Python 基础之基本数据类型
首先，Python中的变量不需要声明。每个变量在使用前都必须赋值，变量赋值以后该变量才会被创建。在Python中，变量就是变量，它没有类型，我们所说的“类型”是变量所指的内存中对象的类型。Python 3中有六个标准的数据类型：
Numbers（数字）
class int(object): """ int(x=0) -> int or long int(x, base=10) -> int or long Convert a number or string to an integer, or return 0 if no arguments are given. If x is floating point, the conversion truncates towards zero. If x is outside the integer range, the function returns a long instead. If x is not a number or if base is given, then x must be a string or Unicode object representing an integer literal in the given base. The literal can be preceded by '+' or '-' and be surrounded by whitespace. The base defaults to 10. Valid bases are 0 and 2-36. Base 0 means to interpret the base from the string as an integer literal. >>> int('0b100', base=0) """ def bit_length(self): """ 返回表示该数字的时占用的最少位数 """ """ int.bit_length() -> int Number of bits necessary to represent self in binary. >>> bin(37) '0b100101' >>> (37).bit_length() """ return 0 def conjugate(self, *args, **kwargs): # real signature unknown """ 返回该复数的共轭复数 """ """ Returns self, the complex conjugate of any int. """ pass def __abs__(self): """ 返回绝对值 """ """ x.__abs__() <==> abs(x) """ pass def __add__(self, y): """ x.__add__(y) <==> x+y """ pass def __and__(self, y): """ x.__and__(y) <==> x&y """ pass def __cmp__(self, y): """ 比较两个数大小 """ """ x.__cmp__(y) <==> cmp(x,y) """ pass def __coerce__(self, y): """ 强制生成一个元组 """ """ x.__coerce__(y) <==> coerce(x, y) """ pass def __divmod__(self, y): """ 相除，得到商和余数组成的元组 """ """ x.__divmod__(y) <==> divmod(x, y) """ pass def __div__(self, y): """ x.__div__(y) <==> x/y """ pass def __float__(self): """ 转换为浮点类型 """ """ x.__float__() <==> float(x) """ pass def __floordiv__(self, y): """ x.__floordiv__(y) <==> x//y """ pass def __format__(self, *args, **kwargs): # real signature unknown pass def __getattribute__(self, name): """ x.__getattribute__('name') <==> x.name """ pass def __getnewargs__(self, *args, **kwargs): # real signature unknown """ 内部调用 __new__方法或创建对象时传入参数使用 """ pass def __hash__(self): """如果对象object为哈希表类型，返回对象object的哈希值。哈希值为整数。在字典查找中，哈希值用于快速比较字典的键。两个数值如果相等，则哈希值也相等。""" """ x.__hash__() <==> hash(x) """ pass def __hex__(self): """ 返回当前数的 十六进制 表示 """ """ x.__hex__() <==> hex(x) """ pass def __index__(self): """ 用于切片，数字无意义 """ """ x[y:z] <==> x[y.__index__():z.__index__()] """ pass def __init__(self, x, base=10): # known special case of int.__init__ """ 构造方法，执行 x = 123 或 x = int(10) 时，自动调用，暂时忽略 """ """ int(x=0) -> int or long int(x, base=10) -> int or long Convert a number or string to an integer, or return 0 if no arguments are given. If x is floating point, the conversion truncates towards zero. If x is outside the integer range, the function returns a long instead. If x is not a number or if base is given, then x must be a string or Unicode object representing an integer literal in the given base. The literal can be preceded by '+' or '-' and be surrounded by whitespace. The base defaults to 10. Valid bases are 0 and 2-36. Base 0 means to interpret the base from the string as an integer literal. >>> int('0b100', base=0) # (copied from class doc) """ pass def __int__(self): """ 转换为整数 """ """ x.__int__() <==> int(x) """ pass def __invert__(self): """ x.__invert__() <==> ~x """ pass def __long__(self): """ 转换为长整数 """ """ x.__long__() <==> long(x) """ pass def __lshift__(self, y): """ x.__lshift__(y) <==> x<<y """ pass def __mod__(self, y): """ x.__mod__(y) <==> x%y """ pass def __mul__(self, y): """ x.__mul__(y) <==> x*y """ pass def __neg__(self): """ x.__neg__() <==> -x """ pass @staticmethod # known case of __new__ def __new__(S, *more): """ T.__new__(S, ...) -> a new object with type S, a subtype of T """ pass def __nonzero__(self): """ x.__nonzero__() <==> x != 0 """ pass def __oct__(self): """ 返回改值的 八进制 表示 """ """ x.__oct__() <==> oct(x) """ pass def __or__(self, y): """ x.__or__(y) <==> x|y """ pass def __pos__(self): """ x.__pos__() <==> +x """ pass def __pow__(self, y, z=None): """ 幂，次方 """ """ x.__pow__(y[, z]) <==> pow(x, y[, z]) """ pass def __radd__(self, y): """ x.__radd__(y) <==> y+x """ pass def __rand__(self, y): """ x.__rand__(y) <==> y&x """ pass def __rdivmod__(self, y): """ x.__rdivmod__(y) <==> divmod(y, x) """ pass def __rdiv__(self, y): """ x.__rdiv__(y) <==> y/x """ pass def __repr__(self): """转化为解释器可读取的形式 """ """ x.__repr__() <==> repr(x) """ pass def __str__(self): """转换为人阅读的形式，如果没有适于人阅读的解释形式的话，则返回解释器课阅读的形式""" """ x.__str__() <==> str(x) """ pass def __rfloordiv__(self, y): """ x.__rfloordiv__(y) <==> y//x """ pass def __rlshift__(self, y): """ x.__rlshift__(y) <==> y<<x """ pass def __rmod__(self, y): """ x.__rmod__(y) <==> y%x """ pass def __rmul__(self, y): """ x.__rmul__(y) <==> y*x """ pass def __ror__(self, y): """ x.__ror__(y) <==> y|x """ pass def __rpow__(self, x, z=None): """ y.__rpow__(x[, z]) <==> pow(x, y[, z]) """ pass def __rrshift__(self, y): """ x.__rrshift__(y) <==> y>>x """ pass def __rshift__(self, y): """ x.__rshift__(y) <==> x>>y """ pass def __rsub__(self, y): """ x.__rsub__(y) <==> y-x """ pass def __rtruediv__(self, y): """ x.__rtruediv__(y) <==> y/x """ pass def __rxor__(self, y): """ x.__rxor__(y) <==> y^x """ pass def __sub__(self, y): """ x.__sub__(y) <==> x-y """ pass def __truediv__(self, y): """ x.__truediv__(y) <==> x/y """ pass def __trunc__(self, *args, **kwargs): """ 返回数值被截取为整形的值，在整形中无意义 """ pass def __xor__(self, y): """ x.__xor__(y) <==> x^y """ pass denominator = property(lambda self: object(), lambda self, v: None, lambda self: None) # default """ 分母 = 1 """ """the denominator of a rational number in lowest terms""" imag = property(lambda self: object(), lambda self, v: None, lambda self: None) # default """ 虚数，无意义 """ """the imaginary part of a complex number""" numerator = property(lambda self: object(), lambda self, v: None, lambda self: None) # default """ 分子 = 数字大小 """ """the numerator of a rational number in lowest terms""" real = property(lambda self: object(), lambda self, v: None, lambda self: None) # default """ 实属，无意义 """ """the real part of a complex number""" int
String（字符串）
class str(basestring): """ str(object='') -> string Return a nice string representation of the object. If the argument is a string, the return value is the same object. """ def capitalize(self): """ 首字母变大写 """ """ S.capitalize() -> string Return a copy of the string S with only its first character capitalized. """ return "" def center(self, width, fillchar=None): """ 内容居中，width：总长度；fillchar：空白处填充内容，默认无 """ """ S.center(width[, fillchar]) -> string Return S centered in a string of length width. Padding is done using the specified fill character (default is a space) """ return "" def count(self, sub, start=None, end=None): """ 子序列个数 """ """ S.count(sub[, start[, end]]) -> int Return the number of non-overlapping occurrences of substring sub in string S[start:end]. Optional arguments start and end are interpreted as in slice notation. """ return 0 def decode(self, encoding=None, errors=None): """ 解码 """ """ S.decode([encoding[,errors]]) -> object Decodes S using the codec registered for encoding. encoding defaults to the default encoding. errors may be given to set a different error handling scheme. Default is 'strict' meaning that encoding errors raise a UnicodeDecodeError. Other possible values are 'ignore' and 'replace' as well as any other name registered with codecs.register_error that is able to handle UnicodeDecodeErrors. """ return object() def encode(self, encoding=None, errors=None): """ 编码，针对unicode """ """ S.encode([encoding[,errors]]) -> object Encodes S using the codec registered for encoding. encoding defaults to the default encoding. errors may be given to set a different error handling scheme. Default is 'strict' meaning that encoding errors raise a UnicodeEncodeError. Other possible values are 'ignore', 'replace' and 'xmlcharrefreplace' as well as any other name registered with codecs.register_error that is able to handle UnicodeEncodeErrors. """ return object() def endswith(self, suffix, start=None, end=None): """ 是否以 xxx 结束 """ """ S.endswith(suffix[, start[, end]]) -> bool Return True if S ends with the specified suffix, False otherwise. With optional start, test S beginning at that position. With optional end, stop comparing S at that position. suffix can also be a tuple of strings to try. """ return False def expandtabs(self, tabsize=None): """ 将tab转换成空格，默认一个tab转换成8个空格 """ """ S.expandtabs([tabsize]) -> string Return a copy of S where all tab characters are expanded using spaces. If tabsize is not given, a tab size of 8 characters is assumed. """ return "" def find(self, sub, start=None, end=None): """ 寻找子序列位置，如果没找到，返回 -1 """ """ S.find(sub [,start [,end]]) -> int Return the lowest index in S where substring sub is found, such that sub is contained within S[start:end]. Optional arguments start and end are interpreted as in slice notation. Return -1 on failure. """ return 0 def format(*args, **kwargs): # known special case of str.format """ 字符串格式化，动态参数，将函数式编程时细说 """ """ S.format(*args, **kwargs) -> string Return a formatted version of S, using substitutions from args and kwargs. The substitutions are identified by braces ('{' and '}'). """ pass def index(self, sub, start=None, end=None): """ 子序列位置，如果没找到，报错 """ S.index(sub [,start [,end]]) -> int Like S.find() but raise ValueError when the substring is not found. """ return 0 def isalnum(self): """ 是否是字母和数字 """ """ S.isalnum() -> bool Return True if all characters in S are alphanumeric and there is at least one character in S, False otherwise. """ return False def isalpha(self): """ 是否是字母 """ """ S.isalpha() -> bool Return True if all characters in S are alphabetic and there is at least one character in S, False otherwise. """ return False def isdigit(self): """ 是否是数字 """ """ S.isdigit() -> bool Return True if all characters in S are digits and there is at least one character in S, False otherwise. """ return False def islower(self): """ 是否小写 """ """ S.islower() -> bool Return True if all cased characters in S are lowercase and there is at least one cased character in S, False otherwise. """ return False def isspace(self): """ S.isspace() -> bool Return True if all characters in S are whitespace and there is at least one character in S, False otherwise. """ return False def istitle(self): """ S.istitle() -> bool Return True if S is a titlecased string and there is at least one character in S, i.e. uppercase characters may only follow uncased characters and lowercase characters only cased ones. Return False otherwise. """ return False def isupper(self): """ S.isupper() -> bool Return True if all cased characters in S are uppercase and there is at least one cased character in S, False otherwise. """ return False def join(self, iterable): """ 连接 """ """ S.join(iterable) -> string Return a string which is the concatenation of the strings in the iterable. The separator between elements is S. """ return "" def ljust(self, width, fillchar=None): """ 内容左对齐，右侧填充 """ """ S.ljust(width[, fillchar]) -> string Return S left-justified in a string of length width. Padding is done using the specified fill character (default is a space). """ return "" def lower(self): """ 变小写 """ """ S.lower() -> string Return a copy of the string S converted to lowercase. """ return "" def lstrip(self, chars=None): """ 移除左侧空白 """ """ S.lstrip([chars]) -> string or unicode Return a copy of the string S with leading whitespace removed. If chars is given and not None, remove characters in chars instead. If chars is unicode, S will be converted to unicode before stripping """ return "" def partition(self, sep): """ 分割，前，中，后三部分 """ """ S.partition(sep) -> (head, sep, tail) Search for the separator sep in S, and return the part before it, the separator itself, and the part after it. If the separator is not found, return S and two empty strings. """ pass def replace(self, old, new, count=None): """ 替换 """ """ S.replace(old, new[, count]) -> string Return a copy of string S with all occurrences of substring old replaced by new. If the optional argument count is given, only the first count occurrences are replaced. """ return "" def rfind(self, sub, start=None, end=None): """ S.rfind(sub [,start [,end]]) -> int Return the highest index in S where substring sub is found, such that sub is contained within S[start:end]. Optional arguments start and end are interpreted as in slice notation. Return -1 on failure. """ return 0 def rindex(self, sub, start=None, end=None): """ S.rindex(sub [,start [,end]]) -> int Like S.rfind() but raise ValueError when the substring is not found. """ return 0 def rjust(self, width, fillchar=None): """ S.rjust(width[, fillchar]) -> string Return S right-justified in a string of length width. Padding is done using the specified fill character (default is a space) """ return "" def rpartition(self, sep): """ S.rpartition(sep) -> (head, sep, tail) Search for the separator sep in S, starting at the end of S, and return the part before it, the separator itself, and the part after it. If the separator is not found, return two empty strings and S. """ pass def rsplit(self, sep=None, maxsplit=None): """ S.rsplit([sep [,maxsplit]]) -> list of strings Return a list of the words in the string S, using sep as the delimiter string, starting at the end of the string and working to the front. If maxsplit is given, at most maxsplit splits are done. If sep is not specified or is None, any whitespace string is a separator. """ return [] def rstrip(self, chars=None): """ S.rstrip([chars]) -> string or unicode Return a copy of the string S with trailing whitespace removed. If chars is given and not None, remove characters in chars instead. If chars is unicode, S will be converted to unicode before stripping """ return "" def split(self, sep=None, maxsplit=None): """ 分割， maxsplit最多分割几次 """ """ S.split([sep [,maxsplit]]) -> list of strings Return a list of the words in the string S, using sep as the delimiter string. If maxsplit is given, at most maxsplit splits are done. If sep is not specified or is None, any whitespace string is a separator and empty strings are removed from the result. """ return [] def splitlines(self, keepends=False): """ 根据换行分割 """ """ S.splitlines(keepends=False) -> list of strings Return a list of the lines in S, breaking at line boundaries. Line breaks are not included in the resulting list unless keepends is given and true. """ return [] def startswith(self, prefix, start=None, end=None): """ 是否起始 """ """ S.startswith(prefix[, start[, end]]) -> bool Return True if S starts with the specified prefix, False otherwise. With optional start, test S beginning at that position. With optional end, stop comparing S at that position. prefix can also be a tuple of strings to try. """ return False def strip(self, chars=None): """ 移除两段空白 """ """ S.strip([chars]) -> string or unicode Return a copy of the string S with leading and trailing whitespace removed. If chars is given and not None, remove characters in chars instead. If chars is unicode, S will be converted to unicode before stripping """ return "" def swapcase(self): """ 大写变小写，小写变大写 """ """ S.swapcase() -> string Return a copy of the string S with uppercase characters converted to lowercase and vice versa. """ return "" def title(self): """ S.title() -> string Return a titlecased version of S, i.e. words start with uppercase characters, all remaining cased characters have lowercase. """ return "" def translate(self, table, deletechars=None): """ 转换，需要先做一个对应表，最后一个表示删除字符集合 intab = "aeiou" outtab = "12345" trantab = maketrans(intab, outtab) str = "this is string example....wow!!!" print str.translate(trantab, 'xm') """ """ S.translate(table [,deletechars]) -> string Return a copy of the string S, where all characters occurring in the optional argument deletechars are removed, and the remaining characters have been mapped through the given translation table, which must be a string of length 256 or None. If the table argument is None, no translation is applied and the operation simply removes the characters in deletechars. """ return "" def upper(self): """ S.upper() -> string Return a copy of the string S converted to uppercase. """ return "" def zfill(self, width): """方法返回指定长度的字符串，原字符串右对齐，前面填充0。""" """ S.zfill(width) -> string Pad a numeric string S with zeros on the left, to fill a field of the specified width. The string S is never truncated. """ return "" def _formatter_field_name_split(self, *args, **kwargs): # real signature unknown pass def _formatter_parser(self, *args, **kwargs): # real signature unknown pass def __add__(self, y): """ x.__add__(y) <==> x+y """ pass def __contains__(self, y): """ x.__contains__(y) <==> y in x """ pass def __eq__(self, y): """ x.__eq__(y) <==> x==y """ pass def __format__(self, format_spec): """ S.__format__(format_spec) -> string Return a formatted version of S as described by format_spec. """ return "" def __getattribute__(self, name): """ x.__getattribute__('name') <==> x.name """ pass def __getitem__(self, y): """ x.__getitem__(y) <==> x[y] """ pass def __getnewargs__(self, *args, **kwargs): # real signature unknown pass def __getslice__(self, i, j): """ x.__getslice__(i, j) <==> x[i:j] Use of negative indices is not supported. """ pass def __ge__(self, y): """ x.__ge__(y) <==> x>=y """ pass def __gt__(self, y): """ x.__gt__(y) <==> x>y """ pass def __hash__(self): """ x.__hash__() <==> hash(x) """ pass def __init__(self, string=''): # known special case of str.__init__ """ str(object='') -> string Return a nice string representation of the object. If the argument is a string, the return value is the same object. # (copied from class doc) """ pass def __len__(self): """ x.__len__() <==> len(x) """ pass def __le__(self, y): """ x.__le__(y) <==> x<=y """ pass def __lt__(self, y): """ x.__lt__(y) <==> x<y """ pass def __mod__(self, y): """ x.__mod__(y) <==> x%y """ pass def __mul__(self, n): """ x.__mul__(n) <==> x*n """ pass @staticmethod # known case of __new__ def __new__(S, *more): """ T.__new__(S, ...) -> a new object with type S, a subtype of T """ pass def __ne__(self, y): """ x.__ne__(y) <==> x!=y """ pass def __repr__(self): """ x.__repr__() <==> repr(x) """ pass def __rmod__(self, y): """ x.__rmod__(y) <==> y%x """ pass def __rmul__(self, n): """ x.__rmul__(n) <==> n*x """ pass def __sizeof__(self): """ S.__sizeof__() -> size of S in memory, in bytes """ pass def __str__(self): """ x.__str__() <==> str(x) """ pass str
List（列表）
1 class list(object): 2 """ 3 list() -> new empty list 4 list(iterable) -> new list initialized from iterable's items 5 """ 6 def append(self, p_object): # real signature unknown; restored from __doc__ 7 """ L.append(object) -- append object to end """ 8 pass 9 10 def count(self, value): # real signature unknown; restored from __doc__ 11 """ L.count(value) -> integer -- return number of occurrences of value """ 12 return 0 13 14 def extend(self, iterable): # real signature unknown; restored from __doc__ 15 """ L.extend(iterable) -- extend list by appending elements from the iterable """ 16 pass 17 18 def index(self, value, start=None, stop=None): # real signature unknown; restored from __doc__ 19 """ 20 L.index(value, [start, [stop]]) -> integer -- return first index of value. 21 Raises ValueError if the value is not present. 22 """ 23 return 0 24 25 def insert(self, index, p_object): # real signature unknown; restored from __doc__ 26 """ L.insert(index, object) -- insert object before index """ 27 pass 28 29 def pop(self, index=None): # real signature unknown; restored from __doc__ 30 """ 31 L.pop([index]) -> item -- remove and return item at index (default last). 32 Raises IndexError if list is empty or index is out of range. 33 """ 34 pass 35 36 def remove(self, value): # real signature unknown; restored from __doc__ 37 """ 38 L.remove(value) -- remove first occurrence of value. 39 Raises ValueError if the value is not present. 40 """ 41 pass 42 43 def reverse(self): # real signature unknown; restored from __doc__ 44 """ L.reverse() -- reverse *IN PLACE* """ 45 pass 46 47 def sort(self, cmp=None, key=None, reverse=False): # real signature unknown; restored from __doc__ 48 """ 49 L.sort(cmp=None, key=None, reverse=False) -- stable sort *IN PLACE*; 50 cmp(x, y) -> -1, 0, 1 51 """ 52 pass 53 54 def __add__(self, y): # real signature unknown; restored from __doc__ 55 """ x.__add__(y) <==> x+y """ 56 pass 57 58 def __contains__(self, y): # real signature unknown; restored from __doc__ 59 """ x.__contains__(y) <==> y in x """ 60 pass 61 62 def __delitem__(self, y): # real signature unknown; restored from __doc__ 63 """ x.__delitem__(y) <==> del x[y] """ 64 pass 65 66 def __delslice__(self, i, j): # real signature unknown; restored from __doc__ 67 """ 68 x.__delslice__(i, j) <==> del x[i:j] 69 70 Use of negative indices is not supported. 71 """ 72 pass 73 74 def __eq__(self, y): # real signature unknown; restored from __doc__ 75 """ x.__eq__(y) <==> x==y """ 76 pass 77 78 def __getattribute__(self, name): # real signature unknown; restored from __doc__ 79 """ x.__getattribute__('name') <==> x.name """ 80 pass 81 82 def __getitem__(self, y): # real signature unknown; restored from __doc__ 83 """ x.__getitem__(y) <==> x[y] """ 84 pass 85 86 def __getslice__(self, i, j): # real signature unknown; restored from __doc__ 87 """ 88 x.__getslice__(i, j) <==> x[i:j] 89 90 Use of negative indices is not supported. 91 """ 92 pass 93 94 def __ge__(self, y): # real signature unknown; restored from __doc__ 95 """ x.__ge__(y) <==> x>=y """ 96 pass 97 98 def __gt__(self, y): # real signature unknown; restored from __doc__ 99 """ x.__gt__(y) <==> x>y """ 100 pass 101 102 def __iadd__(self, y): # real signature unknown; restored from __doc__ 103 """ x.__iadd__(y) <==> x+=y """ 104 pass 105 106 def __imul__(self, y): # real signature unknown; restored from __doc__ 107 """ x.__imul__(y) <==> x*=y """ 108 pass 109 110 def __init__(self, seq=()): # known special case of list.__init__ 111 """ 112 list() -> new empty list 113 list(iterable) -> new list initialized from iterable's items 114 # (copied from class doc) 115 """ 116 pass 117 118 def __iter__(self): # real signature unknown; restored from __doc__ 119 """ x.__iter__() <==> iter(x) """ 120 pass 121 122 def __len__(self): # real signature unknown; restored from __doc__ 123 """ x.__len__() <==> len(x) """ 124 pass 125 126 def __le__(self, y): # real signature unknown; restored from __doc__ 127 """ x.__le__(y) <==> x<=y """ 128 pass 129 130 def __lt__(self, y): # real signature unknown; restored from __doc__ 131 """ x.__lt__(y) <==> x<y """ 132 pass 133 134 def __mul__(self, n): # real signature unknown; restored from __doc__ 135 """ x.__mul__(n) <==> x*n """ 136 pass 137 138 @staticmethod # known case of __new__ 139 def __new__(S, *more): # real signature unknown; restored from __doc__ 140 """ T.__new__(S, ...) -> a new object with type S, a subtype of T """ 141 pass 142 143 def __ne__(self, y): # real signature unknown; restored from __doc__ 144 """ x.__ne__(y) <==> x!=y """ 145 pass 146 147 def __repr__(self): # real signature unknown; restored from __doc__ 148 """ x.__repr__() <==> repr(x) """ 149 pass 150 151 def __reversed__(self): # real signature unknown; restored from __doc__ 152 """ L.__reversed__() -- return a reverse iterator over the list """ 153 pass 154 155 def __rmul__(self, n): # real signature unknown; restored from __doc__ 156 """ x.__rmul__(n) <==> n*x """ 157 pass 158 159 def __setitem__(self, i, y): # real signature unknown; restored from __doc__ 160 """ x.__setitem__(i, y) <==> x[i]=y """ 161 pass 162 163 def __setslice__(self, i, j, y): # real signature unknown; restored from __doc__ 164 """ 165 x.__setslice__(i, j, y) <==> x[i:j]=y 166 167 Use of negative indices is not supported. 168 """ 169 pass 170 171 def __sizeof__(self): # real signature unknown; restored from __doc__ 172 """ L.__sizeof__() -- size of L in memory, in bytes """ 173 pass 174 175 __hash__ = None 176 177 list
Tuple（元组）
lass tuple(object): """ tuple() -> empty tuple tuple(iterable) -> tuple initialized from iterable's items If the argument is a tuple, the return value is the same object. """ def count(self, value): # real signature unknown; restored from __doc__ """ T.count(value) -> integer -- return number of occurrences of value """ return 0 def index(self, value, start=None, stop=None): # real signature unknown; restored from __doc__ """ T.index(value, [start, [stop]]) -> integer -- return first index of value. Raises ValueError if the value is not present. """ return 0 def __add__(self, y): # real signature unknown; restored from __doc__ """ x.__add__(y) <==> x+y """ pass def __contains__(self, y): # real signature unknown; restored from __doc__ """ x.__contains__(y) <==> y in x """ pass def __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 __getnewargs__(self, *args, **kwargs): # real signature unknown 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 __hash__(self): # real signature unknown; restored from __doc__ """ x.__hash__() <==> hash(x) """ pass def __init__(self, seq=()): # known special case of tuple.__init__ """ tuple() -> empty tuple tuple(iterable) -> tuple initialized from iterable's items If the argument is a tuple, the return value is the same object. # (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 __rmul__(self, n): # real signature unknown; restored from __doc__ """ x.__rmul__(n) <==> n*x """ pass def __sizeof__(self): # real signature unknown; restored from __doc__ """ T.__sizeof__() -- size of T in memory, in bytes """ pass tuple
Sets（集合）
Dictionaries（字典）
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
本文主要先介绍这几种数据类型的定义和它们之间的联系与区别。
一、Numbers
Python 3支持int、float、bool、complex（复数）。数值类型的赋值和计算都是很直观的，就像大多数语言一样。内置的type()函数可以用来查询变量所指的对象类型。
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>>> a, b, c, d = 20, 5.5, True, 4+3j>>> print(type(a), type(b), type(c), type(d))<class 'int'> <class 'float'> <class 'bool'> <class 'complex'> |
数值运算：
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>>> 5 + 4 # 加法9>>> 4.3 - 2 # 减法2.3>>> 3 * 7 # 乘法21>>> 2 / 4 # 除法，得到一个浮点数0.5>>> 2 // 4 # 除法，得到一个整数0>>> 17 % 3 # 取余 2>>> 2 ** 5 # 乘方32 |
要点：
1、Python可以同时为多个变量赋值，如a, b = 1, 2。
2、一个变量通过赋值可以指向不同类型的对象。
3、数值的除法（/）总是返回一个浮点数，要获取整数使用//操作符。
4、在混合计算时，Pyhton会把整型转换成为浮点数。
二、Strings
Python中的字符串str用单引号(‘ ')或双引号(“ ”)括起来，同时使用反斜杠(\)转义特殊字符。
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>>> s = 'Yes,he doesn\'t'>>> print(s, type(s), len(s))Yes,he doesn't <class 'str'> 14 |
如果你不想让反斜杠发生转义，可以在字符串前面添加一个r，表示原始字符串：
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>>> print('C:\some\name')C:\someame>>> print(r'C:\some\name')C:\some\name |
另外，反斜杠可以作为续行符，表示下一行是上一行的延续。还可以使用"""..."""或者'''...'''跨越多行。
字符串可以使用 + 运算符串连接在一起，或者用 * 运算符重复：
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>>> print('str'+'ing', 'my'*3)string mymymy |
Python中的字符串有两种索引方式，第一种是从左往右，从0开始依次增加；第二种是从右往左，从-1开始依次减少。注意，没有单独的字符类型，一个字符就是长度为1的字符串。
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>>> word = 'Python'>>> print(word[0], word[5])P n>>> print(word[-1], word[-6])n P |
还可以对字符串进行切片，获取一段子串。用冒号分隔两个索引，形式为变量[头下标:尾下标]。截取的范围是前闭后开的，并且两个索引都可以省略：
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>>> word = 'ilovepython'>>> word[1:5]'love'>>> word[:]'ilovepython'>>> word[5:]'python'>>> word[-10:-6]'love' |
与C字符串不同的是，Python字符串不能被改变。向一个索引位置赋值，比如word[0] = 'm'会导致错误。
要点：
1、反斜杠可以用来转义，使用r可以让反斜杠不发生转义。
2、字符串可以用+运算符连接在一起，用*运算符重复。
3、Python中的字符串有两种索引方式，从左往右以0开始，从右往左以-1开始。
4、Python中的字符串不能改变。
三、List
List（列表） 是 Python 中使用最频繁的数据类型。列表是写在方括号之间、用逗号分隔开的元素列表。列表中元素的类型可以不相同：
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>>> a = ['him', 25, 100, 'her'] >>> print(a, type(a), len(a))['him', 25, 100, 'her'] <class 'list'> 4 |
和字符串一样，列表同样可以被索引和切片，列表被切片后返回一个包含所需元素的新列表。详细的在这里就不赘述了。
列表还支持串联操作，使用+操作符：
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>>> a = [1, 2, 3, 4, 5]>>> a + [6, 7, 8][1, 2, 3, 4, 5, 6, 7, 8] |
与Python字符串不同的是，列表中的元素是可以改变的：
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>>> a = [1, 2, 3, 4, 5, 6]>>> a[0] = 9>>> a[2:5] = [13, 14, 15]>>> a[9, 2, 13, 14, 15, 6]>>> a[2:5] = [] # 删除>>> a[9, 2, 6] |
List内置了有很多方法，例如append()、pop()等等，这在后面会讲到。
要点：
1、List写在方括号之间，元素用逗号隔开。
2、和字符串一样，list可以被索引和切片。
3、List可以使用+操作符进行拼接。
4、List中的元素是可以改变的。
四、Tuple
元组（tuple）与列表类似，不同之处在于元组的元素不能修改。元组是写在小括号之间、用逗号隔开的元素列表。元组中的元素类型也可以不相同：
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>>> a = (1991, 2014, 'physics', 'math')>>> print(a, type(a), len(a))(1991, 2014, 'physics', 'math') <class 'tuple'> 4 |
元组与字符串类似，可以被索引且下标索引从0开始，也可以进行截取/切片（看上面，这里不再赘述）。其实，可以把字符串看作一种特殊的元组。
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>>> tup = (1, 2, 3, 4, 5, 6)>>> print(tup[0], tup[1:5])1 (2, 3, 4, 5)>>> tup[0] = 11 # 修改元组元素的操作是非法的 |
虽然tuple的元素不可改变，但它可以包含可变的对象，比如list列表。
构造包含0个或1个元素的tuple是个特殊的问题，所以有一些额外的语法规则：
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tup1 = () # 空元组tup2 = (20,) # 一个元素，需要在元素后添加逗号 |
另外，元组也支持用+操作符：
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>>> tup1, tup2 = (1, 2, 3), (4, 5, 6)>>> print(tup1+tup2)(1, 2, 3, 4, 5, 6) |
string、list和tuple都属于sequence（序列）。
要点：
1、与字符串一样，元组的元素不能修改。
2、元组也可以被索引和切片，方法一样。
3、注意构造包含0或1个元素的元组的特殊语法规则。
4、元组也可以使用+操作符进行拼接。
五、Sets
集合（set）是一个无序不重复元素的集。基本功能是进行成员关系测试和消除重复元素。可以使用大括号或者set()函数创建set集合，注意：创建一个空集合必须用 set() 而不是 { }，因为{ }是用来创建一个空字典。
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>>> student = {'Tom', 'Jim', 'Mary', 'Tom', 'Jack', 'Rose'}>>> print(student) # 重复的元素被自动去掉{'Jim', 'Jack', 'Mary', 'Tom', 'Rose'}>>> 'Rose' in student # membership testing（成员测试）True>>> # set可以进行集合运算... >>> a = set('abracadabra')>>> b = set('alacazam')>>> a{'a', 'b', 'c', 'd', 'r'}>>> a - b # a和b的差集{'b', 'd', 'r'}>>> a | b # a和b的并集{'l', 'm', 'a', 'b', 'c', 'd', 'z', 'r'}>>> a & b # a和b的交集{'a', 'c'}>>> a ^ b # a和b中不同时存在的元素{'l', 'm', 'b', 'd', 'z', 'r'} |
要点：
1、set集合中的元素不重复，重复了它会自动去掉。
2、set集合可以用大括号或者set()函数创建，但空集合必须使用set()函数创建。
3、set集合可以用来进行成员测试、消除重复元素。
六、Dictionaries
字典（dictionary）是Python中另一个非常有用的内置数据类型。字典是一种映射类型（mapping type），它是一个无序的键 : 值对集合。关键字必须使用不可变类型，也就是说list和包含可变类型的tuple不能做关键字。在同一个字典中，关键字还必须互不相同。
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>>> dic = {} # 创建空字典>>> tel = {'Jack':1557, 'Tom':1320, 'Rose':1886}>>> tel{'Tom': 1320, 'Jack': 1557, 'Rose': 1886}>>> tel['Jack'] # 主要的操作：通过key查询1557>>> del tel['Rose'] # 删除一个键值对>>> tel['Mary'] = 4127 # 添加一个键值对>>> tel{'Tom': 1320, 'Jack': 1557, 'Mary': 4127}>>> list(tel.keys()) # 返回所有key组成的list['Tom', 'Jack', 'Mary']>>> sorted(tel.keys()) # 按key排序['Jack', 'Mary', 'Tom']>>> 'Tom' in tel # 成员测试True>>> 'Mary' not in tel # 成员测试False |
构造函数 dict() 直接从键值对sequence中构建字典，当然也可以进行推导，如下：
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>>> dict([('sape', 4139), ('guido', 4127), ('jack', 4098)]){'jack': 4098, 'sape': 4139, 'guido': 4127}>>> {x: x**2 for x in (2, 4, 6)}{2: 4, 4: 16, 6: 36}>>> dict(sape=4139, guido=4127, jack=4098){'jack': 4098, 'sape': 4139, 'guido': 4127} |
另外，字典类型也有一些内置的函数，例如clear()、keys()、values()等。
要点：
1、字典是一种映射类型，它的元素是键值对。
2、字典的关键字必须为不可变类型，且不能重复。
3、创建空字典使用{ }。
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