Python一路走来 - python基础 数据类型

对于Python，一切事物都是对象，对象基于类创建

Python数据类型

python主要的数据类型主要包括以下几种类型：

(1) 数字型

(2) 字符串

(3) 列表

(4) 元组

(5) 字典

(6) bool型

 

数字型

一、整数

如： 18、73、84

每一个整数都具备如下功能：

class int(object):
    """
    int(x=0) -> int or long
    int(x, base=10) -> int or long
    
    Convert a number or string to an integer, or return 0 if no arguments
    are given.  If x is floating point, the conversion truncates towards zero.
    If x is outside the integer range, the function returns a long instead.
    
    If x is not a number or if base is given, then x must be a string or
    Unicode object 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): 
        """ 返回表示该数字的时占用的最少位数 """
        """
        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

    def __abs__(self):
        """ 返回绝对值 """
        """ x.__abs__() <==> abs(x) """
        pass

    def __add__(self, y):
        """ x.__add__(y) <==> x+y """
        pass

    def __and__(self, y):
        """ x.__and__(y) <==> x&y """
        pass

    def __cmp__(self, y): 
        """ 比较两个数大小 """
        """ x.__cmp__(y) <==> cmp(x,y) """
        pass

    def __coerce__(self, y):
        """ 强制生成一个元组 """ 
        """ x.__coerce__(y) <==> coerce(x, y) """
        pass

    def __divmod__(self, y): 
        """ 相除，得到商和余数组成的元组 """ 
        """ x.__divmod__(y) <==> divmod(x, y) """
        pass

    def __div__(self, y): 
        """ x.__div__(y) <==> x/y """
        pass

    def __float__(self): 
        """ 转换为浮点类型 """ 
        """ x.__float__() <==> float(x) """
        pass

    def __floordiv__(self, y): 
        """ x.__floordiv__(y) <==> x//y """
        pass

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

    def __getattribute__(self, name): 
        """ x.__getattribute__('name') <==> x.name """
        pass

    def __getnewargs__(self, *args, **kwargs): # real signature unknown
        """ 内部调用 __new__方法或创建对象时传入参数使用 """ 
        pass

    def __hash__(self): 
        """如果对象object为哈希表类型，返回对象object的哈希值。哈希值为整数。在字典查找中，哈希值用于快速比较字典的键。两个数值如果相等，则哈希值也相等。"""
        """ x.__hash__() <==> hash(x) """
        pass

    def __hex__(self): 
        """ 返回当前数的 十六进制 表示 """ 
        """ x.__hex__() <==> hex(x) """
        pass

    def __index__(self): 
        """ 用于切片，数字无意义 """
        """ x[y:z] <==> x[y.__index__():z.__index__()] """
        pass

    def __init__(self, x, base=10): # known special case of int.__init__
        """ 构造方法，执行 x = 123 或 x = int(10) 时，自动调用，暂时忽略 """ 
        """
        int(x=0) -> int or long
        int(x, base=10) -> int or long
        
        Convert a number or string to an integer, or return 0 if no arguments
        are given.  If x is floating point, the conversion truncates towards zero.
        If x is outside the integer range, the function returns a long instead.
        
        If x is not a number or if base is given, then x must be a string or
        Unicode object 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): 
        """ 转换为整数 """ 
        """ x.__int__() <==> int(x) """
        pass

    def __invert__(self): 
        """ x.__invert__() <==> ~x """
        pass

    def __long__(self): 
        """ 转换为长整数 """ 
        """ x.__long__() <==> long(x) """
        pass

    def __lshift__(self, y): 
        """ x.__lshift__(y) <==> x<<y """
        pass

    def __mod__(self, y): 
        """ x.__mod__(y) <==> x%y """
        pass

    def __mul__(self, y): 
        """ x.__mul__(y) <==> x*y """
        pass

    def __neg__(self): 
        """ x.__neg__() <==> -x """
        pass

    @staticmethod # known case of __new__
    def __new__(S, *more): 
        """ T.__new__(S, ...) -> a new object with type S, a subtype of T """
        pass

    def __nonzero__(self): 
        """ x.__nonzero__() <==> x != 0 """
        pass

    def __oct__(self): 
        """ 返回改值的 八进制 表示 """ 
        """ x.__oct__() <==> oct(x) """
        pass

    def __or__(self, y): 
        """ x.__or__(y) <==> x|y """
        pass

    def __pos__(self): 
        """ x.__pos__() <==> +x """
        pass

    def __pow__(self, y, z=None): 
        """ 幂，次方 """ 
        """ x.__pow__(y[, z]) <==> pow(x, y[, z]) """
        pass

    def __radd__(self, y): 
        """ x.__radd__(y) <==> y+x """
        pass

    def __rand__(self, y): 
        """ x.__rand__(y) <==> y&x """
        pass

    def __rdivmod__(self, y): 
        """ x.__rdivmod__(y) <==> divmod(y, x) """
        pass

    def __rdiv__(self, y): 
        """ x.__rdiv__(y) <==> y/x """
        pass

    def __repr__(self): 
        """转化为解释器可读取的形式 """
        """ x.__repr__() <==> repr(x) """
        pass

    def __str__(self): 
        """转换为人阅读的形式，如果没有适于人阅读的解释形式的话，则返回解释器课阅读的形式"""
        """ x.__str__() <==> str(x) """
        pass

    def __rfloordiv__(self, y): 
        """ x.__rfloordiv__(y) <==> y//x """
        pass

    def __rlshift__(self, y): 
        """ x.__rlshift__(y) <==> y<<x """
        pass

    def __rmod__(self, y): 
        """ x.__rmod__(y) <==> y%x """
        pass

    def __rmul__(self, y): 
        """ x.__rmul__(y) <==> y*x """
        pass

    def __ror__(self, y): 
        """ x.__ror__(y) <==> y|x """
        pass

    def __rpow__(self, x, z=None): 
        """ y.__rpow__(x[, z]) <==> pow(x, y[, z]) """
        pass

    def __rrshift__(self, y): 
        """ x.__rrshift__(y) <==> y>>x """
        pass

    def __rshift__(self, y): 
        """ x.__rshift__(y) <==> x>>y """
        pass

    def __rsub__(self, y): 
        """ x.__rsub__(y) <==> y-x """
        pass

    def __rtruediv__(self, y): 
        """ x.__rtruediv__(y) <==> y/x """
        pass

    def __rxor__(self, y): 
        """ x.__rxor__(y) <==> y^x """
        pass

    def __sub__(self, y): 
        """ x.__sub__(y) <==> x-y """
        pass

    def __truediv__(self, y): 
        """ x.__truediv__(y) <==> x/y """
        pass

    def __trunc__(self, *args, **kwargs): 
        """ 返回数值被截取为整形的值，在整形中无意义 """
        pass

    def __xor__(self, y): 
        """ x.__xor__(y) <==> x^y """
        pass

    denominator = property(lambda self: object(), lambda self, v: None, lambda self: None)  # default
    """ 分母 = 1 """
    """the denominator of a rational number in lowest terms"""

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

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

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

二、长整型

可能如：2147483649、9223372036854775807

每个长整型都具备如下功能：

class long(object):
    """
    long(x=0) -> long
    long(x, base=10) -> long
    
    Convert a number or string to a long integer, or return 0L if no arguments
    are given.  If x is floating point, the conversion truncates towards zero.
    
    If x is not a number or if base is given, then x must be a string or
    Unicode object 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)
    4L
    """
    def bit_length(self): # real signature unknown; restored from __doc__
        """
        long.bit_length() -> int or long
        
        Number of bits necessary to represent self in binary.
        >>> bin(37L)
        '0b100101'
        >>> (37L).bit_length()
        6
        """
        return 0

    def conjugate(self, *args, **kwargs): # real signature unknown
        """ Returns self, the complex conjugate of any long. """
        pass

    def __abs__(self): # real signature unknown; restored from __doc__
        """ x.__abs__() <==> abs(x) """
        pass

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

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

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

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

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

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

    def __float__(self): # real signature unknown; restored from __doc__
        """ x.__float__() <==> float(x) """
        pass

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

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

    def __getattribute__(self, name): # real signature unknown; restored from __doc__
        """ x.__getattribute__('name') <==> x.name """
        pass

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

    def __hash__(self): # real signature unknown; restored from __doc__
        """ x.__hash__() <==> hash(x) """
        pass

    def __hex__(self): # real signature unknown; restored from __doc__
        """ x.__hex__() <==> hex(x) """
        pass

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

    def __init__(self, x=0): # real signature unknown; restored from __doc__
        pass

    def __int__(self): # real signature unknown; restored from __doc__
        """ x.__int__() <==> int(x) """
        pass

    def __invert__(self): # real signature unknown; restored from __doc__
        """ x.__invert__() <==> ~x """
        pass

    def __long__(self): # real signature unknown; restored from __doc__
        """ x.__long__() <==> long(x) """
        pass

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

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

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

    def __neg__(self): # real signature unknown; restored from __doc__
        """ x.__neg__() <==> -x """
        pass

    @staticmethod # known case of __new__
    def __new__(S, *more): # real signature unknown; restored from __doc__
        """ T.__new__(S, ...) -> a new object with type S, a subtype of T """
        pass

    def __nonzero__(self): # real signature unknown; restored from __doc__
        """ x.__nonzero__() <==> x != 0 """
        pass

    def __oct__(self): # real signature unknown; restored from __doc__
        """ x.__oct__() <==> oct(x) """
        pass

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

    def __pos__(self): # real signature unknown; restored from __doc__
        """ x.__pos__() <==> +x """
        pass

    def __pow__(self, y, z=None): # real signature unknown; restored from __doc__
        """ x.__pow__(y[, z]) <==> pow(x, y[, z]) """
        pass

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

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

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

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

    def __repr__(self): # real signature unknown; restored from __doc__
        """ x.__repr__() <==> repr(x) """
        pass

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

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

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

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

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

    def __rpow__(self, x, z=None): # real signature unknown; restored from __doc__
        """ y.__rpow__(x[, z]) <==> pow(x, y[, z]) """
        pass

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

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

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

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

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

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

    def __str__(self): # real signature unknown; restored from __doc__
        """ x.__str__() <==> str(x) """
        pass

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

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

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

    def __xor__(self, y): # real signature unknown; restored from __doc__
        """ x.__xor__(y) <==> x^y """
        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"""
Long

三、浮点型

如：3.14、2.88

每个浮点型都具备如下功能：

class float(object):
    """
    float(x) -> floating point number
    
    Convert a string or number to a floating point number, if possible.
    """
    def as_integer_ratio(self):   
        """ 获取改值的最简比 """
        """
        float.as_integer_ratio() -> (int, int)

        Return a pair of integers, whose ratio is exactly equal to the original
        float and with a positive denominator.
        Raise OverflowError on infinities and a ValueError on NaNs.

        >>> (10.0).as_integer_ratio()
        (10, 1)
        >>> (0.0).as_integer_ratio()
        (0, 1)
        >>> (-.25).as_integer_ratio()
        (-1, 4)
        """
        pass

    def conjugate(self, *args, **kwargs): # real signature unknown
        """ Return self, the complex conjugate of any float. """
        pass

    def fromhex(self, string):   
        """ 将十六进制字符串转换成浮点型 """
        """
        float.fromhex(string) -> float
        
        Create a floating-point number from a hexadecimal string.
        >>> float.fromhex('0x1.ffffp10')
        2047.984375
        >>> float.fromhex('-0x1p-1074')
        -4.9406564584124654e-324
        """
        return 0.0

    def hex(self):   
        """ 返回当前值的 16 进制表示 """
        """
        float.hex() -> string
        
        Return a hexadecimal representation of a floating-point number.
        >>> (-0.1).hex()
        '-0x1.999999999999ap-4'
        >>> 3.14159.hex()
        '0x1.921f9f01b866ep+1'
        """
        return ""

    def is_integer(self, *args, **kwargs): # real signature unknown
        """ Return True if the float is an integer. """
        pass

    def __abs__(self):   
        """ x.__abs__() <==> abs(x) """
        pass

    def __add__(self, y):   
        """ x.__add__(y) <==> x+y """
        pass

    def __coerce__(self, y):   
        """ x.__coerce__(y) <==> coerce(x, y) """
        pass

    def __divmod__(self, y):   
        """ x.__divmod__(y) <==> divmod(x, y) """
        pass

    def __div__(self, y):   
        """ x.__div__(y) <==> x/y """
        pass

    def __eq__(self, y):   
        """ x.__eq__(y) <==> x==y """
        pass

    def __float__(self):   
        """ x.__float__() <==> float(x) """
        pass

    def __floordiv__(self, y):   
        """ x.__floordiv__(y) <==> x//y """
        pass

    def __format__(self, format_spec):   
        """
        float.__format__(format_spec) -> string
        
        Formats the float according to format_spec.
        """
        return ""

    def __getattribute__(self, name):   
        """ x.__getattribute__('name') <==> x.name """
        pass

    def __getformat__(self, typestr):   
        """
        float.__getformat__(typestr) -> string
        
        You probably don't want to use this function.  It exists mainly to be
        used in Python's test suite.
        
        typestr must be 'double' or 'float'.  This function returns whichever of
        'unknown', 'IEEE, big-endian' or 'IEEE, little-endian' best describes the
        format of floating point numbers used by the C type named by typestr.
        """
        return ""

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

    def __ge__(self, y):   
        """ x.__ge__(y) <==> x>=y """
        pass

    def __gt__(self, y):   
        """ x.__gt__(y) <==> x>y """
        pass

    def __hash__(self):   
        """ x.__hash__() <==> hash(x) """
        pass

    def __init__(self, x):   
        pass

    def __int__(self):   
        """ x.__int__() <==> int(x) """
        pass

    def __le__(self, y):   
        """ x.__le__(y) <==> x<=y """
        pass

    def __long__(self):   
        """ x.__long__() <==> long(x) """
        pass

    def __lt__(self, y):   
        """ x.__lt__(y) <==> x<y """
        pass

    def __mod__(self, y):   
        """ x.__mod__(y) <==> x%y """
        pass

    def __mul__(self, y):   
        """ x.__mul__(y) <==> x*y """
        pass

    def __neg__(self):   
        """ x.__neg__() <==> -x """
        pass

    @staticmethod # known case of __new__
    def __new__(S, *more):   
        """ T.__new__(S, ...) -> a new object with type S, a subtype of T """
        pass

    def __ne__(self, y):   
        """ x.__ne__(y) <==> x!=y """
        pass

    def __nonzero__(self):   
        """ x.__nonzero__() <==> x != 0 """
        pass

    def __pos__(self):   
        """ x.__pos__() <==> +x """
        pass

    def __pow__(self, y, z=None):   
        """ x.__pow__(y[, z]) <==> pow(x, y[, z]) """
        pass

    def __radd__(self, y):   
        """ x.__radd__(y) <==> y+x """
        pass

    def __rdivmod__(self, y):   
        """ x.__rdivmod__(y) <==> divmod(y, x) """
        pass

    def __rdiv__(self, y):   
        """ x.__rdiv__(y) <==> y/x """
        pass

    def __repr__(self):   
        """ x.__repr__() <==> repr(x) """
        pass

    def __rfloordiv__(self, y):   
        """ x.__rfloordiv__(y) <==> y//x """
        pass

    def __rmod__(self, y):   
        """ x.__rmod__(y) <==> y%x """
        pass

    def __rmul__(self, y):   
        """ x.__rmul__(y) <==> y*x """
        pass

    def __rpow__(self, x, z=None):   
        """ y.__rpow__(x[, z]) <==> pow(x, y[, z]) """
        pass

    def __rsub__(self, y):   
        """ x.__rsub__(y) <==> y-x """
        pass

    def __rtruediv__(self, y):   
        """ x.__rtruediv__(y) <==> y/x """
        pass

    def __setformat__(self, typestr, fmt):   
        """
        float.__setformat__(typestr, fmt) -> None
        
        You probably don't want to use this function.  It exists mainly to be
        used in Python's test suite.
        
        typestr must be 'double' or 'float'.  fmt must be one of 'unknown',
        'IEEE, big-endian' or 'IEEE, little-endian', and in addition can only be
        one of the latter two if it appears to match the underlying C reality.
        
        Override the automatic determination of C-level floating point type.
        This affects how floats are converted to and from binary strings.
        """
        pass

    def __str__(self):   
        """ x.__str__() <==> str(x) """
        pass

    def __sub__(self, y):   
        """ x.__sub__(y) <==> x-y """
        pass

    def __truediv__(self, y):   
        """ x.__truediv__(y) <==> x/y """
        pass

    def __trunc__(self, *args, **kwargs): # real signature unknown
        """ Return the Integral closest to x between 0 and x. """
        pass

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

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

字符串

如：'gary'、'leon

每个字符串都具备如下功能：

class str(basestring):
    """
    str(object='') -> string
    
    Return a nice string representation of the object.
    If the argument is a string, the return value is the same object.
    """
    def capitalize(self):  
        """ 首字母变大写 """
        """
        S.capitalize() -> string
        
        Return a copy of the string S with only its first character
        capitalized.
        """
        return ""

    def center(self, width, fillchar=None):  
        """ 内容居中，width：总长度；fillchar：空白处填充内容，默认无 """
        """
        S.center(width[, fillchar]) -> string
        
        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):  
        """ 子序列个数 """
        """
        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 decode(self, encoding=None, errors=None):  
        """ 解码 """
        """
        S.decode([encoding[,errors]]) -> object
        
        Decodes S using the codec registered for encoding. encoding defaults
        to the default encoding. errors may be given to set a different error
        handling scheme. Default is 'strict' meaning that encoding errors raise
        a UnicodeDecodeError. Other possible values are 'ignore' and 'replace'
        as well as any other name registered with codecs.register_error that is
        able to handle UnicodeDecodeErrors.
        """
        return object()

    def encode(self, encoding=None, errors=None):  
        """ 编码，针对unicode """
        """
        S.encode([encoding[,errors]]) -> object
        
        Encodes S using the codec registered for encoding. encoding defaults
        to the default encoding. 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 is able to handle UnicodeEncodeErrors.
        """
        return object()

    def endswith(self, suffix, start=None, end=None):  
        """ 是否以 xxx 结束 """
        """
        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=None):  
        """ 将tab转换成空格，默认一个tab转换成8个空格 """
        """
        S.expandtabs([tabsize]) -> string
        
        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):  
        """ 寻找子序列位置，如果没找到，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
        """ 字符串格式化，动态参数，将函数式编程时细说 """
        """
        S.format(*args, **kwargs) -> string
        
        Return a formatted version of S, using substitutions from args and kwargs.
        The substitutions are identified by braces ('{' and '}').
        """
        pass

    def index(self, sub, start=None, end=None):  
        """ 子序列位置，如果没找到，报错 """
        S.index(sub [,start [,end]]) -> int
        
        Like S.find() but raise ValueError when the substring is not found.
        """
        return 0

    def isalnum(self):  
        """ 是否是字母和数字 """
        """
        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):  
        """ 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 isdigit(self):  
        """ 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 islower(self):  
        """ 是否小写 """
        """
        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 isspace(self):  
        """
        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):  
        """
        S.istitle() -> bool
        
        Return True if S is a titlecased string and there is at least one
        character in S, i.e. uppercase characters may only follow uncased
        characters and lowercase characters only cased ones. Return False
        otherwise.
        """
        return False

    def isupper(self):  
        """
        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):  
        """ 连接 """
        """
        S.join(iterable) -> string
        
        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):  
        """ 内容左对齐，右侧填充 """
        """
        S.ljust(width[, fillchar]) -> string
        
        Return S left-justified in a string of length width. Padding is
        done using the specified fill character (default is a space).
        """
        return ""

    def lower(self):  
        """ 变小写 """
        """
        S.lower() -> string
        
        Return a copy of the string S converted to lowercase.
        """
        return ""

    def lstrip(self, chars=None):  
        """ 移除左侧空白 """
        """
        S.lstrip([chars]) -> string or unicode
        
        Return a copy of the string S with leading whitespace removed.
        If chars is given and not None, remove characters in chars instead.
        If chars is unicode, S will be converted to unicode before stripping
        """
        return ""

    def partition(self, sep):  
        """ 分割，前，中，后三部分 """
        """
        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):  
        """ 替换 """
        """
        S.replace(old, new[, count]) -> string
        
        Return a copy of string 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):  
        """
        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):  
        """
        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):  
        """
        S.rjust(width[, fillchar]) -> string
        
        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):  
        """
        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=None):  
        """
        S.rsplit([sep [,maxsplit]]) -> list of strings
        
        Return a list of the words in the string 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 or is None, any whitespace string
        is a separator.
        """
        return []

    def rstrip(self, chars=None):  
        """
        S.rstrip([chars]) -> string or unicode
        
        Return a copy of the string S with trailing whitespace removed.
        If chars is given and not None, remove characters in chars instead.
        If chars is unicode, S will be converted to unicode before stripping
        """
        return ""

    def split(self, sep=None, maxsplit=None):  
        """ 分割， maxsplit最多分割几次 """
        """
        S.split([sep [,maxsplit]]) -> list of strings
        
        Return a list of the words in the string 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=False):  
        """ 根据换行分割 """
        """
        S.splitlines(keepends=False) -> 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):  
        """ 是否起始 """
        """
        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):  
        """ 移除两段空白 """
        """
        S.strip([chars]) -> string or unicode
        
        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.
        If chars is unicode, S will be converted to unicode before stripping
        """
        return ""

    def swapcase(self):  
        """ 大写变小写，小写变大写 """
        """
        S.swapcase() -> string
        
        Return a copy of the string S with uppercase characters
        converted to lowercase and vice versa.
        """
        return ""

    def title(self):  
        """
        S.title() -> string
        
        Return a titlecased version of S, i.e. words start with uppercase
        characters, all remaining cased characters have lowercase.
        """
        return ""

    def translate(self, table, deletechars=None):  
        """
        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 [,deletechars]) -> string
        
        Return a copy of the string S, where all characters occurring
        in the optional argument deletechars are removed, and the
        remaining characters have been mapped through the given
        translation table, which must be a string of length 256 or None.
        If the table argument is None, no translation is applied and
        the operation simply removes the characters in deletechars.
        """
        return ""

    def upper(self):  
        """
        S.upper() -> string
        
        Return a copy of the string S converted to uppercase.
        """
        return ""

    def zfill(self, width):  
        """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) -> string
        
        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 _formatter_field_name_split(self, *args, **kwargs): # real signature unknown
        pass

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

    def __add__(self, y):  
        """ x.__add__(y) <==> x+y """
        pass

    def __contains__(self, y):  
        """ x.__contains__(y) <==> y in x """
        pass

    def __eq__(self, y):  
        """ x.__eq__(y) <==> x==y """
        pass

    def __format__(self, format_spec):  
        """
        S.__format__(format_spec) -> string
        
        Return a formatted version of S as described by format_spec.
        """
        return ""

    def __getattribute__(self, name):  
        """ x.__getattribute__('name') <==> x.name """
        pass

    def __getitem__(self, y):  
        """ x.__getitem__(y) <==> x[y] """
        pass

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

    def __getslice__(self, i, j):  
        """
        x.__getslice__(i, j) <==> x[i:j]
                   
                   Use of negative indices is not supported.
        """
        pass

    def __ge__(self, y):  
        """ x.__ge__(y) <==> x>=y """
        pass

    def __gt__(self, y):  
        """ x.__gt__(y) <==> x>y """
        pass

    def __hash__(self):  
        """ x.__hash__() <==> hash(x) """
        pass

    def __init__(self, string=''): # known special case of str.__init__
        """
        str(object='') -> string
        
        Return a nice string representation of the object.
        If the argument is a string, the return value is the same object.
        # (copied from class doc)
        """
        pass

    def __len__(self):  
        """ x.__len__() <==> len(x) """
        pass

    def __le__(self, y):  
        """ x.__le__(y) <==> x<=y """
        pass

    def __lt__(self, y):  
        """ x.__lt__(y) <==> x<y """
        pass

    def __mod__(self, y):  
        """ x.__mod__(y) <==> x%y """
        pass

    def __mul__(self, n):  
        """ x.__mul__(n) <==> x*n """
        pass

    @staticmethod # known case of __new__
    def __new__(S, *more):  
        """ T.__new__(S, ...) -> a new object with type S, a subtype of T """
        pass

    def __ne__(self, y):  
        """ x.__ne__(y) <==> x!=y """
        pass

    def __repr__(self):  
        """ x.__repr__() <==> repr(x) """
        pass

    def __rmod__(self, y):  
        """ x.__rmod__(y) <==> y%x """
        pass

    def __rmul__(self, n):  
        """ x.__rmul__(n) <==> n*x """
        pass

    def __sizeof__(self):  
        """ S.__sizeof__() -> size of S in memory, in bytes """
        pass

    def __str__(self):  
        """ x.__str__() <==> str(x) """
        pass

str
str

常用例子:

字符串内建函数

capitalize  : 将字符串的首字母大写，其它均小写

[python] view plain copy
 
 print?
  1. >>> a = 'aBCdEF'  
  2. >>> a.capitalize()  
  3. 'Abcdef'  

casefold : 此功能与lower功能类似,将字符串转换为小写

lower : 将所有字符转换为小写

center rjust  ljust : 根据显示的长度中间对齐、左对齐、右对齐，不足的部分根据指定内容填充,默认为空格

[python] view plain copy
 
 print?
  1. >>>> b 'Hello sOrlD'   
  2. >>> b.center(20)   
  3. ' Hello sOrlD '  
  4.  >>> b.center(20,'*')  
  5.  '****Hello sOrlD*****'   
  6. >>> b.ljust(20,'*')  
  7.  'Hello sOrlD*********'   
  8. >>> b.rjust(20,'*')   
  9. '*********Hello sOrlD'  

count : 统计字符串中包含子串的个数

 

[python] view plain copy
 
 print?
  1. >>> a = 'aaAAbbBB'  
  2. >>> a.count('a')  
  3. 2  

lstrip 、 rstrip、  strip :  去除字符串左边空格  右边空格  两边空格

[python] view plain copy
 
 print?
  1. >>> a  
  2. '   abc   '  
  3. >>> a.strip()  
  4. 'abc'  
  5. >>> a.lstrip()  
  6. 'abc   '  
  7. >>> a.rstrip()  
  8. '   abc'  

 

startswith  endswith 是否已制定子串开始  是否已制定子串结尾

[python] view plain copy
 
 print?
  1. >>> a='abc1234def'  
  2. >>> a.startswith('abc')  
  3. True  
  4. >>> a.endswith('def')  
  5. True  

translate  用指定的字符串替换,该内置函数在2.x与3.x中使用方法有一定区别

3.x

[python] view plain copy
 
 print?
  1. >>> a = '12345'  
  2. >>> b = 'abcde'  
  3. >>> source = 'aAAbc123d'  
  4. >>> source.translate(source.maketrans(b,a))  
  5. '1AA231234'  

split  rsplit  按照指定字符进行分割

[python] view plain copy
 
 print?
  1. >>> a = '123e456e789'  
  2. >>> a.split('e')  
  3. ['123', '456', '789']  
  4. >>> a.rsplit('e')  
  5. ['123', '456', '789']  

splitlines 按照行分隔，返回一个包含各行作为元素的列表

[python] view plain copy
 
 print?
  1. >>> a = '''''123 
  2. 456 
  3. 789 
  4. '''  
  5. >>> a  
  6. '123\n456\n789\n'  
  7. >>> a.splitlines()  
  8. ['123', '456', '789']  

find  rfind  分别表示从左边、右边开始搜索指定的字符串子串,返回从0开始的下标值，找不到返回-1

[python] view plain copy
 
 print?
  1. >>> a  
  2. '123\n456\n789\n'  
  3. >>> a.find('a')  
  4. -1  
  5. >>> a.find('\n')  
  6. 3  
  7. >>> a.rfind('\n')  
  8. 11  

index  rindex 功能与上面的find类似，只是找不到的时候返回错误
zfill  指定一个宽度，不足的左边补0

[python] view plain copy
 
 print?
  1. >>> a = 'abcd'  
  2. >>> a.zfill(10)  
  3. '000000abcd'  

upper  lower 分别表示转换字母为大 、小 写
join 用指定字符串分隔

[python] view plain copy
 
 print?
  1. >>> a  
  2. 'abcd'  
  3. >>> ' '.join(a)  
  4. 'a b c d'  
  5. >>> '_'.join(a)  
  6. 'a_b_c_d'  

replace 替换指定字符串为子串

[python] view plain copy
 
 print?
  1. >>> a = '123abc123'  
  2. >>> a.replace('abc','ABC')  
  3. '123ABC123'  

swapcase 将字符串的大小写反转，大写变小写，小写变大写

[python] view plain copy
 
 print?
  1. >>> a='abcABC'  
  2. >>> a.swapcase()  
  3. 'ABCabc''  

 format  格式化字符串，返回格式化后的内容

 

[python] view plain copy
 
 print?
  1. >>> s = 'i am {0}, age is {1},sex is {2}'  
  2. >>> s.format('aaaa',12,'F')  
  3. 'i am aaaa, age is 12,sex is F'  
  4.   
  5. >>> d = 'i am {name},age is {age}, sex is {sex}'  
  6. >>> d.format(name='sss',age=12,sex='F')  
  7. 'i am sss,age is 12, sex is F'  


 

判断属性：

isnum 是否是数字

isalpha  如果 string 至少有一个字符并且所有字符都是字母则返回 True,否则返回 False

isdecimal  如果 string 只包含十进制数字则返回 True 否则返回 False

istitle  是否是标题(标题的每个单词首字母大写),是返回True

isupper   是否都是大写字母

islower   是否都是小写字母

isdigit  如果 string 只包含数字则返回 True 否则返回 False.

isalnum 如果 string 至少有一个字符并且所有字符都是字母或数字则返回 True,否则返回 False

字符串运算符

+       字符串连接                                                                                   a + b 输出结果： HelloPython
*        重复输出字符串                                                                             a*2 输出结果：HelloHello
[]       通过索引获取字符串中字符                                                          a[1] 输出结果 e
[ : ]    截取字符串中的一部分                                                               a[1:4] 输出结果 ell
in      成员运算符 - 如果字符串中包含给定的字符返回 True                  H in a 输出结果 1
not in  成员运算符 - 如果字符串中不包含给定的字符返回 True        M not in a 输出结果 1

 

列表

python中的列表是一个具有灵活性的有序集合对象类型，与字符串不同,列表可以包含任何类型的对象、数字、字符串甚至其他列表。

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__
        """ L.append(object) -- append object to end """
        pass

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

    def extend(self, iterable): # real signature unknown; restored from __doc__
        """ L.extend(iterable) -- extend list by appending elements from the iterable """
        pass

    def index(self, value, start=None, stop=None): # real signature unknown; restored from __doc__
        """
        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__
        """ L.insert(index, object) -- insert object before index """
        pass

    def pop(self, index=None): # real signature unknown; restored from __doc__
        """
        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__
        """
        L.remove(value) -- remove first occurrence of value.
        Raises ValueError if the value is not present.
        """
        pass

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

    def sort(self, cmp=None, key=None, reverse=False): # real signature unknown; restored from __doc__
        """
        L.sort(cmp=None, key=None, reverse=False) -- stable sort *IN PLACE*;
        cmp(x, y) -> -1, 0, 1
        """
        pass

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

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

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

    def __delslice__(self, i, j): # real signature unknown; restored from __doc__
        """
        x.__delslice__(i, j) <==> del x[i:j]
                   
                   Use of negative indices is not supported.
        """
        pass

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

    def __getattribute__(self, name): # real signature unknown; restored from __doc__
        """ x.__getattribute__('name') <==> x.name """
        pass

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

    def __getslice__(self, i, j): # real signature unknown; restored from __doc__
        """
        x.__getslice__(i, j) <==> x[i:j]
                   
                   Use of negative indices is not supported.
        """
        pass

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

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

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

    def __imul__(self, y): # real signature unknown; restored from __doc__
        """ x.__imul__(y) <==> x*=y """
        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): # real signature unknown; restored from __doc__
        """ x.__iter__() <==> iter(x) """
        pass

    def __len__(self): # real signature unknown; restored from __doc__
        """ x.__len__() <==> len(x) """
        pass

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

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

    def __mul__(self, n): # real signature unknown; restored from __doc__
        """ x.__mul__(n) <==> x*n """
        pass

    @staticmethod # known case of __new__
    def __new__(S, *more): # real signature unknown; restored from __doc__
        """ T.__new__(S, ...) -> a new object with type S, a subtype of T """
        pass

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

    def __repr__(self): # real signature unknown; restored from __doc__
        """ x.__repr__() <==> repr(x) """
        pass

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

    def __rmul__(self, n): # real signature unknown; restored from __doc__
        """ x.__rmul__(n) <==> n*x """
        pass

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

    def __setslice__(self, i, j, y): # real signature unknown; restored from __doc__
        """
        x.__setslice__(i, j, y) <==> x[i:j]=y
                   
                   Use  of negative indices is not supported.
        """
        pass

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

    __hash__ = None
复制代码
list
列表的声明 （可以生成空列表备用）
[python] view plain copy
 
 print?
  1. >>> a=[1,2,3,4]  
  2. >>> b=list('1234')  
  3. >>> c=list(range(4))  
  4. >>> a  
  5. [1, 2, 3, 4]  
  6. >>> b  
  7. ['1', '2', '3', '4']  
  8. >>> c  
  9. [0, 1, 2, 3]  

列表常用方法

append  extend 扩展列表，追加
[python] view plain copy
 
 print?
  1. >>> a  
  2. [1, 2, 3, 4]  
  3. >>> b  
  4. ['1', '2', '3', '4']  
  5. >>> a.extend(b)  
  6. >>> a  
  7. [1, 2, 3, 4, '1', '2', '3', '4']  
  8. >>> a.append('10')  
  9. >>> a  
  10. [<span style="font-family: Arial, Helvetica, sans-serif;">1, 2, 3, 4, '1', '2', '3', '4'</span>, '10']  
clear  清空列表
[python] view plain copy
 
 print?
  1. >>> a  
  2. [1, 2, 3, 4, '1', '2', '3', '4']  
  3. >>> a.clear()  
  4. >>> a  
  5. []  
copy  拷贝列表
[python] view plain copy
 
 print?
  1. >>> a  
  2. []  
  3. >>> a = b.copy()  
  4. >>> a  
  5. ['1', '2', '3', '4']  
count  获取列表中某元素个数
[python] view plain copy
 
 print?
  1. >>> a  
  2. ['1', '2', '3', '4', '2', '4', '4', '1', '3']  
  3. >>> a.count('2')  
  4. 2  
index  获取列表中指定元素数显的第一个的位置下标
[python] view plain copy
 
 print?
  1. >>> a  
  2. ['1', '2', '3', '4', '2', '4', '4', '1', '3', '10']  
  3. >>> a.index('2')  
  4. 1  
insert(index,obj)  在指定位置index插入指定元素obj
[python] view plain copy
 
 print?
  1. >>> a.insert(2,'99')  
  2. >>> a  
  3. ['1', '2', '99', '3', '4', '2', '4', '4', '1', '3', '10']  
pop(index)   将指定位置的元素取出，并从列表中删除
[python] view plain copy
 
 print?
  1. >>> a  
  2. ['2', '3', '4', '2', '4', '4', '1', '3']  
  3. >>> a.pop(2)  
  4. '4'  
  5. >>> a  
  6. ['2', '3', '2', '4', '4', '1', '3']  
remove(value) 将指定的元素删除,,如果列表有多个指定的值,则从下标0开始的第一个元素删除
[python] view plain copy
 
 print?
  1. >>> a  
  2. ['2', '3', '2', '4', '1', '3']  
  3. >>> a.remove('2')  
  4. >>> a  
  5. ['3', '2', '4', '1', '3']  
reverse 列表元素反转 
[python] view plain copy
 
 print?
  1. >>> a  
  2. [1, 2, 3, 4, 5, 6]  
  3. >>> a.reverse()  
  4. >>> a  
  5. [6, 5, 4, 3, 2, 1]  
sort  列表元素正序排序,如果列表中所有元素的类型不一样,则报错
[python] view plain copy
 
 print?
  1. >>> a  
  2. [6, 5, 4, 3, 2, 1]  
  3. >>> a.sort()  
  4. >>> a  
  5. [1, 2, 3, 4, 5, 6]  

应用中的列表

1.分片 和字符串的分片类似，通过  [start:end]  来获取列表中的一段元素
[python] view plain copy
 
 print?
  1. >>> a  
  2. [1, 2, 3, 4, 5, 6]  
  3. >>> a[0:3]  
  4. [1, 2, 3]  
2.运算  列表也支持"+" "*"的运算，和字符类似表示列表的合并和重复
[python] view plain copy
 
 print?
  1. >>> a = [1,2,3]  
  2. >>> b = [4,5,6]  
  3. >>> a+b  
  4. [1, 2, 3, 4, 5, 6]  
  5. >>> a*2  
  6. [1, 2, 3, 1, 2, 3]  
3.矩阵  矩阵就是相当于一个多维数组，在列表中嵌套列表
[python] view plain copy
 
 print?
  1. >>> a  
  2. [[1, 2, 3], [4, 5, 6], [7, 8, 9]]  
  3. >>> a[1][0]  
  4. 4  
4.更改值, 直接对指定的下标值修改
[python] view plain copy
 
 print?
  1. >>> b  
  2. [4, 5, 6]  
  3. >>> b[1]=100  
  4. >>> b  
  5. [4, 100, 6]  
5.列表的遍历
[python] view plain copy
 
 print?
  1. >>> a=[1,2,3,4,5]  
  2. >>> for i in a:  
  3.     print(i)      
  4. 1  
  5. 2  
  6. 3  
  7. 4  
  8. 5  

 

 

字典(dict)

 

除了列表之外，字典是python中最灵活的数据结构类型。不过不同于列表的是,字典是一个无序的集合，而且字典是通过键值来获取值,而不是通过偏移来获取值。字典的表示形式为 { key：value} 的形式进行保存
class dict(object):
    """
    dict() -> new empty dictionary
    dict(mapping) -> new dictionary initialized from a mapping object's
        (key, value) pairs
    dict(iterable) -> new dictionary initialized as if via:
        d = {}
        for k, v in iterable:
            d[k] = v
    dict(**kwargs) -> new dictionary initialized with the name=value pairs
        in the keyword argument list.  For example:  dict(one=1, two=2)
    """

    def clear(self): # real signature unknown; restored from __doc__
        """ 清除内容 """
        """ D.clear() -> None.  Remove all items from D. """
        pass

    def copy(self): # real signature unknown; restored from __doc__
        """ 浅拷贝 """
        """ D.copy() -> a shallow copy of D """
        pass

    @staticmethod # known case
    def fromkeys(S, v=None): # real signature unknown; restored from __doc__
        """
        dict.fromkeys(S[,v]) -> New dict with keys from S and values equal to v.
        v defaults to None.
        """
        pass

    def get(self, k, d=None): # real signature unknown; restored from __doc__
        """ 根据key获取值，d是默认值 """
        """ D.get(k[,d]) -> D[k] if k in D, else d.  d defaults to None. """
        pass

    def has_key(self, k): # real signature unknown; restored from __doc__
        """ 是否有key """
        """ D.has_key(k) -> True if D has a key k, else False """
        return False

    def items(self): # real signature unknown; restored from __doc__
        """ 所有项的列表形式 """
        """ D.items() -> list of D's (key, value) pairs, as 2-tuples """
        return []

    def iteritems(self): # real signature unknown; restored from __doc__
        """ 项可迭代 """
        """ D.iteritems() -> an iterator over the (key, value) items of D """
        pass

    def iterkeys(self): # real signature unknown; restored from __doc__
        """ key可迭代 """
        """ D.iterkeys() -> an iterator over the keys of D """
        pass

    def itervalues(self): # real signature unknown; restored from __doc__
        """ value可迭代 """
        """ D.itervalues() -> an iterator over the values of D """
        pass

    def keys(self): # real signature unknown; restored from __doc__
        """ 所有的key列表 """
        """ D.keys() -> list of D's keys """
        return []

    def pop(self, k, d=None): # real signature unknown; restored from __doc__
        """ 获取并在字典中移除 """
        """
        D.pop(k[,d]) -> v, remove specified key and return the corresponding value.
        If key is not found, d is returned if given, otherwise KeyError is raised
        """
        pass

    def popitem(self): # real signature unknown; restored from __doc__
        """ 获取并在字典中移除 """
        """
        D.popitem() -> (k, v), remove and return some (key, value) pair as a
        2-tuple; but raise KeyError if D is empty.
        """
        pass

    def setdefault(self, k, d=None): # real signature unknown; restored from __doc__
        """ 如果key不存在，则创建，如果存在，则返回已存在的值且不修改 """
        """ D.setdefault(k[,d]) -> D.get(k,d), also set D[k]=d if k not in D """
        pass

    def update(self, E=None, **F): # known special case of dict.update
        """ 更新
            {'name':'alex', 'age': 18000}
            [('name','sbsbsb'),]
        """
        """
        D.update([E, ]**F) -> None.  Update D from dict/iterable E and F.
        If E present and has a .keys() method, does:     for k in E: D[k] = E[k]
        If E present and lacks .keys() method, does:     for (k, v) in E: D[k] = v
        In either case, this is followed by: for k in F: D[k] = F[k]
        """
        pass

    def values(self): # real signature unknown; restored from __doc__
        """ 所有的值 """
        """ D.values() -> list of D's values """
        return []

    def viewitems(self): # real signature unknown; restored from __doc__
        """ 所有项，只是将内容保存至view对象中 """
        """ D.viewitems() -> a set-like object providing a view on D's items """
        pass

    def viewkeys(self): # real signature unknown; restored from __doc__
        """ D.viewkeys() -> a set-like object providing a view on D's keys """
        pass

    def viewvalues(self): # real signature unknown; restored from __doc__
        """ D.viewvalues() -> an object providing a view on D's values """
        pass

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

    def __contains__(self, k): # real signature unknown; restored from __doc__
        """ D.__contains__(k) -> True if D has a key k, else False """
        return False

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

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

    def __getattribute__(self, name): # real signature unknown; restored from __doc__
        """ x.__getattribute__('name') <==> x.name """
        pass

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

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

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

    def __init__(self, seq=None, **kwargs): # known special case of dict.__init__
        """
        dict() -> new empty dictionary
        dict(mapping) -> new dictionary initialized from a mapping object's
            (key, value) pairs
        dict(iterable) -> new dictionary initialized as if via:
            d = {}
            for k, v in iterable:
                d[k] = v
        dict(**kwargs) -> new dictionary initialized with the name=value pairs
            in the keyword argument list.  For example:  dict(one=1, two=2)
        # (copied from class doc)
        """
        pass

    def __iter__(self): # real signature unknown; restored from __doc__
        """ x.__iter__() <==> iter(x) """
        pass

    def __len__(self): # real signature unknown; restored from __doc__
        """ x.__len__() <==> len(x) """
        pass

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

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

    @staticmethod # known case of __new__
    def __new__(S, *more): # real signature unknown; restored from __doc__
        """ T.__new__(S, ...) -> a new object with type S, a subtype of T """
        pass

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

    def __repr__(self): # real signature unknown; restored from __doc__
        """ x.__repr__() <==> repr(x) """
        pass

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

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

    __hash__ = None
Dict 功能

 

字典的声明

[python] view plain copy
 
 print?
  1. >>> a = {'key1':'value1','key2':'value2'}  
  2. >>> a  
  3. {'key1': 'value1', 'key2': 'value2'}  
  4. >>> b=dict(key1='value1',key2='value2')  
  5. >>> b  
  6. {'key1': 'value1', 'key2': 'value2'}  
也可以通过两个列表的zip方式来实现
[python] view plain copy
 
 print?
  1. >>> a=['key1','key2']  
  2. >>> b=['value1','value2']  
  3. >>> d=dict(zip(a,b))  
  4. >>> d  
  5. {'key1': 'value1', 'key2': 'value2'}  

字典的常用方法

1 get(key,default) 取值
[python] view plain copy
 
 print?
  1. >>> d  
  2. {'key1': 'value1', 'key2': 'value2'}  
  3. >>> d['key1']  直接通过可以获取值,可以不存在则报错  
  4. 'value1'  
  5. >>> d.get('key3','aaa') 通过get可以获取不存在的key,没有返回默认值  
  6. 'aaa'  
2 fromkeys(obj,value)  将obj作为可以，value作为默认值生成一个默认字典，obj可以为字典、元组、列表
[python] view plain copy
 
 print?
  1. >>> aaa = dict.fromkeys((1,2),0) 将元组的值作为key  
  2. >>> aaa  
  3. {1: 0, 2: 0}  
  4. >>> d  
  5. {'key1': 'value1', '1': 'aa', 'key2': 'value2'}  
  6. >>> aaa = dict.fromkeys(d,'123')  将字典d的key作为key  
  7. >>> aaa  
  8. {'key1': '123', '1': '123', 'key2': '123'}  
注意：通过fromkey获取生成的字典,有多个key时,每个key的值是一样的,都是指向内存中的同一个地址,所以当修改其中的一个值时,所有的值都会修改

3 clear()  清空字典
4 items()  将字典的key,value作为元组的方式返回成一个列表
[python] view plain copy
 
 print?
  1. >>> d.items()  
  2. dict_items([('key1', 'value1'), ('1', 'aa'), ('key2', 'value2')])  
  3. >>> for k,v in d.items():  
  4.     print(k,v)  
  5.       
  6. key1 value1  
  7. 1 aa  
  8. key2 value2  
4. keys() 将字典的所有key 作为一个列表返回  
[python] view plain copy
 
 print?
  1. >>> d  
  2. {'key1': 'value1', '1': 'aa', 'key2': 'value2'}  
  3. >>> d.keys()  
  4. dict_keys(['key1', '1', 'key2'])  
5.pop(k,[,d])  删除字典的指定键k，并返回k对应的值,如果k不存在,如果指定默认值d则返回d，否则报错
[python] view plain copy
 
 print?
  1. >>> d  
  2. {'1': 'aa', 'key2': 'value2'}  
  3. >>> d.pop(2,'aaa')  2为key值  
  4. 'aaa'  
6.popitem() 删除字典中的(key:value),并将结果以元组的方式返回.如果字典为空将报错KeyError
[python] view plain copy
 
 print?
  1. >>> d  
  2. {1: '1', 3: '3', 4: '4', 5: '5', 2: '2'}  
  3. >>> d.popitem()  
  4. (3, '3')  
  5. >>> d  
  6. {1: '1', 4: '4', 5: '5', 2: '2'}  
由于字典为无序的集合,popitem是也不会按照顺序进行删除
7.values() 与keys方法类似，将字典的结果以列表方式返回
8.update(dict) 字典更新函数， 相当于合并函数，如dic1.update(dic2),将dic2的所有值复制到dic1中，如果有重复键，则将值更新为dic2中健值。
[python] view plain copy
 
 print?
  1. >>> a1={1:'a',2:'b',3:'c'}  
  2. >>> a2={4:'d',5:'e',2:'f'}  
  3. >>> a1.update(a2)  
  4. >>> a1  
  5. {1: 'a', 2: 'f', 3: 'c', 4: 'd', 5: 'e'}  
9. setdefault(k[,d]) 与get类似，只是这个函数用来给字典赋值，如果指定的k在字典中存在则返回字典中的对应值，如果不存在则给字典增加一个K值，value为d
[python] view plain copy
 
 print?
  1. >>> a1  
  2. {1: 'a', 2: 'f', 3: 'c', 4: 'd', 5: 'e'}  
  3. >>> a1.setdefault(3,'dd')  
  4. 'c'  
  5. >>> a1  
  6. {1: 'a', 2: 'f', 3: 'c', 4: 'd', 5: 'e'}  
  7. >>> a1.setdefault(6,'ddd')  
  8. 'ddd'  
  9. >>> a1  
  10. {1: 'a', 2: 'f', 3: 'c', 4: 'd', 5: 'e', 6: 'ddd'}  
posted @ 2016-06-09 15:44  小新gg  阅读(1064)  评论(0)  编辑  收藏  举报