• Python字符串操作


    自带帮助文档:

    >>> help(str)
    Help on class str in module builtins:
    
    class str(object)
     |  str(object='') -> str
     |  str(bytes_or_buffer[, encoding[, errors]]) -> str
     |  
     |  Create a new string object from the given object. If encoding or
     |  errors is specified, then the object must expose a data buffer
     |  that will be decoded using the given encoding and error handler.
     |  Otherwise, returns the result of object.__str__() (if defined)
     |  or repr(object).
     |  encoding defaults to sys.getdefaultencoding().
     |  errors defaults to 'strict'.
     |  
     |  Methods defined here:
     |  
     |  __add__(self, value, /)
     |      Return self+value.
     |  
     |  __contains__(self, key, /)
     |      Return key in self.
     |  
     |  __eq__(self, value, /)
     |      Return self==value.
     |  
     |  __format__(...)
     |      S.__format__(format_spec) -> str
     |      
     |      Return a formatted version of S as described by format_spec.
     |  
     |  __ge__(self, value, /)
     |      Return self>=value.
     |  
     |  __getattribute__(self, name, /)
     |      Return getattr(self, name).
     |  
     |  __getitem__(self, key, /)
     |      Return self[key].
     |  
     |  __getnewargs__(...)
     |  
     |  __gt__(self, value, /)
     |      Return self>value.
     |  
     |  __hash__(self, /)
     |      Return hash(self).
     |  
     |  __iter__(self, /)
     |      Implement iter(self).
     |  
     |  __le__(self, value, /)
     |      Return self<=value.
     |  
     |  __len__(self, /)
     |      Return len(self).
     |  
     |  __lt__(self, value, /)
     |      Return self<value.
     |  
     |  __mod__(self, value, /)
     |      Return self%value.
     |  
     |  __mul__(self, value, /)
     |      Return self*value.n
     |  
     |  __ne__(self, value, /)
     |      Return self!=value.
     |  
     |  __new__(*args, **kwargs) from builtins.type
     |      Create and return a new object.  See help(type) for accurate signature.
     |  
     |  __repr__(self, /)
     |      Return repr(self).
     |  
     |  __rmod__(self, value, /)
     |      Return value%self.
     |  
     |  __rmul__(self, value, /)
     |      Return self*value.
     |  
     |  __sizeof__(...)
     |      S.__sizeof__() -> size of S in memory, in bytes
     |  
     |  __str__(self, /)
     |      Return str(self).
     |  
     |  capitalize(...)
     |      S.capitalize() -> str
     |      
     |      Return a capitalized version of S, i.e. make the first character
     |      have upper case and the rest lower case.
     |  
     |  casefold(...)
     |      S.casefold() -> str
     |      
     |      Return a version of S suitable for caseless comparisons.
     |  
     |  center(...)
     |      S.center(width[, fillchar]) -> str
     |      
     |      Return S centered in a string of length width. Padding is
     |      done using the specified fill character (default is a space)
     |  
     |  count(...)
     |      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.
     |  
     |  encode(...)
     |      S.encode(encoding='utf-8', errors='strict') -> bytes
     |      
     |      Encode S using the codec registered for encoding. Default encoding
     |      is 'utf-8'. errors may be given to set a different error
     |      handling scheme. Default is 'strict' meaning that encoding errors raise
     |      a UnicodeEncodeError. Other possible values are 'ignore', 'replace' and
     |      'xmlcharrefreplace' as well as any other name registered with
     |      codecs.register_error that can handle UnicodeEncodeErrors.
     |  
     |  endswith(...)
     |      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.
     |  
     |  expandtabs(...)
     |      S.expandtabs(tabsize=8) -> str
     |      
     |      Return a copy of S where all tab characters are expanded using spaces.
     |      If tabsize is not given, a tab size of 8 characters is assumed.
     |  
     |  find(...)
     |      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.
     |  
     |  format(...)
     |      S.format(*args, **kwargs) -> str
     |      
     |      Return a formatted version of S, using substitutions from args and kwargs.
     |      The substitutions are identified by braces ('{' and '}').
     |  
     |  format_map(...)
     |      S.format_map(mapping) -> str
     |      
     |      Return a formatted version of S, using substitutions from mapping.
     |      The substitutions are identified by braces ('{' and '}').
     |  
     |  index(...)
     |      S.index(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.
     |      
     |      Raises ValueError when the substring is not found.
     |  
     |  isalnum(...)
     |      S.isalnum() -> bool
     |      
     |      Return True if all characters in S are alphanumeric
     |      and there is at least one character in S, False otherwise.
     |  
     |  isalpha(...)
     |      S.isalpha() -> bool
     |      
     |      Return True if all characters in S are alphabetic
     |      and there is at least one character in S, False otherwise.
     |  
     |  isdecimal(...)
     |      S.isdecimal() -> bool
     |      
     |      Return True if there are only decimal characters in S,
     |      False otherwise.
     |  
     |  isdigit(...)
     |      S.isdigit() -> bool
     |      
     |      Return True if all characters in S are digits
     |      and there is at least one character in S, False otherwise.
     |  
     |  isidentifier(...)
     |      S.isidentifier() -> bool
     |      
     |      Return True if S is a valid identifier according
     |      to the language definition.
     |      
     |      Use keyword.iskeyword() to test for reserved identifiers
     |      such as "def" and "class".
     |  
     |  islower(...)
     |      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.
     |  
     |  isnumeric(...)
     |      S.isnumeric() -> bool
     |      
     |      Return True if there are only numeric characters in S,
     |      False otherwise.
     |  
     |  isprintable(...)
     |      S.isprintable() -> bool
     |      
     |      Return True if all characters in S are considered
     |      printable in repr() or S is empty, False otherwise.
     |  
     |  isspace(...)
     |      S.isspace() -> bool
     |      
     |      Return True if all characters in S are whitespace
     |      and there is at least one character in S, False otherwise.
     |  
     |  istitle(...)
     |      S.istitle() -> bool
     |      
     |      Return True if S is a titlecased string and there is at least one
     |      character in S, i.e. upper- and titlecase characters may only
     |      follow uncased characters and lowercase characters only cased ones.
     |      Return False otherwise.
     |  
     |  isupper(...)
     |      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.
     |  
     |  join(...)
     |      S.join(iterable) -> str
     |      
     |      Return a string which is the concatenation of the strings in the
     |      iterable.  The separator between elements is S.
     |  
     |  ljust(...)
     |      S.ljust(width[, fillchar]) -> str
     |      
     |      Return S left-justified in a Unicode string of length width. Padding is
     |      done using the specified fill character (default is a space).
     |  
     |  lower(...)
     |      S.lower() -> str
     |      
     |      Return a copy of the string S converted to lowercase.
     |  
     |  lstrip(...)
     |      S.lstrip([chars]) -> str
     |      
     |      Return a copy of the string S with leading whitespace removed.
     |      If chars is given and not None, remove characters in chars instead.
     |  
     |  partition(...)
     |      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.
     |  
     |  replace(...)
     |      S.replace(old, new[, count]) -> str
     |      
     |      Return a copy of S with all occurrences of substring
     |      old replaced by new.  If the optional argument count is
     |      given, only the first count occurrences are replaced.
     |  
     |  rfind(...)
     |      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.
     |  
     |  rindex(...)
     |      S.rindex(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.
     |      
     |      Raises ValueError when the substring is not found.
     |  
     |  rjust(...)
     |      S.rjust(width[, fillchar]) -> str
     |      
     |      Return S right-justified in a string of length width. Padding is
     |      done using the specified fill character (default is a space).
     |  
     |  rpartition(...)
     |      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.
     |  
     |  rsplit(...)
     |      S.rsplit(sep=None, maxsplit=-1) -> list of strings
     |      
     |      Return a list of the words in S, using sep as the
     |      delimiter string, starting at the end of the string and
     |      working to the front.  If maxsplit is given, at most maxsplit
     |      splits are done. If sep is not specified, any whitespace string
     |      is a separator.
     |  
     |  rstrip(...)
     |      S.rstrip([chars]) -> str
     |      
     |      Return a copy of the string S with trailing whitespace removed.
     |      If chars is given and not None, remove characters in chars instead.
     |  
     |  split(...)
     |      S.split(sep=None, maxsplit=-1) -> list of strings
     |      
     |      Return a list of the words in S, using sep as the
     |      delimiter string.  If maxsplit is given, at most maxsplit
     |      splits are done. If sep is not specified or is None, any
     |      whitespace string is a separator and empty strings are
     |      removed from the result.
     |  
     |  splitlines(...)
     |      S.splitlines([keepends]) -> list of strings
     |      
     |      Return a list of the lines in S, breaking at line boundaries.
     |      Line breaks are not included in the resulting list unless keepends
     |      is given and true.
     |  
     |  startswith(...)
     |      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.
     |  
     |  strip(...)
     |      S.strip([chars]) -> str
     |      
     |      Return a copy of the string S with leading and trailing
     |      whitespace removed.
     |      If chars is given and not None, remove characters in chars instead.
     |  
     |  swapcase(...)
     |      S.swapcase() -> str
     |      
     |      Return a copy of S with uppercase characters converted to lowercase
     |      and vice versa.
     |  
     |  title(...)
     |      S.title() -> str
     |      
     |      Return a titlecased version of S, i.e. words start with title case
     |      characters, all remaining cased characters have lower case.
     |  
     |  translate(...)
     |      S.translate(table) -> str
     |      
     |      Return a copy of the string S in which each character has been mapped
     |      through the given translation table. The table must implement
     |      lookup/indexing via __getitem__, for instance a dictionary or list,
     |      mapping Unicode ordinals to Unicode ordinals, strings, or None. If
     |      this operation raises LookupError, the character is left untouched.
     |      Characters mapped to None are deleted.
     |  
     |  upper(...)
     |      S.upper() -> str
     |      
     |      Return a copy of S converted to uppercase.
     |  
     |  zfill(...)
     |      S.zfill(width) -> str
     |      
     |      Pad a numeric string S with zeros on the left, to fill a field
     |      of the specified width. The string S is never truncated.
     |  
     |  ----------------------------------------------------------------------
     |  Static methods defined here:
     |  
     |  maketrans(x, y=None, z=None, /)
     |      Return a translation table usable for str.translate().
     |      
     |      If there is only one argument, it must be a dictionary mapping Unicode
     |      ordinals (integers) or characters to Unicode ordinals, strings or None.
     |      Character keys will be then converted to ordinals.
     |      If there are two arguments, they must be strings of equal length, and
     |      in the resulting dictionary, each character in x will be mapped to the
     |      character at the same position in y. If there is a third argument, it
     |      must be a string, whose characters will be mapped to None in the result.
    
    >>> 
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  • 原文地址:https://www.cnblogs.com/huahuayu/p/8178912.html
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