python—基础类的那点儿所以然

　　  有道是：‘要知其然，更要知其所以然’~~~那么今天就来说点儿所以然，对python中的int，str，lst，dict和tuple等基础类中的方法做一些解析

那么类是什么呢？

　　官方的解释是这样的：对象是对客观事物的抽象，类是对对象的抽象。

　　因此str是类，int是类，dict、list、tuple等等都是类，但是str却不能直接使用，因为它是抽象的表示了字符串这一类事物，并不能满足表示某个特定字符串的需求，我们必须要str1 = ''初始化一个对象，这时的str1具有str的属性，可以使用str中的方法。

　　类为我们创建对象，提供功能，在python中，一切事物都是对象！（瞧，谁还敢嫌弃我们程序员没有对象，我们可以new一个呀！）

　　在这里介绍些类、对象、方法的查看方式：

　　首先，需要装python，然后至少要有个命令行窗口：

　　查看对象的类型：type(对象名)如图所示：定义了一个平时经常会用到的字符串，但是我不知道它属于哪个类，type一下它就告诉我了。

1 >>> str1 = 'Eva_J' 2 >>> type(str1) 3 <type 'str'>

　　查看类的所有方法：dir(类名)如下，就打印出了所有的类方法。

　　

1 >>> dir(str) 2 ['__add__', '__class__', '__contains__', '__delattr__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__getitem__', '__getnewargs__', '__getslice__', '__gt__', '__hash__', '__init__', '__le__', '__len__', '__lt__', '__mod__', '__mul__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__rmod__', '__rmul__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', '_formatter_field_name_split', '_formatter_parser', 'capitalize', 'center', 'count', 'decode', 'encode', 'endswith', 'expandtabs', 'find', 'format', 'index', 'isalnum', 'isalpha', 'isdigit', 'islower', 'isspace', 'istitle', 'isupper', 'join', 'ljust', 'lower', 'lstrip', 'partition', 'replace', 'rfind', 'rindex', 'rjust', 'rpartition', 'rsplit', 'rstrip', 'split', 'splitlines', 'startswith', 'strip', 'swapcase', 'title', 'translate', 'upper', 'zfill']

　　那么问题来了，方法名为什么有的两边带着下划线，有的没有呢？那是python用来标识私有方法、非私有方法哒，带下划线的标识私有方法，他们通常拥有不止一种调用方    法。如下，我定义了两个字符串，__add__的+的效果是相同的。这里有一个内置方法很特殊：__init__，它是类中的构造方法，会在调用其所在类的时候自动执行。

1 >>> str1 = 'Eva_J' 2 >>> str2 = ' happy every day!' 3 >>> str1.__add__(str2) 4 'Eva_J happy every day!' 5 >>> str1+str2 6 'Eva_J happy every day!'

     在python中，还有一个“help(类名.方法名)”方法：可以查看类的详细功能；“help(类名.功能名)”：查看类中某功能的详细情况

　　

>>> help(str)
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 | | __contains__(...) | x.__contains__(y) <==> y in x | | __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 | | __getitem__(...) | x.__getitem__(y) <==> x[y] | | __getnewargs__(...) | | __getslice__(...) | x.__getslice__(i, j) <==> x[i:j] | | 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 | | __str__(...) | x.__str__() <==> str(x) | | capitalize(...) | S.capitalize() -> string | | Return a copy of the string S with only its first character | capitalized. | | center(...) | 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) | | 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. | | decode(...) | 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. | | encode(...) | 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. | | 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]) -> 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. | | 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) -> string | | 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 | | Like S.find() but raise 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. | | isdigit(...) | S.isdigit() -> bool | | Return True if all characters in S are digits | and there is at least one character in S, False otherwise. | | 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. | | 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. uppercase 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) -> string | | 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 | | 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 | | Return a copy of the string S converted to lowercase. | | lstrip(...) | 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 | | 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]) -> 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. | | 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 | | Like S.rfind() but raise ValueError when the substring is not found. | | rjust(...) | 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) | | 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 [,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. | | rstrip(...) | 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 | | split(...) | 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. | | splitlines(...) | 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. | | 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]) -> 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 | | swapcase(...) | S.swapcase() -> string | | Return a copy of the string S with uppercase characters | converted to lowercase and vice versa. | | title(...) | S.title() -> string | | 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 | | 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 | | Return a copy of the string S converted to uppercase. | | zfill(...) | 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. | | ---------------------------------------------------------------------- | 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

 1 >>> help(str.find)  2 Help on method_descriptor:  3  4 find(...)  5 S.find(sub [,start [,end]]) -> int  6  7 Return the lowest index in S where substring sub is found,  8 such that sub is contained within S[start:end]. Optional  9 arguments start and end are interpreted as in slice notation. 10 11 Return -1 on failure.

　　不要小看了上面的这些方法，它对于看一段新的python代码也大有帮助~

源码解析：

　　下面是python中的一些基础类：

　　Int类：

　　所有方法：

　　　　

1 >>> dir(int) 2 ['__abs__', '__add__', '__and__', '__clas s__', '__cmp__', '__coerce__', '__delattr__', '__div__', '__divmod__', '__doc__', '__float__', '__floordiv__', '__format__', '__getattribute__', '__getnewargs__', '__hash__', '__hex__', '__index__', '__init__', '__int__', '__invert__', '__long__', '__lshift__', '__mod__', '__mul__', '__neg__', '__new__', '__nonzero__', '__oct__', '__or__', '__pos__', '__pow__', '__radd__', '__rand__', '__rdiv__', '__rdivmod__', '__reduce__', '__reduce_ex__', '__repr__', '__rfloordiv__', '__rlshift__', '__rmod__', '__rmul__', '__ror__', '__rpow__', '__rrshift__', '__rshift__', '__rsub__', '__rtruediv__', '__rxor__', '__setattr__', '__sizeof__', '__str__', '__sub__', '__subclasshook__', '__truediv__', '__trunc__', '__xor__', 'bit_length', 'conjugate', 'denominator', 'imag', 'numerator', 'real']

　　源码：

　　

  1 class int(object):  2 """  3  int(x=0) -> int or long  4  int(x, base=10) -> int or long  5  6  Convert a number or string to an integer, or return 0 if no arguments  7  are given. If x is floating point, the conversion truncates towards zero.  8  If x is outside the integer range, the function returns a long instead.  9  10  If x is not a number or if base is given, then x must be a string or  11  Unicode object representing an integer literal in the given base. The  12  literal can be preceded by '+' or '-' and be surrounded by whitespace.  13  The base defaults to 10. Valid bases are 0 and 2-36. Base 0 means to  14  interpret the base from the string as an integer literal.  15  >>> int('0b100', base=0)  16  4  17 """  18 def bit_length(self): # real signature unknown; restored from __doc__  19 """返回表示该数字时所用的最小位数  20  int.bit_length() -> int  21  22  Number of bits necessary to represent self in binary.  23  >>> bin(37)  24  '0b100101'  25  >>> (37).bit_length()  26  6  27 """  28 return 0  29  30 def conjugate(self, *args, **kwargs): # real signature unknown  31 """返回一个复数的共轭复数  32  Returns self, the complex conjugate of any int. """  33 pass  34  35 def __abs__(self): # real signature unknown; restored from __doc__  36 """ 返回绝对值  37  x.__abs__() <==> abs(x) """  38 pass  39  40 def __add__(self, y): # real signature unknown; restored from __doc__  41 """ 返回两个数的和  42  x.__add__(y) <==> x+y """  43 pass  44  45 def __and__(self, y): # real signature unknown; restored from __doc__  46 """ 返回两个数按位与的结果  47  x.__and__(y) <==> x&y """  48 pass  49  50 def __cmp__(self, y): # real signature unknown; restored from __doc__  51 """返回两个数比较的结果，参数从左至右（a，b），a>b返回1，a<b返回-1，a=b返回0  52  x.__cmp__(y) <==> cmp(x,y) """  53 pass  54  55 def __coerce__(self, y): # real signature unknown; restored from __doc__  56 """a.__coerce__(b),强制返回一个元组（a，b）  57  x.__coerce__(y) <==> coerce(x, y) """  58 pass  59  60 def __divmod__(self, y): # real signature unknown; restored from __doc__  61 """ 相除，得到商和余数组成的元组  62  x.__divmod__(y) <==> divmod(x, y) """  63 pass  64  65 def __div__(self, y): # real signature unknown; restored from __doc__  66 """返回两数相除的商  67  x.__div__(y) <==> x/y """  68 pass  69  70 def __float__(self): # real signature unknown; restored from __doc__  71 """将数据类型强制转换为float  72  x.__float__() <==> float(x) """  73 pass  74  75 def __floordiv__(self, y): # real signature unknown; restored from __doc__  76 """ 不保留小数点后的小数除法,也可以用‘//’来表示：a//b，我们亲切地称之为“地板除”！！！  77  x.__floordiv__(y) <==> x//y """  78 pass  79  80 def __format__(self, *args, **kwargs): # real signature unknown  81 """ 格式化"""  82 pass  83  84 def __getattribute__(self, name): # real signature unknown; restored from __doc__  85 """无条件被调用，通过实例访问属性  86  x.__getattribute__('name') <==> x.name """  87 pass  88  89 def __getnewargs__(self, *args, **kwargs): # real signature unknown  90 """ 内部调用 __new__方法或创建对象时传入参数使用 """  91 pass  92  93 def __hash__(self): # real signature unknown; restored from __doc__  94 """ 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  95  x.__hash__() <==> hash(x) """  96 pass  97  98 def __hex__(self): # real signature unknown; restored from __doc__  99 """ 返回当前数的 十六进制 表示 100  x.__hex__() <==> hex(x) """ 101 pass 102 103 def __index__(self): # real signature unknown; restored from __doc__ 104 """ 用于切片，对数字无意义 105  x[y:z] <==> x[y.__index__():z.__index__()] """ 106 pass 107 108 def __init__(self, x, base=10): # known special case of int.__init__ 109 """构造函数 110  int(x=0) -> int or long 111  int(x, base=10) -> int or long 112 113  Convert a number or string to an integer, or return 0 if no arguments 114  are given. If x is floating point, the conversion truncates towards zero. 115  If x is outside the integer range, the function returns a long instead. 116 117  If x is not a number or if base is given, then x must be a string or 118  Unicode object representing an integer literal in the given base. The 119  literal can be preceded by '+' or '-' and be surrounded by whitespace. 120  The base defaults to 10. Valid bases are 0 and 2-36. Base 0 means to 121  interpret the base from the string as an integer literal. 122  >>> int('0b100', base=0) 123  4 124  # (copied from class doc) 125 """ 126 pass 127 128 def __int__(self): # real signature unknown; restored from __doc__ 129 """ 转换为整数 130  x.__int__() <==> int(x) """ 131 pass 132 133 def __invert__(self): # real signature unknown; restored from __doc__ 134 """按位求反 135  x.__invert__() <==> ~x """ 136 pass 137 138 def __long__(self): # real signature unknown; restored from __doc__ 139 """转换为长整数 140  x.__long__() <==> long(x) """ 141 pass 142 143 def __lshift__(self, y): # real signature unknown; restored from __doc__ 144 """ 左移，相对二进制的操作 145  x.__lshift__(y) <==> x<<y """ 146 pass 147 148 def __mod__(self, y): # real signature unknown; restored from __doc__ 149 """ 取余 150  x.__mod__(y) <==> x%y """ 151 pass 152 153 def __mul__(self, y): # real signature unknown; restored from __doc__ 154 """ 返回两数相乘的积 155  x.__mul__(y) <==> x*y """ 156 pass 157 158 def __neg__(self): # real signature unknown; restored from __doc__ 159 """ 返回一个数的负数，个人觉得和相反数没差 160  x.__neg__() <==> -x """ 161 pass 162 163 @staticmethod # known case of __new__ 164 def __new__(S, *more): # real signature unknown; restored from __doc__ 165 """ 创建一个int类的新对象 166  T.__new__(S, ...) -> a new object with type S, a subtype of T """ 167 pass 168 169 def __nonzero__(self): # real signature unknown; restored from __doc__ 170 """ 判断一个数是不是0 171  x.__nonzero__() <==> x != 0 """ 172 pass 173 174 def __oct__(self): # real signature unknown; restored from __doc__ 175 """ 返回该值的 八进制 表示 176  x.__oct__() <==> oct(x) """ 177 pass 178 179 def __or__(self, y): # real signature unknown; restored from __doc__ 180 """ 位运算，或，针对二进制数 181  x.__or__(y) <==> x|y """ 182 pass 183 184 def __pos__(self): # real signature unknown; restored from __doc__ 185 """ 并没什么卵用，说是a.__pos__()，会返回一个+a，但是不管输入整数还是负数，返回值都是他本身，感觉歪果仁真有幽默感 186  x.__pos__() <==> +x """ 187 pass 188 189 def __pow__(self, y, z=None): # real signature unknown; restored from __doc__ 190 """ 幂，次方 191  x.__pow__(y[, z]) <==> pow(x, y[, z]) """ 192 pass 193 194 def __radd__(self, y): # real signature unknown; restored from __doc__ 195 """x.__radd__(y) <==> y+x """ 196 pass 197 198 def __rand__(self, y): # real signature unknown; restored from __doc__ 199 """x.__rand__(y) <==> y&x """ 200 pass 201 202 def __rdivmod__(self, y): # real signature unknown; restored from __doc__ 203 """ x.__rdivmod__(y) <==> divmod(y, x) """ 204 pass 205 206 def __rdiv__(self, y): # real signature unknown; restored from __doc__ 207 """ x.__rdiv__(y) <==> y/x """ 208 pass 209 210 def __repr__(self): # real signature unknown; restored from __doc__ 211 """ 转化为解释器可读取的形式 212  x.__repr__() <==> repr(x) """ 213 pass 214 215 def __rfloordiv__(self, y): # real signature unknown; restored from __doc__ 216 """ 217  x.__rfloordiv__(y) <==> y//x """ 218 pass 219 220 def __rlshift__(self, y): # real signature unknown; restored from __doc__ 221 """ x.__rlshift__(y) <==> y<<x """ 222 pass 223 224 def __rmod__(self, y): # real signature unknown; restored from __doc__ 225 """ x.__rmod__(y) <==> y%x """ 226 pass 227 228 def __rmul__(self, y): # real signature unknown; restored from __doc__ 229 """ x.__rmul__(y) <==> y*x """ 230 pass 231 232 def __ror__(self, y): # real signature unknown; restored from __doc__ 233 """ x.__ror__(y) <==> y|x """ 234 pass 235 236 def __rpow__(self, x, z=None): # real signature unknown; restored from __doc__ 237 """ y.__rpow__(x[, z]) <==> pow(x, y[, z]) """ 238 pass 239 240 def __rrshift__(self, y): # real signature unknown; restored from __doc__ 241 """ x.__rrshift__(y) <==> y>>x """ 242 pass 243 244 def __rshift__(self, y): # real signature unknown; restored from __doc__ 245 """ x.__rshift__(y) <==> x>>y """ 246 pass 247 248 def __rsub__(self, y): # real signature unknown; restored from __doc__ 249 """ x.__rsub__(y) <==> y-x """ 250 pass 251 252 def __rtruediv__(self, y): # real signature unknown; restored from __doc__ 253 """ x.__rtruediv__(y) <==> y/x """ 254 pass 255 256 def __rxor__(self, y): # real signature unknown; restored from __doc__ 257 """ x.__rxor__(y) <==> y^x """ 258 pass 259 260 def __str__(self): # real signature unknown; restored from __doc__ 261 """ 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 262  x.__str__() <==> str(x) """ 263 pass 264 265 def __sub__(self, y): # real signature unknown; restored from __doc__ 266 """ 返回两数相减的差 267  x.__sub__(y) <==> x-y """ 268 pass 269 270 def __truediv__(self, y): # real signature unknown; restored from __doc__ 271 """返回两数相除的商，这里的除是精确的除法，不会省略小数点后的值 272  x.__truediv__(y) <==> x/y """ 273 pass 274 275 def __trunc__(self, *args, **kwargs): # real signature unknown 276 """返回数值被截取为整形的值，在整形中无意义 277  Truncating an Integral returns itself. """ 278 pass 279 280 def __xor__(self, y): # real signature unknown; restored from __doc__ 281 """ 按位异或 282  x.__xor__(y) <==> x^y """ 283 pass 284 285 denominator = property(lambda self: object(), lambda self, v: None, lambda self: None) # default 286 """ 分母 = 1 """ 287 """the denominator of a rational number in lowest terms""" 288 289 imag = property(lambda self: object(), lambda self, v: None, lambda self: None) # default 290 """ 虚数，无意义 """ 291 """the imaginary part of a complex number""" 292 293 numerator = property(lambda self: object(), lambda self, v: None, lambda self: None) # default 294 """ 分子 = 数字大小 """ 295 """the numerator of a rational number in lowest terms""" 296 297 real = property(lambda self: object(), lambda self, v: None, lambda self: None) # default 298 """ 实数，无意义 """ 299 """the real part of a complex number""" 

　　我已经在源码中加入了注释，原谅我后面很多函数没有加注释都，因为那些前面在前面已近出现过了，只是在前面多了一个'r'的，比如and，变成了rand，在这里统一总结，就是参数的顺序从右到左反过来了。比如原本的a.__div__(b)是a/b，但是a.__rdiv__(b)的表示的就是b/a，对！就是这么坑爹！

　　在int类中，比较普通的就是+，-，*，/，%，位运算，进制间以及数据类型间的转换。下面对于比较特别但是常用的方法再进行一下记录：

　　（1） __cmp__:比较两个数的大小

　　　

1 >>> a = 12
2 >>> b = 15 3 >>> cmp(a,b) #比较两个参数的值，如果第一个参数小于第二个参数，返回-1 4 -1 5 >>> cmp(b,a) #比较两个参数的值，如果第一个参数大于第二个参数，返回1 6 1 7 >>> c = 12 8 >>> a.__cmp__(c) #比较两个参数的值，如果第一个参数大于第二个参数，返回0 9 0 #cmp方法也有两种调用方式

　　　　（2）__neg__/__abs__:取相反数/取绝对值

 1 >>> a = -12
 2 >>> b = 21  3 >>> a.__neg__() #求相反数  4 12  5 >>> b.__neg__()  6 -21  7 >>> a.__abs__() #求绝对值  8 12  9 >>> b.__abs__() 10 21

  　　　 （3）__coerce__:强制返回一个元组（好吧，我承认这个并不常用，就是和divmod比较看看）

　　　　（4）__divmod__:返回两个数相除的商和余数组成的元组（商，余数）       　　　　　　　　  应用:显示数据分页

1 >>> a = 102
2 >>> b = 10 3 >>> a.__divmod__(b) 4 (10, 2) 5 >>> a.__coerce__(b) 6 (102, 10)

　   　　　 （5）__floordiv__:不保留小数点后的小数除法，在这儿把所有的除法都整理了，然而我并没发现__div__和__floordiv__的区别啊~~~

　　　　　　

 1 >>> a = 13
 2 >>> b = 2  3 >>> a.__div__(b)  4 6  5 >>> a.__truediv__(b)  6 6.5  7 >>> a.__floordiv__(b)  8 6  9 >>> a/b 10 6 11 >>> a//b 12 6

  　　    （6）__repr__/__str__:转化为解释器可读取的形式/转换为人阅读的形式     

　　

　　Long类：

　　

>>> dir(long)
['__abs__', '__add__', '__and__', '__class__', '__cmp__', '__coerce__', '__delattr__', '__div__', '__divmod__', '__doc__', '__float__', '__floordiv__', '__format__', '__getattribute__', '__getnewargs__', '__hash__', '__hex__', '__index__', '__init__', '__int__', '__invert__', '__long__', '__lshift__', '__mod__', '__mul__', '__neg__', '__new__', '__nonzero__', '__oct__', '__or__', '__pos__', '__pow__', '__radd__', '__rand__', '__rdiv__', '__rdivmod__', '__reduce__', '__reduce_ex__', '__repr__', '__rfloordiv__', '__rlshift__', '__rmod__', '__rmul__', '__ror__', '__rpow__', '__rrshift__', '__rshift__', '__rsub__', '__rtruediv__', '__rxor__', '__setattr__', '__sizeof__', '__str__', '__sub__', '__subclasshook__', '__truediv__', '__trunc__', '__xor__', 'bit_length', 'conjugate', 'denominator', 'imag', 'numerator', 'real']

      长整形就是长长的整形。。。现在的操作系统大部分int类型的表示范围是2^32,而长整形就是2^64，在python里，不需要程序员手动的转换int和long的数据类型，当数值的大小超过了int的表示范围，python会自动将数据类型转换为long型，就是这么智能！！！既然long和int同表示整形，那么他们包含的方法也是差不多的，在这里就不再介绍了。

　　float类：

　　float类定义了类似3.14,6.28这样的小数。

>>> dir(float)
['__abs__', '__add__', '__class__', '__coerce__', '__delattr__', '__div__', '__divmod__', '__doc__', '__eq__', '__float__', '__floordiv__', '__format__', '__ge__', '__getattribute__', '__getformat__', '__getnewargs__', '__gt__', '__hash__', '__init__', '__int__', '__le__', '__long__', '__lt__', '__mod__', '__mul__', '__ne__', '__neg__', '__new__', '__nonzero__', '__pos__', '__pow__', '__radd__', '__rdiv__', '__rdivmod__', '__reduce__', '__reduce_ex__', '__repr__', '__rfloordiv__', '__rmod__', '__rmul__', '__rpow__', '__rsub__', '__rtruediv__', '__setattr__', '__setformat__', '__sizeof__', '__str__', '__sub__', '__subclasshook__', '__truediv__', '__trunc__', 'as_integer_ratio', 'conjugate', 'fromhex', 'hex', 'imag', 'is_integer', 'real']

　　

　　我们在创建对象的时候，python也会很聪明的识别出float类型，在计算的时候也是这样，不管表达式中有多少整形多少浮点型，只要存在浮点型，那么所有计算都按照浮点型计算，得出的结果也会是float类型。其余方法和整形并没有太大差别，在这里也不做详细总结了。

>>> a  = 3.14
>>> type(a)
<type 'float'>
>>> b = 6.28
>>> c = b/a
>>> print c,type(c)
2.0 <type 'float'>
>>> d = 8
>>> type(d)
<type 'int'>
>>> d/c
4.0
>>> type(d/c)
<type 'float'>

　　

　　Str类：

>>> dir(str)
['__add__', '__class__', '__contains__', '__delattr__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__getitem__', '__getnewargs__', '__getslice__', '__gt__', '__hash__', '__init__', '__le__', '__len__', '__lt__', '__mod__', '__mul__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__rmod__', '__rmul__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', '_formatter_field_name_split', '_formatter_parser', 'capitalize', 'center', 'count', 'decode', 'encode', 'endswith', 'expandtabs', 'find', 'format', 'index', 'isalnum', 'isalpha', 'isdigit', 'islower', 'isspace', 'istitle', 'isupper', 'join', 'ljust', 'lower', 'lstrip', 'partition', 'replace', 'rfind', 'rindex', 'rjust', 'rpartition', 'rsplit', 'rstrip', 'split', 'splitlines', 'startswith', 'strip', 'swapcase', 'title', 'translate', 'upper', 'zfill']

　　

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，则异常 """
        """
        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，则返回-1  """
        S.index(sub [,start [,end]]) -> int
        
        Like S.find() but raise ValueError when the substring is not found.
        """
        return 0

    def isalnum(self):  
        """ 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):  
        """是否空格
        S.isspace() -> bool
        
        Return True if all characters in S are whitespace
        and there is at least one character in S, False otherwise.
        """
        return False

    def istitle(self):  
        """是否标题
        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):  
        """是否大写
        S.isupper() -> bool
        
        Return True if all cased characters in S are uppercase and there is
        at least one cased character in S, False otherwise.
        """
        return False

    def join(self, iterable):  
        """ 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

　　接下来对于str类中一些常用的方法进行说明：

 　 （1）capitalize：将首字母大写

>>> name = 'eva'
>>> name.capitalize()
'Eva'

　　（2）center/ljust/rjst：固定字符串长度，居中/居左/居右 ，下面是使用示例，当然没有正常人会上来就这么用，一般用在打印列表和字典的时候整理格式。

>>> str1.ljust(20,)         #设置格式左对齐，其余部分默认情况下，以空格填充
'hello,Eva!          '
>>> str1.center(20,'*')　　　#设置格式左对齐，剩余部分已“*”填充
'*****hello,Eva!*****'
>>> str1.rjust(20,'&')　　　　#设置格式左对齐，剩余部分已“&”填充
'&&&&&&&&&&hello,Eva!'

　　

　　 （3）count：子序列个数，用来统计一个字符串中包含指定子序列的个数。这个子序列可以是一个字符，也可以是多个字符~~

>>> str1 = 'hello,Eva.Have a nice day'
>>> str1.count('a')
4
>>> str1.count('va')
1

　　 （4）encode/decode：编码/解码，如下左图，各个编码之间是不能直接转换的，计算机内存中默认存储的编码格式是unicode，所以当我们需要将编码在utf8和gbk之间转换的时候，都需要和unicode做操作。
   　　　　我的终端编码是gbk编码的，当我创建一个string = '景'时，string就被存储成gbk格式。此时我想把gbk格式转换成utf8格式，就要先将原gbk格式的string转换成unicode格式，然后再将unicode转换成utf8格式。如下右图，老师说，把这个字整乱码了我们的目的就达到了，哈~

             

　　 （5）endswith:是否以...（子串）结尾。这里的子串依然可以是一个或多个字符。

>>> str1 = 'hello,Eva.Have a nice day'
>>> str1.endswith('day')
True

　　 （6）expandtabs：将tab转换成空格，默认一个tab转换成8个空格。当然这里也可以自行指定转换成多少个空格，要不是怕写不下，我就指定它转成千八百个。。。

>>> name = '    Eva'
>>> name.expandtabs()
'        Eva'
>>> name.expandtabs(20)
'                    Eva'

　　 （7）find：返回字符串中第一个子序列的下标。

　　　　  rfind：和find用法一样，只是它是从右向左查找

　　        index：和find的左右一致，只是find找不到的时候会返回-1，而index找不到的时候会报错

　　　　  值得注意的是，当我们在一个字符串中查找某一个子序列的时候，如果这个字符串中含有多个子序列，只会返回第一个找到的下标，不会返回其他的。

>>> name  = 'hello,eva,how are you'
>>> name.find('o')
4
>>> name.find('t')
-1
>>> name.index('e')
1
>>> name.index('t')

Traceback (most recent call last):
  File "<pyshell#234>", line 1, in <module>
    name.index('t')
ValueError: substring not found

　　 （8）format：各种格式化，动态参数。

>>> str1 = 'I\'m {0},age {1}'
>>> str2 = 'I\'m {name},age {age}'
>>> lst = ['Eva','18']
>>> dic = {'name':'Eva','age':'18'}
>>> str1.format('Eva','18')
"I'm Eva,age 18"
>>> str1.format(*lst)
"I'm Eva,age 18"
>>> str2.format(age = '18',name = 'Eva')
"I'm Eva,age 18"
>>> str2.format(**dic)
"I'm Eva,age 18"

　　 （9）isalnum/isalpha/isdigit/isspace/islower/istitle/isupper:是否是字母或数字/是否字母/是否数字/是否空格/是否小写/是否标题/是否全大写，总之都是一些判断的方法，返回的不是True就是False。。。

　　 （10）partition/split：这两个方法都用来分割。

　　partition会将指定的子串串提取并将子串两侧内容分割，只匹配一次，并返回元祖；

　　split会根据指定子串，将整个字符串所有匹配的子串匹配到并剔除，将其他内容分割，返回数组。

>>> food = 'apple,banana,chocolate'
>>> food.split(',')
['apple', 'banana', 'chocolate']
>>> food.partition(',')
('apple', ',', 'banana,chocolate')

　　 （11）replace：替换。会替换字符串中所有符合条件的子串。。。原谅我的chinglish。。。

>>> str1 = 'I\'m Rita,Do you remember,Rita?'
>>> str1.replace('Rita','Eva')
"I'm Eva,Do you remember,Eva?"

　　 （12）swapcase：大写变小写，小写变大写

>>> str1 = 'I\'m Eva'
>>> str1.swapcase()
"i'M eVA"

　　 （13）translate：替换，删除字符串。这个方法的使用比较麻烦，在使用前需要引入string类，并调用其中的maketrans方法建立映射关系。这样，在translate方法中，加入映射参数，就可以看到效果了。如下‘aeiou’分别和‘12345’建立了映射关系，于是在最后，aeiou都被12345相应的替换掉了，translate第二个参数是删除，它删除了所有的‘.’

>>> in_tab = 'aeiou'
>>> out_tab = '12345'
>>> import string
>>> transtab = string.maketrans(in_tab,out_tab)
>>> str = 'this is a translate example...wow!'
>>> str1 = 'this is a translate example...wow!'
>>> print str1.translate(transtab,'..')
th3s 3s 1 tr1nsl1t2 2x1mpl2w4w!

　　

　　List类：

>>> dir(list)
['__add__', '__class__', '__contains__', '__delattr__', '__delitem__', '__delslice__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__getitem__', '__getslice__', '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__iter__', '__le__', '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__reversed__', '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__sizeof__', '__str__', '__subclasshook__', 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove', 'reverse', 'sort']

 

class list(object):
    """
    list() -> new empty list
    list(iterable) -> new list initialized from iterable's items
    """在数组的末尾新增一项
    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__
        """ 查看lst中某一项出现的次数
        L.count(value) -> integer -- return number of occurrences of value """
        return 0

    def extend(self, iterable): # real signature unknown; restored from __doc__
        """将原列表与其他列表扩展成新列表
        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__
        """返回列表中第一个匹配项的下标，找不到会报错
        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__
        """在指定位置插入项
        L.insert(index, object) -- insert object before index """
        pass

    def pop(self, index=None): # real signature unknown; restored from __doc__
        """返回指定位置的值，并将其从列表中删除。默认对末尾项操作
        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__
        """从列表中移除第一个符合与指定值相等的项
        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__
        """列表反转
        L.reverse() -- reverse *IN PLACE* """
        pass

    def sort(self, cmp=None, key=None, reverse=False): # real signature unknown; restored from __doc__
        """排序，数字、字符串按照ASCII，中文按照unicode从小到大排序。
        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__
        """ 字符串拼接
        x.__add__(y) <==> x+y """
        pass

    def __contains__(self, y): # real signature unknown; restored from __doc__
        """ 判断列表中是否包含某一项
        x.__contains__(y) <==> y in x """
        pass

    def __delitem__(self, y): # real signature unknown; restored from __doc__
        """删除列表中指定下标的项
        x.__delitem__(y) <==> del x[y] """
        pass

    def __delslice__(self, i, j): # real signature unknown; restored from __doc__
        """删除指定下标之间的内容，向下包含
        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__
        """ 判断两个列表是否相等
        x.__eq__(y) <==> x==y """
        pass

    def __getattribute__(self, name): # real signature unknown; restored from __doc__
        """ 无条件被调用，通过实例访问属性。
        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

list         

　　接下来还是继续看一些list类中的常用方法：

　　
 　　（1）append：向列表中添加项

　　　　   insert：在列表的指定位置加入值

　　　　　extend：列表的扩展；那么列表可以自己扩展自己么？？？当然是可以的啦！

>>> 
>>> a = [1,2,3,4]
>>> a.append(5)
>>> a
[1, 2, 3, 4, 5]
>>> b = [6,7]
>>> a.extend(b)
>>> a
[1, 2, 3, 4, 5, 6, 7]
>>> a.insert(2,0)
>>> a
[1, 2, 0, 3, 4, 5, 6, 7]

　　　　（2）index：返回列表中第一个匹配项的下标

　　　　       __contain__:查看列表中是否包含某一项

　　　　　　 count：查看列表中某一项出现的次数

>>> a
[1, 2, 0, 3, 4, 5, 6, 7]
>>> a.index(0)
2
>>> a.__contains__(7)
True
>>> a.__contains__(8)
False
>>> a.count(5)
1

　　　　（3）pop:删除并返回指定下标的值，默认为列表的最后一个值

　　　　　　 remove：删除列表中与指定值匹配的第一个值

                  __delitem__:删除指定下标的值

　　　　　　__delslice__:删除指定下标区域内的所有值，下标向下包含

>>> a
[1, 2, 0, 3, 4, 5, 6, 7]
>>> a.pop()
7
>>> a
[1, 2, 0, 3, 4, 5, 6]
>>> a.pop(2)
0
>>> a
[1, 2, 3, 4, 5, 6]
>>> a.remove(2)
>>> a
[1, 3, 4, 5, 6]
>>> a.__delitem__(0)
>>> a
[3, 4, 5, 6]
>>> a.__delslice__(0,2)
>>> a
[5, 6]

　　　　 （4）reverse：列表反转，这个反转并没有什么编码顺序，就是单纯的把原来的列表从头到尾调转过来而已。。。
 　　　　　　  sort：排序，数字、字符串按照ASCII，中文按照unicode从小到大排序。

>>> a = [5,4,6,8,2,6,9]
>>> a.sort()
>>> a
[2, 4, 5, 6, 6, 8, 9]
>>> a.reverse()
>>> a
[9, 8, 6, 6, 5, 4, 2]

　　Tuple类：

>>> dir(tuple)
['__add__', '__class__', '__contains__', '__delattr__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__getitem__', '__getnewargs__', '__getslice__', '__gt__', '__hash__', '__init__', '__iter__', '__le__', '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__rmul__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', 'count', 'index']

　　　　tuple和list基本相同，但是tuple是不可修改的。所以也就没有添加，删除，修改等方法。但是count，__contain__等方法还是存在的，和list中用法相同，这里就不重复介绍了。

　　Dict类：

>>> dir(dict)
['__class__', '__cmp__', '__contains__', '__delattr__', '__delitem__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__getitem__', '__gt__', '__hash__', '__init__', '__iter__', '__le__', '__len__', '__lt__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__setitem__', '__sizeof__', '__str__', '__subclasshook__', 'clear', 'copy', 'fromkeys', 'get', 'has_key', 'items', 'iteritems', 'iterkeys', 'itervalues', 'keys', 'pop', 'popitem', 'setdefault', 'update', 'values', 'viewitems', 'viewkeys', 'viewvalues']

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

　　　　字典是python数据类型中的一大亮点，在其中占有着独特的地位，在这里先介绍一下字典的特性，和list不同，字典是无序的，它依靠key和value之间的联系进行索引，由于这种特殊的索引方式，字典中不可以有重复的key。

　　　　接下来还是就详细解析一些dict类中的常用方法：

 　　　　（1）keys/values/items：取所有字典的key/取所有字典的value/取所有字典的key，value

　　　　

>>> dic = {'name':'Eva','age':18}
>>> dic.keys()
['age', 'name']
>>> dic.values()
[18, 'Eva']
>>> dic.items()
[('age', 18), ('name', 'Eva')]

　　　　（2）已知key的情况下，获取value的值时可以使用‘字典名[key值]’的方法，在循环遍历中，尽管字典提供了for k，v in dic.items()的方法，但是为了避免占用内存空间，我们还是遍历key，再利用key的值就可以获取到value啦！

　　　　get：字典名[key值]的方式有一点弊端，那就是当key值不存在的时候会报错，这个时候我们使用get方法，可以避免报错的情况

>>> dic = {'name':'Eva','age':18}
>>> for n in dic:
    print 'key:',n,'value:',dic[n]

    
key: age value: 18
key: name value: Eva
>>> dic['name']
'Eva'
>>> dic['Gender']

Traceback (most recent call last):
  File "<pyshell#384>", line 1, in <module>
    dic['Gender']
KeyError: 'Gender'
>>> dic.get('name')
'Eva'
>>> dic.get('Gender')
>>> 

 　　　　（3）clear：清空字典

>>> dic = {'name':'Eva','age':18}
>>> dic.clear()
>>> dic
{}

　　　　（4）pop：根据指定的key删除一组数据

　　　　　　  popitem：随机的删除一组数据。。。我觉得这就是python在逗我。。。

>>> dic
{'Gender': 'female', 'age': 18, 'name': 'Eva'}
>>> dic.popitem()
('Gender', 'female')
>>> dic.pop('age')
18
>>> dic
{'name': 'Eva'}

　　　　（5）setdefault：dic.setdefault[key1],key1存在，则返回value1，不存在，则自动创建value = 'None'

>>> dic
{'name': 'Eva'}
>>> dic.setdefault('name')
'Eva'
>>> dic.setdefault('age')
>>> dic
{'age': None, 'name': 'Eva'}

　　　　（6）update:dict1.update(dict2),判断dict2中的每一个key在dict1中是否存在，存在：就将dict1中的value更新成dict2中的，不存在：将key和value都复制过去

>>> dic
{'age': None, 'name': 'Eva'}
>>> dic1 = dic
>>> 
>>> dic1
{'age': None, 'name': 'Eva'}
>>> dic2 = {'age': 18, 'name': 'Eva','gender':'female'}
>>> dic1.update(dic2)
>>> dic1
{'name': 'Eva', 'gender': 'female', 'age': 18}

　　　　（7）fromkeys：可以通过list创建一个字典，

　　　　dict.fromkeys([1,2,3],'test'),可以创建一个字典，但是如果a.fromkeys([1,2,3]，[]},创建的字典的值都是一个空列表，那么其中一个列表的值发生了变化，所有的列表都会跟着发生变化，因为这个方法就是很傻很天真的把所有value的指针指向了同一个列表。所以感觉这个方法也是逗我玩儿的。。。

>>> a = dict.fromkeys([1,2,3],'test')
>>> a
{1: 'test', 2: 'test', 3: 'test'}
>>> a = dict.fromkeys([1,2,3],[])
>>> a[1].append('test')
>>> a
{1: ['test'], 2: ['test'], 3: ['test']}

　　　　（8）copy：dict字典里还自带了copy方法，但是这里的copy是浅拷贝，只copy字典的第一层内容。定义了dic字典，dic2是dic的copy，当我们修改dic的时候，我们就发现dic2特跟着贱贱的变了，这就是浅拷贝，只是浅浅的copy了一下，剩下的就直接把指针copy了，事实上还是指向了dic字典中的list地址。

>>> dic
{'name': 'Eva', 'otherInfo': {'hobby': ['sing', 'teaism']}, 'gender': 'female', 'age': 18}
>>> dic2 = dic.copy()
>>> dic2
{'gender': 'female', 'age': 18, 'name': 'Eva', 'otherInfo': {'hobby': ['sing', 'teaism']}}
>>> hobbylst = ['sing','teaism', 'tourism','jogging']
>>> dic
{'name': 'Eva', 'otherInfo': {'hobby': ['sing', 'teaism']}, 'gender': 'female', 'age': 18}
>>> dic2
{'gender': 'female', 'age': 18, 'name': 'Eva', 'otherInfo': {'hobby': ['sing', 'teaism']}}