Python字符串常见操作

发布时间:2019-03-14 23:32:31编辑:auto阅读(2162)

    Python字符串注意事项

    Python字符串是不可以改变值的,更新一个字符串后要放到另一个变量中去

    Python 不支持char类型的数据类型,也就是不支持单字符类型的数据。

    Python 字符串常用内建函数

    encode(encoding='UTF-8',errors='strict') 以 encoding 指定的编码格式编码字符串,如果出错默认报一个ValueError 的异常,除非 errors 指定的是'ignore'或者'replace'

    find(str, beg=0 end=len(string))

    检测 str 是否包含在字符串中,如果指定范围 beg 和 end ,则检查是否包含在指定范围内,如果包含返回开始的索引值,否则返回-1

    join(seq)

    以指定字符串作为分隔符,将 seq 中所有的元素(的字符串表示)合并为一个新的字符串

    replace(old, new ,max])

    把 将字符串中的 str1 替换成 str2,如果 max 指定,则替换不超过 max 次。

    split(str="", num=string.count(str))

    num=string.count(str)) 以 str 为分隔符截取字符串,如果 num 有指定值,则仅截取 num 个子字符串
    strip([chars]) 在字符串上执行 lstrip()和 rstrip()

    len(string)

    返回字符串长度

    format()

    格式化字符串

    所有内建函数源代码如下:

    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
    stirng
    
    

     

     
      1 class str(basestring):
      2     """
      3     str(object='') -> string
      4     
      5     Return a nice string representation of the object.
      6     If the argument is a string, the return value is the same object.
      7     """
      8     def capitalize(self):  
      9         """ 首字母变大写 """
     10         """
     11         S.capitalize() -> string
     12         
     13         Return a copy of the string S with only its first character
     14         capitalized.
     15         """
     16         return ""
     17 
     18     def center(self, width, fillchar=None):  
     19         """ 内容居中,width:总长度;fillchar:空白处填充内容,默认无 """
     20         """
     21         S.center(width[, fillchar]) -> string
     22         
     23         Return S centered in a string of length width. Padding is
     24         done using the specified fill character (default is a space)
     25         """
     26         return ""
     27 
     28     def count(self, sub, start=None, end=None):  
     29         """ 子序列个数 """
     30         """
     31         S.count(sub[, start[, end]]) -> int
     32         
     33         Return the number of non-overlapping occurrences of substring sub in
     34         string S[start:end].  Optional arguments start and end are interpreted
     35         as in slice notation.
     36         """
     37         return 0
     38 
     39     def decode(self, encoding=None, errors=None):  
     40         """ 解码 """
     41         """
     42         S.decode([encoding[,errors]]) -> object
     43         
     44         Decodes S using the codec registered for encoding. encoding defaults
     45         to the default encoding. errors may be given to set a different error
     46         handling scheme. Default is 'strict' meaning that encoding errors raise
     47         a UnicodeDecodeError. Other possible values are 'ignore' and 'replace'
     48         as well as any other name registered with codecs.register_error that is
     49         able to handle UnicodeDecodeErrors.
     50         """
     51         return object()
     52 
     53     def encode(self, encoding=None, errors=None):  
     54         """ 编码,针对unicode """
     55         """
     56         S.encode([encoding[,errors]]) -> object
     57         
     58         Encodes S using the codec registered for encoding. encoding defaults
     59         to the default encoding. errors may be given to set a different error
     60         handling scheme. Default is 'strict' meaning that encoding errors raise
     61         a UnicodeEncodeError. Other possible values are 'ignore', 'replace' and
     62         'xmlcharrefreplace' as well as any other name registered with
     63         codecs.register_error that is able to handle UnicodeEncodeErrors.
     64         """
     65         return object()
     66 
     67     def endswith(self, suffix, start=None, end=None):  
     68         """ 是否以 xxx 结束 """
     69         """
     70         S.endswith(suffix[, start[, end]]) -> bool
     71         
     72         Return True if S ends with the specified suffix, False otherwise.
     73         With optional start, test S beginning at that position.
     74         With optional end, stop comparing S at that position.
     75         suffix can also be a tuple of strings to try.
     76         """
     77         return False
     78 
     79     def expandtabs(self, tabsize=None):  
     80         """ 将tab转换成空格,默认一个tab转换成8个空格 """
     81         """
     82         S.expandtabs([tabsize]) -> string
     83         
     84         Return a copy of S where all tab characters are expanded using spaces.
     85         If tabsize is not given, a tab size of 8 characters is assumed.
     86         """
     87         return ""
     88 
     89     def find(self, sub, start=None, end=None):  
     90         """ 寻找子序列位置,如果没找到,返回 -1 """
     91         """
     92         S.find(sub [,start [,end]]) -> int
     93         
     94         Return the lowest index in S where substring sub is found,
     95         such that sub is contained within S[start:end].  Optional
     96         arguments start and end are interpreted as in slice notation.
     97         
     98         Return -1 on failure.
     99         """
    100         return 0
    101 
    102     def format(*args, **kwargs): # known special case of str.format
    103         """ 字符串格式化,动态参数,将函数式编程时细说 """
    104         """
    105         S.format(*args, **kwargs) -> string
    106         
    107         Return a formatted version of S, using substitutions from args and kwargs.
    108         The substitutions are identified by braces ('{' and '}').
    109         """
    110         pass
    111 
    112     def index(self, sub, start=None, end=None):  
    113         """ 子序列位置,如果没找到,报错 """
    114         S.index(sub [,start [,end]]) -> int
    115         
    116         Like S.find() but raise ValueError when the substring is not found.
    117         """
    118         return 0
    119 
    120     def isalnum(self):  
    121         """ 是否是字母和数字 """
    122         """
    123         S.isalnum() -> bool
    124         
    125         Return True if all characters in S are alphanumeric
    126         and there is at least one character in S, False otherwise.
    127         """
    128         return False
    129 
    130     def isalpha(self):  
    131         """ 是否是字母 """
    132         """
    133         S.isalpha() -> bool
    134         
    135         Return True if all characters in S are alphabetic
    136         and there is at least one character in S, False otherwise.
    137         """
    138         return False
    139 
    140     def isdigit(self):  
    141         """ 是否是数字 """
    142         """
    143         S.isdigit() -> bool
    144         
    145         Return True if all characters in S are digits
    146         and there is at least one character in S, False otherwise.
    147         """
    148         return False
    149 
    150     def islower(self):  
    151         """ 是否小写 """
    152         """
    153         S.islower() -> bool
    154         
    155         Return True if all cased characters in S are lowercase and there is
    156         at least one cased character in S, False otherwise.
    157         """
    158         return False
    159 
    160     def isspace(self):  
    161         """
    162         S.isspace() -> bool
    163         
    164         Return True if all characters in S are whitespace
    165         and there is at least one character in S, False otherwise.
    166         """
    167         return False
    168 
    169     def istitle(self):  
    170         """
    171         S.istitle() -> bool
    172         
    173         Return True if S is a titlecased string and there is at least one
    174         character in S, i.e. uppercase characters may only follow uncased
    175         characters and lowercase characters only cased ones. Return False
    176         otherwise.
    177         """
    178         return False
    179 
    180     def isupper(self):  
    181         """
    182         S.isupper() -> bool
    183         
    184         Return True if all cased characters in S are uppercase and there is
    185         at least one cased character in S, False otherwise.
    186         """
    187         return False
    188 
    189     def join(self, iterable):  
    190         """ 连接 """
    191         """
    192         S.join(iterable) -> string
    193         
    194         Return a string which is the concatenation of the strings in the
    195         iterable.  The separator between elements is S.
    196         """
    197         return ""
    198 
    199     def ljust(self, width, fillchar=None):  
    200         """ 内容左对齐,右侧填充 """
    201         """
    202         S.ljust(width[, fillchar]) -> string
    203         
    204         Return S left-justified in a string of length width. Padding is
    205         done using the specified fill character (default is a space).
    206         """
    207         return ""
    208 
    209     def lower(self):  
    210         """ 变小写 """
    211         """
    212         S.lower() -> string
    213         
    214         Return a copy of the string S converted to lowercase.
    215         """
    216         return ""
    217 
    218     def lstrip(self, chars=None):  
    219         """ 移除左侧空白 """
    220         """
    221         S.lstrip([chars]) -> string or unicode
    222         
    223         Return a copy of the string S with leading whitespace removed.
    224         If chars is given and not None, remove characters in chars instead.
    225         If chars is unicode, S will be converted to unicode before stripping
    226         """
    227         return ""
    228 
    229     def partition(self, sep):  
    230         """ 分割,前,中,后三部分 """
    231         """
    232         S.partition(sep) -> (head, sep, tail)
    233         
    234         Search for the separator sep in S, and return the part before it,
    235         the separator itself, and the part after it.  If the separator is not
    236         found, return S and two empty strings.
    237         """
    238         pass
    239 
    240     def replace(self, old, new, count=None):  
    241         """ 替换 """
    242         """
    243         S.replace(old, new[, count]) -> string
    244         
    245         Return a copy of string S with all occurrences of substring
    246         old replaced by new.  If the optional argument count is
    247         given, only the first count occurrences are replaced.
    248         """
    249         return ""
    250 
    251     def rfind(self, sub, start=None, end=None):  
    252         """
    253         S.rfind(sub [,start [,end]]) -> int
    254         
    255         Return the highest index in S where substring sub is found,
    256         such that sub is contained within S[start:end].  Optional
    257         arguments start and end are interpreted as in slice notation.
    258         
    259         Return -1 on failure.
    260         """
    261         return 0
    262 
    263     def rindex(self, sub, start=None, end=None):  
    264         """
    265         S.rindex(sub [,start [,end]]) -> int
    266         
    267         Like S.rfind() but raise ValueError when the substring is not found.
    268         """
    269         return 0
    270 
    271     def rjust(self, width, fillchar=None):  
    272         """
    273         S.rjust(width[, fillchar]) -> string
    274         
    275         Return S right-justified in a string of length width. Padding is
    276         done using the specified fill character (default is a space)
    277         """
    278         return ""
    279 
    280     def rpartition(self, sep):  
    281         """
    282         S.rpartition(sep) -> (head, sep, tail)
    283         
    284         Search for the separator sep in S, starting at the end of S, and return
    285         the part before it, the separator itself, and the part after it.  If the
    286         separator is not found, return two empty strings and S.
    287         """
    288         pass
    289 
    290     def rsplit(self, sep=None, maxsplit=None):  
    291         """
    292         S.rsplit([sep [,maxsplit]]) -> list of strings
    293         
    294         Return a list of the words in the string S, using sep as the
    295         delimiter string, starting at the end of the string and working
    296         to the front.  If maxsplit is given, at most maxsplit splits are
    297         done. If sep is not specified or is None, any whitespace string
    298         is a separator.
    299         """
    300         return []
    301 
    302     def rstrip(self, chars=None):  
    303         """
    304         S.rstrip([chars]) -> string or unicode
    305         
    306         Return a copy of the string S with trailing whitespace removed.
    307         If chars is given and not None, remove characters in chars instead.
    308         If chars is unicode, S will be converted to unicode before stripping
    309         """
    310         return ""
    311 
    312     def split(self, sep=None, maxsplit=None):  
    313         """ 分割, maxsplit最多分割几次 """
    314         """
    315         S.split([sep [,maxsplit]]) -> list of strings
    316         
    317         Return a list of the words in the string S, using sep as the
    318         delimiter string.  If maxsplit is given, at most maxsplit
    319         splits are done. If sep is not specified or is None, any
    320         whitespace string is a separator and empty strings are removed
    321         from the result.
    322         """
    323         return []
    324 
    325     def splitlines(self, keepends=False):  
    326         """ 根据换行分割 """
    327         """
    328         S.splitlines(keepends=False) -> list of strings
    329         
    330         Return a list of the lines in S, breaking at line boundaries.
    331         Line breaks are not included in the resulting list unless keepends
    332         is given and true.
    333         """
    334         return []
    335 
    336     def startswith(self, prefix, start=None, end=None):  
    337         """ 是否起始 """
    338         """
    339         S.startswith(prefix[, start[, end]]) -> bool
    340         
    341         Return True if S starts with the specified prefix, False otherwise.
    342         With optional start, test S beginning at that position.
    343         With optional end, stop comparing S at that position.
    344         prefix can also be a tuple of strings to try.
    345         """
    346         return False
    347 
    348     def strip(self, chars=None):  
    349         """ 移除两段空白 """
    350         """
    351         S.strip([chars]) -> string or unicode
    352         
    353         Return a copy of the string S with leading and trailing
    354         whitespace removed.
    355         If chars is given and not None, remove characters in chars instead.
    356         If chars is unicode, S will be converted to unicode before stripping
    357         """
    358         return ""
    359 
    360     def swapcase(self):  
    361         """ 大写变小写,小写变大写 """
    362         """
    363         S.swapcase() -> string
    364         
    365         Return a copy of the string S with uppercase characters
    366         converted to lowercase and vice versa.
    367         """
    368         return ""
    369 
    370     def title(self):  
    371         """
    372         S.title() -> string
    373         
    374         Return a titlecased version of S, i.e. words start with uppercase
    375         characters, all remaining cased characters have lowercase.
    376         """
    377         return ""
    378 
    379     def translate(self, table, deletechars=None):  
    380         """
    381         转换,需要先做一个对应表,最后一个表示删除字符集合
    382         intab = "aeiou"
    383         outtab = "12345"
    384         trantab = maketrans(intab, outtab)
    385         str = "this is string example....wow!!!"
    386         print str.translate(trantab, 'xm')
    387         """
    388 
    389         """
    390         S.translate(table [,deletechars]) -> string
    391         
    392         Return a copy of the string S, where all characters occurring
    393         in the optional argument deletechars are removed, and the
    394         remaining characters have been mapped through the given
    395         translation table, which must be a string of length 256 or None.
    396         If the table argument is None, no translation is applied and
    397         the operation simply removes the characters in deletechars.
    398         """
    399         return ""
    400 
    401     def upper(self):  
    402         """
    403         S.upper() -> string
    404         
    405         Return a copy of the string S converted to uppercase.
    406         """
    407         return ""
    408 
    409     def zfill(self, width):  
    410         """方法返回指定长度的字符串,原字符串右对齐,前面填充0。"""
    411         """
    412         S.zfill(width) -> string
    413         
    414         Pad a numeric string S with zeros on the left, to fill a field
    415         of the specified width.  The string S is never truncated.
    416         """
    417         return ""
    418 
    419     def _formatter_field_name_split(self, *args, **kwargs): # real signature unknown
    420         pass
    421 
    422     def _formatter_parser(self, *args, **kwargs): # real signature unknown
    423         pass
    424 
    425     def __add__(self, y):  
    426         """ x.__add__(y) <==> x+y """
    427         pass
    428 
    429     def __contains__(self, y):  
    430         """ x.__contains__(y) <==> y in x """
    431         pass
    432 
    433     def __eq__(self, y):  
    434         """ x.__eq__(y) <==> x==y """
    435         pass
    436 
    437     def __format__(self, format_spec):  
    438         """
    439         S.__format__(format_spec) -> string
    440         
    441         Return a formatted version of S as described by format_spec.
    442         """
    443         return ""
    444 
    445     def __getattribute__(self, name):  
    446         """ x.__getattribute__('name') <==> x.name """
    447         pass
    448 
    449     def __getitem__(self, y):  
    450         """ x.__getitem__(y) <==> x[y] """
    451         pass
    452 
    453     def __getnewargs__(self, *args, **kwargs): # real signature unknown
    454         pass
    455 
    456     def __getslice__(self, i, j):  
    457         """
    458         x.__getslice__(i, j) <==> x[i:j]
    459                    
    460                    Use of negative indices is not supported.
    461         """
    462         pass
    463 
    464     def __ge__(self, y):  
    465         """ x.__ge__(y) <==> x>=y """
    466         pass
    467 
    468     def __gt__(self, y):  
    469         """ x.__gt__(y) <==> x>y """
    470         pass
    471 
    472     def __hash__(self):  
    473         """ x.__hash__() <==> hash(x) """
    474         pass
    475 
    476     def __init__(self, string=''): # known special case of str.__init__
    477         """
    478         str(object='') -> string
    479         
    480         Return a nice string representation of the object.
    481         If the argument is a string, the return value is the same object.
    482         # (copied from class doc)
    483         """
    484         pass
    485 
    486     def __len__(self):  
    487         """ x.__len__() <==> len(x) """
    488         pass
    489 
    490     def __le__(self, y):  
    491         """ x.__le__(y) <==> x<=y """
    492         pass
    493 
    494     def __lt__(self, y):  
    495         """ x.__lt__(y) <==> x<y """
    496         pass
    497 
    498     def __mod__(self, y):  
    499         """ x.__mod__(y) <==> x%y """
    500         pass
    501 
    502     def __mul__(self, n):  
    503         """ x.__mul__(n) <==> x*n """
    504         pass
    505 
    506     @staticmethod # known case of __new__
    507     def __new__(S, *more):  
    508         """ T.__new__(S, ...) -> a new object with type S, a subtype of T """
    509         pass
    510 
    511     def __ne__(self, y):  
    512         """ x.__ne__(y) <==> x!=y """
    513         pass
    514 
    515     def __repr__(self):  
    516         """ x.__repr__() <==> repr(x) """
    517         pass
    518 
    519     def __rmod__(self, y):  
    520         """ x.__rmod__(y) <==> y%x """
    521         pass
    522 
    523     def __rmul__(self, n):  
    524         """ x.__rmul__(n) <==> n*x """
    525         pass
    526 
    527     def __sizeof__(self):  
    528         """ S.__sizeof__() -> size of S in memory, in bytes """
    529         pass
    530 
    531     def __str__(self):  
    532         """ x.__str__() <==> str(x) """
    533         pass
    534 
    535 str
    536 
    537 s

    Python字符串运算操作

    符号 功能
    + 字符串连接
    * 重复输出字符串
    [] 通过索引获取字符串中字符(注意:第一个字符位置是0)
    [ : ] 截取字符串中的一部分(区间是左闭右开)
    in 成员运算符 - 如果字符串中包含给定的字符返回 True,注意:字符串是可以迭代的,可以用for item in string来迭代出每一个成员。
    not in 成员运算符 - 如果字符串中不包含给定的字符返回 True
    r/R 原始字符串 - 原始字符串:所有的字符串都是直接按照字面的意思来使用,没有转义特殊或不能打印的字符。 原始字符串除在字符串的第一个引号前加上字母 r(可以大小写)以外,与普通字符串有着几乎完全相同的语法。
    % 格式字符串

     

     2018-07-20

    参考链接:http://www.cnblogs.com/wupeiqi/articles/4911365.html

         http://www.runoob.com/python3/python3-string.html     

     

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