Help on class str in module __builtin__:

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.

 |

 |  Method resolution order:

 |      str

 |      basestring

 |      object

 |

 |  Methods defined here:

 |

 |  __add__(...)

 |      x.__add__(y) <==> x+y　　#字符串拼接，看+号就知道

 |

 |  __contains__(...)

 |      x.__contains__(y) <==> y in x　　#判断x里字符是否在y里

 |

 |  __eq__(...)

 |      x.__eq__(y) <==> x==y　　

 |

 |  __format__(...)

 |      S.__format__(format_spec) -> string

 |

 |      Return a formatted version of S as described by format_spec.

 |

 |  __ge__(...)

 |      x.__ge__(y) <==> x>=y

 |

 |  __getattribute__(...)

 |      x.__getattribute__('name') <==> x.name　　#获取属性

 |

 |  __getitem__(...)

 |      x.__getitem__(y) <==> x[y]　　#索引取值，详情参考python中的序列

 |

 |  __getnewargs__(...)

 |

 |  __getslice__(...)

 |      x.__getslice__(i, j) <==> x[i:j]　　#切片，也是序列的一种方法

 |

 |      Use of negative indices is not supported.

 |

 |  __gt__(...)

 |      x.__gt__(y) <==> x>y

 |

 |  __hash__(...)

 |      x.__hash__() <==> hash(x)　　

 |

 |  __le__(...)

 |      x.__le__(y) <==> x<=y

 |

 |  __len__(...)

 |      x.__len__() <==> len(x)

 |

 |  __lt__(...)

 |      x.__lt__(y) <==> x<y

 |

 |  __mod__(...)

 |      x.__mod__(y) <==> x%y

 |

 |  __mul__(...)

 |      x.__mul__(n) <==> x*n

 |

 |  __ne__(...)

 |      x.__ne__(y) <==> x!=y

 |

 |  __repr__(...)

 |      x.__repr__() <==> repr(x)

 |

 |  __rmod__(...)

 |      x.__rmod__(y) <==> y%x

 |

 |  __rmul__(...)

 |      x.__rmul__(n) <==> n*x

 |

 |  __sizeof__(...)

 |      S.__sizeof__() -> size of S in memory, in bytes　　#用字节表示在内存中的大小

 |

 |  __str__(...)

 |      x.__str__() <==> str(x)

 |

 |  capitalize(...)

 |      S.capitalize() -> string

 |      '''返回首字母大写字符串副本,对中文无效'''

 |      Return a copy of the string S with only its first character

 |      capitalized.

 |

 |  center(...)

 |      S.center(width[, fillchar]) -> string

 |      '''返回指定宽度（width）的字符串副本，原字符串居中对齐，可指定用什么来填充多余部分（fillchar）默认为空格，关于对齐和填充可以看上篇博文的解释'''

 |      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

 |      '''计数器，返回给定字符串在原字符串出现的次数，也可指定范围'''

 |      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.

 |

 |  decode(...)

 |      S.decode([encoding[,errors]]) -> object

 |      '''解码，将字符串解码成某种字符集'''

 |      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.

 |

 |  encode(...)

 |      S.encode([encoding[,errors]]) -> object

 |      '''编码,将字符串编码'''

 |      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.

 |

 |  endswith(...)

 |      S.endswith(suffix[, start[, end]]) -> bool

 |      '''判断字符串在某范围内(范围用索引指定,不指定默认是整个字符串)是否以指定的字符串(suffix)结尾,返回布尔值'''

 |      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]) -> string

 |      '''将字符串里的制表符(一般用tab建输入,也可以手动使用特殊字符 \t )转换成空格,默认一个制表符转换成8个空格,也可以指定个数(tabsize),并返回一个转换后的副本'''

 |      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

 |      '''在原字符串一定范围内,寻找给定的字符串,找到了返回第一个被找到的字符的索引值,没找到就返回-1'''

 |      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) -> string

 |      '''字符串格式化（比%s更为高级，需要的话自行去了解），(*args, **kwargs)是处理函数传参的一种方式，以后继续讲'''

 |      Return a formatted version of S, using substitutions from args and kwargs.

 |      The substitutions are identified by braces ('{' and '}').

 |

 |  index(...)

 |      S.index(sub [,start [,end]]) -> int

 |      '''和S.find()作用一样，只不过没找到时会报错'''

 |      Like S.find() but raise ValueError when the substring is not found.

 |

 |  isalnum(...)

 |      S.isalnum() -> bool

 |      '''判断字符串内是否由字母和数字组成，返回布尔值'''

 |      Return True if all characters in S are alphanumeric

 |      and there is at least one character in S, False otherwise.

 |

 |  isalpha(...)

 |      S.isalpha() -> bool

 |      '''判断字符串是否全是由字母组成，返回布尔值'''

 |      Return True if all characters in S are alphabetic

 |      and there is at least one character in S, False otherwise.

 |

 |  isdigit(...)

 |      S.isdigit() -> bool

 |      '''判断字符串是否全是由数字组成，返回布尔值'''

 |      Return True if all characters in S are digits

 |      and there is at least one character in S, False otherwise.

 |

 |  islower(...)

 |      S.islower() -> bool

 |      '''判断字符串里的所有字母是否都是小写，当然，前提是字符串里面最少有一个字母，返回布尔值'''

 |      Return True if all cased characters in S are lowercase and there is

 |      at least one cased character in S, False otherwise.

 |

 |  isspace(...)

 |      S.isspace() -> bool

 |      '''判断字符串是否都是由空白字符组成（空格），当然，前提是字符串里面最少有一个空格，返回布尔值'''

 |      Return True if all characters in S are whitespace

 |      and there is at least one character in S, False otherwise.

 |

 |  istitle(...)

 |      S.istitle() -> bool

 |      '''判断字符串是否是标题，而标题的标准就是所有单词的首字母都是大写，其他的都是小写，返回布尔值'''

 |      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.

 |

 |  isupper(...)

 |      S.isupper() -> bool

 |      '''判断字符串里的所有字母是否都是大写，和小写对应'''

 |      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) -> string

 |      '''字符串的拼接，详情看我前面的博文'''

 |      Return a string which is the concatenation of the strings in the

 |      iterable.  The separator between elements is S.

 |

 |  ljust(...)

 |      S.ljust(width[, fillchar]) -> string

 |      '''左对齐，关于对齐和填充可以看我上篇博文'''

 |      Return S left-justified in a string of length width. Padding is

 |      done using the specified fill character (default is a space).

 |

 |  lower(...)

 |      S.lower() -> string

 |      '''返回一个全是小写的字符串副本'''

 |      Return a copy of the string S converted to lowercase.

 |

 |  lstrip(...)

 |      S.lstrip([chars]) -> string or unicode

 |      '''和strip类似，不过只去除左边的空格，可以指定字符'''

 |      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

 |

 |  partition(...)

 |      S.partition(sep) -> (head, sep, tail)

 |      '''和 split 的分隔类似，但返回的是元祖，不过 split 不过保留给定字符，translate 则会保留，并放在中间，没找到则前后为空'''

 |      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]) -> string

 |      '''替换，用新的字符串（new），替换原字符串里有的老字符串（old），用 count 指定替换的次数，不指定则全部替换'''

 |      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.

 |

 |  rfind(...)

 |      S.rfind(sub [,start [,end]]) -> int

 |      '''和S.find()作用类似，不过寻找方向是从右向左'''

 |      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

 |      '''和S.index()作用类似，不过寻找方向是从右向左'''

 |      Like S.rfind() but raise ValueError when the substring is not found.

 |

 |  rjust(...)

 |      S.rjust(width[, fillchar]) -> string

 |      '''右对齐'''

 |      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)

 |      '''partition 的右边操作版本'''

 |      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 [,maxsplit]]) -> list of strings

 |      '''split 的右边操作版，要设置了 maxsplit 才能体现，否则都是全部分隔'''

 |      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.

 |

 |  rstrip(...)

 |      S.rstrip([chars]) -> string or unicode

 |      '''和strip类似，不过只去除右边的空格，可以指定字符'''

 |      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

 |

 |  split(...)

 |      S.split([sep [,maxsplit]]) -> list of strings

 |      '''按照给定的字符进行分割（从左边开始，找到的第一个），返回一个分割由后剩下的字符串组成的列表（不保留sep），

 |　　　　　 maxsplit 指定最大分割次数，否则凡是出现指定的分隔符都会分隔'''

 |      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.

 |

 |  splitlines(...)

 |      S.splitlines(keepends=False) -> list of strings

 |      '''根据换行符分割'''

 |      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

 |      '''判断是否已指定字符串开头，与上面的结尾判断相对应'''

 |      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]) -> string or unicode

 |      '''与 center 的填充相反，这里是移除两边的填充，同样也可以指定移除填充的字符，默认是空格，和 center 类似'''

 |      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

 |

 |  swapcase(...)

 |      S.swapcase() -> string

 |      '''返回一个翻转原字符串字母大小写后的副本'''

 |      Return a copy of the string S with uppercase characters

 |      converted to lowercase and vice versa.

 |

 |  title(...)

 |      S.title() -> string

 |      '''将字符串转换为标题格式'''

 |      Return a titlecased version of S, i.e. words start with uppercase

 |      characters, all remaining cased characters have lowercase.

 |

 |  translate(...)

 |      S.translate(table [,deletechars]) -> string

 |      '''根据参数table给出的表(翻译表，翻译表是通过maketrans方法转换而来)转换字符串的字符, 要过滤掉的字符放到 del 参数中'''

 |      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.

 |

 |  upper(...)

 |      S.upper() -> string

 |      '''将字符串的字母全部大写'''

 |      Return a copy of the string S converted to uppercase.

 |

 |  zfill(...)

 |      S.zfill(width) -> string

 |      '''返回一个给定长度的字符串（小于原字符串无效），原字符右对齐，前面用0填充'''

 |      Pad a numeric string S with zeros on the left, to fill a field

 |      of the specified width.  The string S is never truncated.

 |

 |  ----------------------------------------------------------------------

 |  Data and other attributes defined here:

 |

 |  __new__ = <built-in method __new__ of type object>

 |      T.__new__(S, ...) -> a new object with type S, a subtype of T