instance representing an integer literal in the
    given base.  The literal can be preceded by '+' or '-' and be surrounded
    by whitespace.  The base defaults to 10.  Valid bases are 0 and 2-36.
    Base 0 means to interpret the base from the string as an integer literal.
    >>> int('0b100', base=0)
    4
    """
    def bit_length(self): # real signature unknown; restored from __doc__
        """ 计算给出数字的二进制最小位数
        int.bit_length() -> int
        
        Number of bits necessary to represent self in binary.
        >>> bin(37)
        '0b100101'
        >>> (37).bit_length()
        6
        """
        return 0

    def conjugate(self, *args, **kwargs): # real signature unknown
        """返回该复数的共轭复数"""
 """ Returns self, the complex conjugate of any int. """
    pass

@classmethod # known case
def from_bytes(cls, bytes, byteorder, *args, **kwargs): # real signature unknown; NOTE: unreliably restored from __doc__ 
    """
    int.from_bytes(bytes, byteorder, *, signed=False) -> int
    
    Return the integer represented by the given array of bytes.
    
    The bytes argument must be a bytes-like object (e.g. bytes or bytearray).
    
    The byteorder argument determines the byte order used to represent the
    integer.  If byteorder is 'big', the most significant byte is at the
    beginning of the byte array.  If byteorder is 'little', the most
    significant byte is at the end of the byte array.  To request the native
    byte order of the host system, use `sys.byteorder' as the byte order value.
    
    The signed keyword-only argument indicates whether two's complement is
    used to represent the integer.
    """
    pass

def to_bytes(self, length, byteorder, *args, **kwargs): # real signature unknown; NOTE: unreliably restored from __doc__ 
    """
    int.to_bytes(length, byteorder, *, signed=False) -> bytes
    
    Return an array of bytes representing an integer.
    
    The integer is represented using length bytes.  An OverflowError is
    raised if the integer is not representable with the given number of
    bytes.
    
    The byteorder argument determines the byte order used to represent the
    integer.  If byteorder is 'big', the most significant byte is at the
    beginning of the byte array.  If byteorder is 'little', the most
    significant byte is at the end of the byte array.  To request the native
    byte order of the host system, use `sys.byteorder' as the byte order value.
    
    The signed keyword-only argument determines whether two's complement is
    used to represent the integer.  If signed is False and a negative integer
    is given, an OverflowError is raised.
    """
    pass

def __abs__(self, *args, **kwargs): # real signature unknown
""" 返回绝对值 """

    """ abs(self) """
    pass

def __add__(self, *args, **kwargs): # real signature unknown
    """ Return self+value. """
    pass

def __and__(self, *args, **kwargs): # real signature unknown
    """ Return self&value. """
    pass

def __bool__(self, *args, **kwargs): # real signature unknown
    """ self != 0 """
    pass

def __ceil__(self, *args, **kwargs): # real signature unknown
    """ Ceiling of an Integral returns itself. """
    pass

def __divmod__(self, *args, **kwargs): # real signature unknown
    """
相除，得到商和余数组成的元组
Return divmod(self, value). """
    pass

def __eq__(self, *args, **kwargs): # real signature unknown
    """ Return self==value. """
    pass

def __float__(self, *args, **kwargs): # real signature unknown
    """
转换为浮点类型
float(self) """
    pass

def __floordiv__(self, *args, **kwargs): # real signature unknown
    """ Return self//value. """
    pass

def __floor__(self, *args, **kwargs): # real signature unknown
    """ Flooring an Integral returns itself. """
    pass

def __format__(self, *args, **kwargs): # real signature unknown
    pass

def __getattribute__(self, *args, **kwargs): # real signature unknown
    """ Return getattr(self, name). """
    pass

def __getnewargs__(self, *args, **kwargs): # real signature unknown
    pass

def __ge__(self, *args, **kwargs): # real signature unknown
    """ Return self>=value. """
    pass

def __gt__(self, *args, **kwargs): # real signature unknown
    """ Return self>value. """
    pass

def __hash__(self, *args, **kwargs): # real signature unknown
    """ Return hash(self). """
    pass

def __index__(self, *args, **kwargs): # real signature unknown
    """ Return self converted to an integer, if self is suitable for use as an index into a list. """
    pass

def __init__(self, x, base=10): # known special case of int.__init__
    """
    int(x=0) -> integer
    int(x, base=10) -> integer
    
    Convert a number or string to an integer, or return 0 if no arguments
    are given.  If x is a number, return x.__int__().  For floating point
    numbers, this truncates towards zero.
    
    If x is not a number or if base is given, then x must be a string,
    bytes, or bytearray instance representing an integer literal in the
    given base.  The literal can be preceded by '+' or '-' and be surrounded
    by whitespace.  The base defaults to 10.  Valid bases are 0 and 2-36.
    Base 0 means to interpret the base from the string as an integer literal.
    >>> int('0b100', base=0)
    4
    # (copied from class doc)
    """
    pass

def __int__(self, *args, **kwargs): # real signature unknown
    """ int(self) """
    pass

def __invert__(self, *args, **kwargs): # real signature unknown
    """ ~self """
    pass

def __le__(self, *args, **kwargs): # real signature unknown
    """ Return self<=value. """
    pass

def __lshift__(self, *args, **kwargs): # real signature unknown
    """ Return self<<value. """
    pass

def __lt__(self, *args, **kwargs): # real signature unknown
    """ Return self<value. """
    pass

def __mod__(self, *args, **kwargs): # real signature unknown
    """ Return self%value. """
    pass

def __mul__(self, *args, **kwargs): # real signature unknown
    """ Return self*value. """
    pass

def __neg__(self, *args, **kwargs): # real signature unknown
    """ -self """
    pass

@staticmethod # known case of __new__
def __new__(*args, **kwargs): # real signature unknown
    """ Create and return a new object.  See help(type) for accurate signature. """
    pass

def __ne__(self, *args, **kwargs): # real signature unknown
    """ Return self!=value. """
    pass

def __or__(self, *args, **kwargs): # real signature unknown
    """ Return self|value. """
    pass

def __pos__(self, *args, **kwargs): # real signature unknown
    """ +self """
    pass

def __pow__(self, *args, **kwargs): # real signature unknown
    """ Return pow(self, value, mod). """
    pass

def __radd__(self, *args, **kwargs): # real signature unknown
    """ Return value+self. """
    pass

def __rand__(self, *args, **kwargs): # real signature unknown
    """ Return value&self. """
    pass

def __rdivmod__(self, *args, **kwargs): # real signature unknown
    """ Return divmod(value, self). """
    pass

def __repr__(self, *args, **kwargs): # real signature unknown
    """ Return repr(self). """
    pass

def __rfloordiv__(self, *args, **kwargs): # real signature unknown
    """ Return value//self. """
    pass

def __rlshift__(self, *args, **kwargs): # real signature unknown
    """ Return value<<self. """
    pass

def __rmod__(self, *args, **kwargs): # real signature unknown
    """ Return value%self. """
    pass

def __rmul__(self, *args, **kwargs): # real signature unknown
    """ Return value*self. """
    pass

def __ror__(self, *args, **kwargs): # real signature unknown
    """ Return value|self. """
    pass

def __round__(self, *args, **kwargs): # real signature unknown
    """
    Rounding an Integral returns itself.
    Rounding with an ndigits argument also returns an integer.
    """
    pass

def __rpow__(self, *args, **kwargs): # real signature unknown
    """ Return pow(value, self, mod). """
    pass

def __rrshift__(self, *args, **kwargs): # real signature unknown
    """ Return value>>self. """
    pass

def __rshift__(self, *args, **kwargs): # real signature unknown
    """ Return self>>value. """
    pass

def __rsub__(self, *args, **kwargs): # real signature unknown
    """ Return value-self. """
    pass

def __rtruediv__(self, *args, **kwargs): # real signature unknown
    """ Return value/self. """
    pass

def __rxor__(self, *args, **kwargs): # real signature unknown
    """ Return value^self. """
    pass

def __sizeof__(self, *args, **kwargs): # real signature unknown
    """ Returns size in memory, in bytes """
    pass

def __str__(self, *args, **kwargs): # real signature unknown
    """ Return str(self). """
    pass

def __sub__(self, *args, **kwargs): # real signature unknown
    """ Return self-value. """
    pass

def __truediv__(self, *args, **kwargs): # real signature unknown
    """ Return self/value. """
    pass

def __trunc__(self, *args, **kwargs): # real signature unknown
    """ Truncating an Integral returns itself. """
    pass

def __xor__(self, *args, **kwargs): # real signature unknown
    """ Return self^value. """
    pass

denominator = property(lambda self: object(), lambda self, v: None, lambda self: None)  # default
"""the denominator of a rational number in lowest terms"""

imag = property(lambda self: object(), lambda self, v: None, lambda self: None)  # default
"""the imaginary part of a complex number"""

numerator = property(lambda self: object(), lambda self, v: None, lambda self: None)  # default
"""the numerator of a rational number in lowest terms"""

real = property(lambda self: object(), lambda self, v: None, lambda self: None)  # default
"""the real part of a complex number"""

2、布尔值

　　真或假

　　1 或 0

3、字符串

"hello world"

万恶的字符串拼接：

　　python中的字符串在C语言中体现为是一个字符数组，每次创建字符串时候需要在内存中开辟一块连续的空，并且一旦需要修改字符串的话，就需要再次开辟空间，万恶的+号每出现一次就会在内从中重新开辟一块空间。

字符串格式化

name = "alex"
print "i am %s " % name
  
#输出: i am alex

PS: 字符串是 %s;整数 %d;浮点数%f

字符串常用功能：  后面有练习

• 移除空白
• 分割
• 长度
• 索引
• 切片   

class str(object):
    """
    str(object='') -> str
    str(bytes_or_buffer[, encoding[, errors]]) -> str
    
    Create a new string object from the given object. If encoding or
    errors is specified, then the object must expose a data buffer
    that will be decoded using the given encoding and error handler.
    Otherwise, returns the result of object.__str__() (if defined)
    or repr(object).
    encoding defaults to sys.getdefaultencoding().
    errors defaults to 'strict'.
    """
    def capitalize(self): # real signature unknown; restored from __doc__
        """ #将 字符串首字母 小写改大写
        S.capitalize() -> str
        
        Return a capitalized version of S, i.e. make the first character
        have upper case and the rest lower case.

        """
        return ""

    def casefold(self): # real signature unknown; restored from __doc__
        """
        S.casefold() -> str
        
        Return a version of S suitable for caseless comparisons.
        """
        return ""

    def center(self, width, fillchar=None): # real signature unknown; restored from __doc__
        """ 可以为字符串 填充自定字符 长度=字符+指定字符
        S.center(width[, fillchar]) -> str
        
        Return S centered in a string of length width. Padding is
        done using the specified fill character (default is a space)
        """
        return ""

    def count(self, sub, start=None, end=None): # real signature unknown; restored from __doc__
        """  下面是详细参数： 
　　　　　　　　子串：是要搜索的子串。

　　　　　　　　开始：从该指数开始搜索。第一个字符从索引0开始。通过默认搜索引擎从索引0开始。

　　　　　　　　结束：搜索从该指数结束。第一个字符从索引0开始。默认情况下，搜索结束，在最后一个索引。


        S.count(sub[, start[, end]]) -> int
        
        Return the number of non-overlapping occurrences of substring sub in
        string S[start:end].  Optional arguments start and end are
        interpreted as in slice notation.
        """
        return 0

    def encode(self, encoding='utf-8', errors='strict'): # real signature unknown; restored from __doc__
        """ 编码 上面有介绍
        S.encode(encoding='utf-8', errors='strict') -> bytes
        
        Encode S using the codec registered for encoding. Default encoding
        is 'utf-8'. errors may be given to set a different error
        handling scheme. Default is 'strict' meaning that encoding errors raise
        a UnicodeEncodeError. Other possible values are 'ignore', 'replace' and
        'xmlcharrefreplace' as well as any other name registered with
        codecs.register_error that can handle UnicodeEncodeErrors.
        """
        return b""

    def endswith(self, suffix, start=None, end=None): # real signature unknown; restored from __doc__
        """  以 某个字符结束
　　　　　　　　　　suffix -- 该参数可以是一个字符串或者是一个元素。

　　　　　　start -- 字符串中的开始位置。

　　　　　　end -- 字符中结束位置。

 

　　　　　　返回值

 

　　　　　　如果字符串含有指定的后缀返回True，否则返回False。



        S.endswith(suffix[, start[, end]]) -> bool
        
        Return True if S ends with the specified suffix, False otherwise.
        With optional start, test S beginning at that position.
        With optional end, stop comparing S at that position.
        suffix can also be a tuple of strings to try.
        """
        return False

    def expandtabs(self, tabsize=8): # real signature unknown; restored from __doc__
        """ 把tab转换成空格
        S.expandtabs(tabsize=8) -> str
        
        Return a copy of S where all tab characters are expanded using spaces.
        If tabsize is not given, a tab size of 8 characters is assumed.
        """
        return ""

    def find(self, sub, start=None, end=None): # real signature unknown; restored from __doc__
        """
find(str, pos_start, pos_end)

解释：

　　str:被查找“字串”

　　pos_start:查找的首字母位置（从0开始计数。默认：0）

　　pos_end: 查找的末尾位置（默认-1）

返回值：如果查到：返回查找的第一个出现的位置。否则，返回-1。



        S.find(sub[, start[, end]]) -> int
        
        Return the lowest index in S where substring sub is found,
        such that sub is contained within S[start:end].  Optional
        arguments start and end are interpreted as in slice notation.
        
        Return -1 on failure.
        """
        return 0

    def format(*args, **kwargs): # known special case of str.format
        """  占位符  类似变量引用
　　　　　　s = "print hell {0} ,age {1}"
　　　　　　print(s.format('alex',19))


        S.format(*args, **kwargs) -> str
        
        Return a formatted version of S, using substitutions from args and kwargs.
        The substitutions are identified by braces ('{' and '}').
        """
        pass

    def format_map(self, mapping): # real signature unknown; restored from __doc__
        """字符串格式化，动态参数，将函数式编程时细说
        S.format_map(mapping) -> str
        
        Return a formatted version of S, using substitutions from mapping.
        The substitutions are identified by braces ('{' and '}').
        """
        return ""

    def index(self, sub, start=None, end=None): # real signature unknown; restored from __doc__
        """ #跟find类似但是 没有找到的话会报错。 而find是返回-1
        S.index(sub[, start[, end]]) -> int
        
        Like S.find() but raise ValueError when the substring is not found.
        """
        return 0

    def isalnum(self): # real signature unknown; restored from __doc__
        """ #判断是否是数字和字母
        S.isalnum() -> bool
        
        Return True if all characters in S are alphanumeric
        and there is at least one character in S, False otherwise.
        """
        return False

    def isalpha(self): # real signature unknown; restored from __doc__
        """是否是字母 
        S.isalpha() -> bool
        
        Return True if all characters in S are alphabetic
        and there is at least one character in S, False otherwise.
        """
        return False

    def isdecimal(self): # real signature unknown; restored from __doc__
        """
        S.isdecimal() -> bool
        
        Return True if there are only decimal characters in S,
        False otherwise.
        """
        return False

    def isdigit(self): # real signature unknown; restored from __doc__
        """ 是否是数字
        S.isdigit() -> bool
        
        Return True if all characters in S are digits
        and there is at least one character in S, False otherwise.
        """
        return False

    def isidentifier(self): # real signature unknown; restored from __doc__
        """
        S.isidentifier() -> bool
        
        Return True if S is a valid identifier according
        to the language definition.
        
        Use keyword.iskeyword() to test for reserved identifiers
        such as "def" and "class".
        """
        return False

    def islower(self): # real signature unknown; restored from __doc__
        """是否小写字母
        S.islower() -> bool
        
        Return True if all cased characters in S are lowercase and there is
        at least one cased character in S, False otherwise.
        """
        return False

    def isnumeric(self): # real signature unknown; restored from __doc__
        """
        S.isnumeric() -> bool
        
        Return True if there are only numeric characters in S,
        False otherwise.
        """
        return False

    def isprintable(self): # real signature unknown; restored from __doc__
        """
        S.isprintable() -> bool
        
        Return True if all characters in S are considered
        printable in repr() or S is empty, False otherwise.
        """
        return False

    def isspace(self): # real signature unknown; restored from __doc__
        """是否是空格
        S.isspace() -> bool
        
        Return True if all characters in S are whitespace
        and there is at least one character in S, False otherwise.
        """
        return False

    def istitle(self): # real signature unknown; restored from __doc__
        """ 是否是标题  字符串开头是大写 后面是小写
        S.istitle() -> bool
        
        Return True if S is a titlecased string and there is at least one
        character in S, i.e. upper- and titlecase characters may only
        follow uncased characters and lowercase characters only cased ones.
        Return False otherwise.
        """
        return False

    def isupper(self): # real signature unknown; restored from __doc__
        """ 是否是大写
        S.isupper() -> bool
        
        Return True if all cased characters in S are uppercase and there is
        at least one cased character in S, False otherwise.
        """
        return False

    def join(self, iterable): # real signature unknown; restored from __doc__
        """ 拼接 后面有例子

        S.join(iterable) -> str
        
        Return a string which is the concatenation of the strings in the
        iterable.  The separator between elements is S.
        """
        return ""

    def ljust(self, width, fillchar=None): # real signature unknown; restored from __doc__
        """ 内容左对齐，右侧填充
　　　　ljust()方法语法：

 

　　　　str.ljust(width[, fillchar])

 

　　　　参数

 

　　　　width -- 指定字符串长度。

　　　　fillchar -- 填充字符，默认为空格。

 

　　　　返回值

 

　　　　返回一个原字符串左对齐,并使用空格填充至指定长度的新字符串。如果指定的长度小于原字符串的长度则返回原字符串。

 S.ljust(width[, fillchar]) -> str Return S left-justified in a Unicode string of length width. Padding is done using the specified fill character (default is a space). """ return "" def lower(self): # real signature unknown; restored from __doc__ """ 转换为小写 S.lower() -> str Return a copy of the string S converted to lowercase. """ return "" def lstrip(self, chars=None): # real signature unknown; restored from __doc__ """ 去除左侧开头空白 S.lstrip([chars]) -> str Return a copy of the string S with leading whitespace removed. If chars is given and not None, remove characters in chars instead. """ return "" def maketrans(self, *args, **kwargs): # real signature unknown """ Return a translation table usable for str.translate(). If there is only one argument, it must be a dictionary mapping Unicode ordinals (integers) or characters to Unicode ordinals, strings or None. Character keys will be then converted to ordinals. If there are two arguments, they must be strings of equal length, and in the resulting dictionary, each character in x will be mapped to the character at the same position in y. If there is a third argument, it must be a string, whose characters will be mapped to None in the result. """ pass def partition(self, sep): # real signature unknown; restored from __doc__ """ 以指定 字符 开始分割 指定的字符也显示 S.partition(sep) -> (head, sep, tail) Search for the separator sep in S, and return the part before it, the separator itself, and the part after it. If the separator is not found, return S and two empty strings. """ pass def replace(self, old, new, count=None): # real signature unknown; restored from __doc__ """ 替换
　　　　old -- 将被替换的子字符串。

　　　　new -- 新字符串，用于替换old子字符串。

　　　　max -- 可选字符串, 替换不超过 max 次

　　　　返回值

　　　　返回字符串中的 old（旧字符串） 替换成 new(新字符串)后生成的新字符串，如果指定第三个参数max，则替换不超过 max 次。



        S.replace(old, new[, count]) -> str
        
        Return a copy of S with all occurrences of substring
        old replaced by new.  If the optional argument count is
        given, only the first count occurrences are replaced.
        """
        return ""

    def rfind(self, sub, start=None, end=None): # real signature unknown; restored from __doc__
        """ 从右开始查找
        S.rfind(sub[, start[, end]]) -> int
        
        Return the highest index in S where substring sub is found,
        such that sub is contained within S[start:end].  Optional
        arguments start and end are interpreted as in slice notation.
        
        Return -1 on failure.
        """
        return 0

    def rindex(self, sub, start=None, end=None): # real signature unknown; restored from __doc__
        """ 顾名思义从右侧匹配
        S.rindex(sub[, start[, end]]) -> int
        
        Like S.rfind() but raise ValueError when the substring is not found.
        """
        return 0

    def rjust(self, width, fillchar=None): # real signature unknown; restored from __doc__
        """ 从右侧 填充
        S.rjust(width[, fillchar]) -> str
        
        Return S right-justified in a string of length width. Padding is
        done using the specified fill character (default is a space).
        """
        return ""

    def rpartition(self, sep): # real signature unknown; restored from __doc__
        """ 从右侧开始找到 分割 分割字符也显示
        S.rpartition(sep) -> (head, sep, tail)
        
        Search for the separator sep in S, starting at the end of S, and return
        the part before it, the separator itself, and the part after it.  If the
        separator is not found, return two empty strings and S.
        """
        pass

    def rsplit(self, sep=None, maxsplit=-1): # real signature unknown; restored from __doc__
        """ 从右侧开始分割 sep是指定几个
        S.rsplit(sep=None, maxsplit=-1) -> list of strings
        
        Return a list of the words in S, using sep as the
        delimiter string, starting at the end of the string and
        working to the front.  If maxsplit is given, at most maxsplit
        splits are done. If sep is not specified, any whitespace string
        is a separator.
        """
        return []

    def rstrip(self, chars=None): # real signature unknown; restored from __doc__
        """ 从右侧 去除结尾的空格
        S.rstrip([chars]) -> str
        
        Return a copy of the string S with trailing whitespace removed.
        If chars is given and not None, remove characters in chars instead.
        """
        return ""

    def split(self, sep=None, maxsplit=-1): # real signature unknown; restored from __doc__
        """ 分割 sep是几个算分割符
        S.split(sep=None, maxsplit=-1) -> list of strings
        
        Return a list of the words in S, using sep as the
        delimiter string.  If maxsplit is given, at most maxsplit
        splits are done. If sep is not specified or is None, any
        whitespace string is a separator and empty strings are
        removed from the result.
        """
        return []

    def splitlines(self, keepends=None): # real signature unknown; restored from __doc__
        """
        S.splitlines([keepends]) -> list of strings
        
        Return a list of the lines in S, breaking at line boundaries.
        Line breaks are not included in the resulting list unless keepends
        is given and true.
        """
        return []

    def startswith(self, prefix, start=None, end=None): # real signature unknown; restored from __doc__
        """ 指定以什么开始
        S.startswith(prefix[, start[, end]]) -> bool
        
        Return True if S starts with the specified prefix, False otherwise.
        With optional start, test S beginning at that position.
        With optional end, stop comparing S at that position.
        prefix can also be a tuple of strings to try.
        """
        return False

    def strip(self, chars=None): # real signature unknown; restored from __doc__
        """  去除两端空格
        S.strip([chars]) -> str
        
        Return a copy of the string S with leading and trailing
        whitespace removed.
        If chars is given and not None, remove characters in chars instead.
        """
        return ""

    def swapcase(self): # real signature unknown; restored from __doc__
        """ 大写转小写小写转大写
        S.swapcase() -> str
        
        Return a copy of S with uppercase characters converted to lowercase
        and vice versa.
        """
        return ""

    def title(self): # real signature unknown; restored from __doc__
        """
        S.title() -> str
        
        Return a titlecased version of S, i.e. words start with title case
        characters, all remaining cased characters have lower case.
        """
        return ""

    def translate(self, table): # real signature unknown; restored from __doc__
        """


　　　　转换，需要先做一个对应表，最后一个表示删除字符集合
　　　　intab = "aeiou"
　　　　outtab = "12345"
　　　　trantab = maketrans(intab, outtab)
　　　　str = "this is string example....wow!!!"print str.translate(trantab, 'xm')




        S.translate(table) -> str
        
        Return a copy of the string S in which each character has been mapped
        through the given translation table. The table must implement
        lookup/indexing via __getitem__, for instance a dictionary or list,
        mapping Unicode ordinals to Unicode ordinals, strings, or None. If
        this operation raises LookupError, the character is left untouched.
        Characters mapped to None are deleted.
        """
        return ""

    def upper(self): # real signature unknown; restored from __doc__
        """ 大写显示
        S.upper() -> str
        
        Return a copy of S converted to uppercase.
        """
        return ""

    def zfill(self, width): # real signature unknown; restored from __doc__
        """ 方法返回指定长度的字符串，原字符串右对齐，前面填充0。
        S.zfill(width) -> str
        
        Pad a numeric string S with zeros on the left, to fill a field
        of the specified width. The string S is never truncated.
        """
        return ""

    def __add__(self, *args, **kwargs): # real signature unknown
        """ Return self+value. """
        pass

    def __contains__(self, *args, **kwargs): # real signature unknown
        """ Return key in self. """
        pass

    def __eq__(self, *args, **kwargs): # real signature unknown
        """ Return self==value. """
        pass

    def __format__(self, format_spec): # real signature unknown; restored from __doc__
        """
        S.__format__(format_spec) -> str
        
        Return a formatted version of S as described by format_spec.
        """
        return ""

    def __getattribute__(self, *args, **kwargs): # real signature unknown
        """ Return getattr(self, name). """
        pass

    def __getitem__(self, *args, **kwargs): # real signature unknown
        """ Return self[key]. """
        pass

    def __getnewargs__(self, *args, **kwargs): # real signature unknown
        pass

    def __ge__(self, *args, **kwargs): # real signature unknown
        """ Return self>=value. """
        pass

    def __gt__(self, *args, **kwargs): # real signature unknown
        """ Return self>value. """
        pass

    def __hash__(self, *args, **kwargs): # real signature unknown
        """ Return hash(self). """
        pass

    def __init__(self, value='', encoding=None, errors='strict'): # known special case of str.__init__
        """
        str(object='') -> str
        str(bytes_or_buffer[, encoding[, errors]]) -> str
        
        Create a new string object from the given object. If encoding or
        errors is specified, then the object must expose a data buffer
        that will be decoded using the given encoding and error handler.
        Otherwise, returns the result of object.__str__() (if defined)
        or repr(object).
        encoding defaults to sys.getdefaultencoding().
        errors defaults to 'strict'.
        # (copied from class doc)
        """
        pass

    def __iter__(self, *args, **kwargs): # real signature unknown
        """ Implement iter(self). """
        pass

    def __len__(self, *args, **kwargs): # real signature unknown
        """ Return len(self). """
        pass

    def __le__(self, *args, **kwargs): # real signature unknown
        """ Return self<=value. """
        pass

    def __lt__(self, *args, **kwargs): # real signature unknown
        """ Return self<value. """
        pass

    def __mod__(self, *args, **kwargs): # real signature unknown
        """ Return self%value. """
        pass

    def __mul__(self, *args, **kwargs): # real signature unknown
        """ Return self*value.n """
        pass

    @staticmethod # known case of __new__
    def __new__(*args, **kwargs): # real signature unknown
        """ Create and return a new object.  See help(type) for accurate signature. """
        pass

    def __ne__(self, *args, **kwargs): # real signature unknown
        """ Return self!=value. """
        pass

    def __repr__(self, *args, **kwargs): # real signature unknown
        """ Return repr(self). """
        pass

    def __rmod__(self, *args, **kwargs): # real signature unknown
        """ Return value%self. """
        pass

    def __rmul__(self, *args, **kwargs): # real signature unknown
        """ Return self*value. """
        pass

    def __sizeof__(self): # real signature unknown; restored from __doc__
        """ S.__sizeof__() -> size of S in memory, in bytes """
        pass

    def __str__(self, *args, **kwargs): # real signature unknown
        """ Return str(self). """
        pass

　　1 可以去除两端空格
   2 可以去除末尾

   3 可以去除 空行
   4 可以传如参数，比如
　　　　n = “hello”
       s = n.strip（“o”）
　　　　print s  结果是  = ‘hell’

4、列表

创建列表：

name_list = ['alex', 'seven', 'eric']
或
name_list ＝ list(['alex', 'seven', 'eric'])

基本操作：

• 索引
• 切片
• 追加
• 删除
• 长度
• 切片
• 循环
• 包含

class list(object):
    """
    list() -> new empty list
    list(iterable) -> new list initialized from iterable's items
    """
    def append(self, p_object): # real signature unknown; restored from __doc__
        """  添加 元素
　　　　　　L.append(object) -> None -- append object to end """
        pass

    def clear(self): # real signature unknown; restored from __doc__
        """  清空元素
　　　　L.clear() -> None -- remove all items from L """
        pass

    def copy(self): # real signature unknown; restored from __doc__
        """ 浅copy  L.copy() -> list -- a shallow copy of L """
        return []

    def count(self, value): # real signature unknown; restored from __doc__
        """ 匹配 value的个数   L.count(value) -> integer -- return number of occurrences of value """
        return 0

    def extend(self, iterable): # real signature unknown; restored from __doc__
        """ 拼接两个列表   L.extend(iterable) -> None -- extend list by appending elements from the iterable """
        pass

    def index(self, value, start=None, stop=None): # real signature unknown; restored from __doc__
        """ 返回 某个value 的索引
        L.index(value, [start, [stop]]) -> integer -- return first index of value.
        Raises ValueError if the value is not present.
        """
        return 0

    def insert(self, index, p_object): # real signature unknown; restored from __doc__
        """ 指定索引位置处添加元素 L.insert(index, object) -- insert object before index """
        pass

    def pop(self, index=None): # real signature unknown; restored from __doc__
        """  删除结尾的元素
        L.pop([index]) -> item -- remove and return item at index (default last).
        Raises IndexError if list is empty or index is out of range.
        """
        pass

    def remove(self, value): # real signature unknown; restored from __doc__
        """ 移除 从左测匹配的第一个元素
        L.remove(value) -> None -- remove first occurrence of value.
        Raises ValueError if the value is not present.
        """
        pass

    def reverse(self): # real signature unknown; restored from __doc__
        """ 反转列表  L.reverse() -- reverse *IN PLACE* """
        pass

    def sort(self, key=None, reverse=False): # real signature unknown; restored from __doc__
        """ 排序 但是int str不行  L.sort(key=None, reverse=False) -> None -- stable sort *IN PLACE* """
        pass

    def __add__(self, *args, **kwargs): # real signature unknown
        """ Return self+value. """
        pass

    def __contains__(self, *args, **kwargs): # real signature unknown
        """ Return key in self. """
        pass

    def __delitem__(self, *args, **kwargs): # real signature unknown
        """ Delete self[key]. """
        pass

    def __eq__(self, *args, **kwargs): # real signature unknown
        """ Return self==value. """
        pass

    def __getattribute__(self, *args, **kwargs): # real signature unknown
        """ Return getattr(self, name). """
        pass

    def __getitem__(self, y): # real signature unknown; restored from __doc__
        """ x.__getitem__(y) <==> x[y] """
        pass

    def __ge__(self, *args, **kwargs): # real signature unknown
        """ Return self>=value. """
        pass

    def __gt__(self, *args, **kwargs): # real signature unknown
        """ Return self>value. """
        pass

    def __iadd__(self, *args, **kwargs): # real signature unknown
        """ Implement self+=value. """
        pass

    def __imul__(self, *args, **kwargs): # real signature unknown
        """ Implement self*=value. """
        pass

    def __init__(self, seq=()): # known special case of list.__init__
        """
        list() -> new empty list
        list(iterable) -> new list initialized from iterable's items
        # (copied from class doc)
        """
        pass

    def __iter__(self, *args, **kwargs): # real signature unknown
        """ Implement iter(self). """
        pass

    def __len__(self, *args, **kwargs): # real signature unknown
        """ Return len(self). """
        pass

    def __le__(self, *args, **kwargs): # real signature unknown
        """ Return self<=value. """
        pass

    def __lt__(self, *args, **kwargs): # real signature unknown
        """ Return self<value. """
        pass

    def __mul__(self, *args, **kwargs): # real signature unknown
        """ Return self*value.n """
        pass

    @staticmethod # known case of __new__
    def __new__(*args, **kwargs): # real signature unknown
        """ Create and return a new object.  See help(type) for accurate signature. """
        pass

    def __ne__(self, *args, **kwargs): # real signature unknown
        """ Return self!=value. """
        pass

    def __repr__(self, *args, **kwargs): # real signature unknown
        """ Return repr(self). """
        pass

    def __reversed__(self): # real signature unknown; restored from __doc__
        """ L.__reversed__() -- return a reverse iterator over the list """
        pass

    def __rmul__(self, *args, **kwargs): # real signature unknown
        """ Return self*value. """
        pass

    def __setitem__(self, *args, **kwargs): # real signature unknown
        """ Set self[key] to value. """
        pass

    def __sizeof__(self): # real signature unknown; restored from __doc__
        """ L.__sizeof__() -- size of L in memory, in bytes """
        pass

    __hash__ = None

示例：

######　列表　##########

#!/usr/bin/env python
# _*_ coding:utf-8 _*_
__author__ = 'liujianzuo'


lis=[1,2,3,'alex']
cc=[5,5]
print(lis.count("alex"))
lis.extend(cc)
print(lis)

name_list = ["eirc", "alex", 'tony']
"""
# 索引
print(name_list[0])
# 切片
print(name_list[0:2])
# len
print(name_list[2:len(name_list)])
# for
for i in name_list:
    print(i)


#join 方法，拼接字符串
li = ["alex","eric"]
name = "li jie"
ss = "_".join(li)
s = "_".join(name)
print(s,ss)


"""
# 列表内部提供的其他功能
# append后追加
name_list.append('seven')
name_list.append('seven')
name_list.append('seven')
print(name_list)
# 元素出现的次数
print(name_list.count('seven'))
# iterable，可迭代的
temp = [111,22,33,44]
# 扩展，批量添加
name_list.extend(temp)
print(name_list)
# 获取指定元素的索引位置
print(name_list.index('alex'))
# 向指定索引位置插入数据
name_list.insert(1, 'SB')
print(name_list)
# 在原列表中移除掉最后一个元素，并将其赋值给 a1
a1 = name_list.pop()
print(name_list)
print(a1)
# 移除某个元素
name_list.remove('seven')
print(name_list)
# 翻转
name_list.reverse()
print(name_list)

#　删除指定索引位置
print(name_list)
del name_list[1:3]
print(name_list)