Python之路【第二篇】：Python基礎（一）

入門知識拾遺

一、作用域

對于變量的作用域，執行聲明并在內存中存在，該變量就可以在下面的代碼中使用。

1 2 3

if?1==1: ????name?=?'wupeiqi' print??name

下面的結論對嗎？

外層變量，可以被內層變量使用 內層變量，無法被外層變量使用

二、三元運算

1	result?=?值1?if?條件?else?值2

如果條件為真：result = 值1
如果條件為假：result = 值2

三、進制

• 二進制，01
• 八進制，01234567
• 十進制，0123456789
• 十六進制，0123456789ABCDEF

Python基礎

對于Python，一切事物都是對象，對象基于類創建

所以，以下這些值都是對象： "wupeiqi"、38、['北京', '上海', '深圳']，并且是根據不同的類生成的對象。

一、整數

如： 18、73、84

每一個整數都具備如下功能：

class int(object):"""int(x=0) -> int or longint(x, base=10) -> int or longConvert a number or string to an integer, or return 0 if no argumentsare 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 orUnicode object representing an integer literal in the given base. Theliteral 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 tointerpret the base from the string as an integer literal.>>> int('0b100', base=0)4"""def bit_length(self): """ 返回表示該數字的時占用的最少位數 """"""int.bit_length() -> intNumber of bits necessary to represent self in binary.>>> bin(37)'0b100101'>>> (37).bit_length()6"""return 0def conjugate(self, *args, **kwargs): # real signature unknown""" 返回該復數的共軛復數 """""" Returns self, the complex conjugate of any int. """passdef __abs__(self):""" 返回絕對值 """""" x.__abs__() <==> abs(x) """passdef __add__(self, y):""" x.__add__(y) <==> x+y """passdef __and__(self, y):""" x.__and__(y) <==> x&y """passdef __cmp__(self, y): """ 比較兩個數大小 """""" x.__cmp__(y) <==> cmp(x,y) """passdef __coerce__(self, y):""" 強制生成一個元組 """ """ x.__coerce__(y) <==> coerce(x, y) """passdef __divmod__(self, y): """ 相除，得到商和余數組成的元組 """ """ x.__divmod__(y) <==> divmod(x, y) """passdef __div__(self, y): """ x.__div__(y) <==> x/y """passdef __float__(self): """ 轉換為浮點類型 """ """ x.__float__() <==> float(x) """passdef __floordiv__(self, y): """ x.__floordiv__(y) <==> x//y """passdef __format__(self, *args, **kwargs): # real signature unknownpassdef __getattribute__(self, name): """ x.__getattribute__('name') <==> x.name """passdef __getnewargs__(self, *args, **kwargs): # real signature unknown""" 內部調用 __new__方法或創建對象時傳入參數使用 """ passdef __hash__(self): """如果對象object為哈希表類型，返回對象object的哈希值。哈希值為整數。在字典查找中，哈希值用于快速比較字典的鍵。兩個數值如果相等，則哈希值也相等。"""""" x.__hash__() <==> hash(x) """passdef __hex__(self): """ 返回當前數的 十六進制 表示 """ """ x.__hex__() <==> hex(x) """passdef __index__(self): """ 用于切片，數字無意義 """""" x[y:z] <==> x[y.__index__():z.__index__()] """passdef __init__(self, x, base=10): # known special case of int.__init__""" 構造方法，執行 x = 123 或 x = int(10) 時，自動調用，暫時忽略 """ """int(x=0) -> int or longint(x, base=10) -> int or longConvert a number or string to an integer, or return 0 if no argumentsare 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 orUnicode object representing an integer literal in the given base. Theliteral 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 tointerpret the base from the string as an integer literal.>>> int('0b100', base=0)4# (copied from class doc)"""passdef __int__(self): """ 轉換為整數 """ """ x.__int__() <==> int(x) """passdef __invert__(self): """ x.__invert__() <==> ~x """passdef __long__(self): """ 轉換為長整數 """ """ x.__long__() <==> long(x) """passdef __lshift__(self, y): """ x.__lshift__(y) <==> x<<y """passdef __mod__(self, y): """ x.__mod__(y) <==> x%y """passdef __mul__(self, y): """ x.__mul__(y) <==> x*y """passdef __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 """passdef __nonzero__(self): """ x.__nonzero__() <==> x != 0 """passdef __oct__(self): """ 返回改值的 八進制 表示 """ """ x.__oct__() <==> oct(x) """passdef __or__(self, y): """ x.__or__(y) <==> x|y """passdef __pos__(self): """ x.__pos__() <==> +x """passdef __pow__(self, y, z=None): """ 冪，次方 """ """ x.__pow__(y[, z]) <==> pow(x, y[, z]) """passdef __radd__(self, y): """ x.__radd__(y) <==> y+x """passdef __rand__(self, y): """ x.__rand__(y) <==> y&x """passdef __rdivmod__(self, y): """ x.__rdivmod__(y) <==> divmod(y, x) """passdef __rdiv__(self, y): """ x.__rdiv__(y) <==> y/x """passdef __repr__(self): """轉化為解釋器可讀取的形式 """""" x.__repr__() <==> repr(x) """passdef __str__(self): """轉換為人閱讀的形式，如果沒有適于人閱讀的解釋形式的話，則返回解釋器課閱讀的形式"""""" x.__str__() <==> str(x) """passdef __rfloordiv__(self, y): """ x.__rfloordiv__(y) <==> y//x """passdef __rlshift__(self, y): """ x.__rlshift__(y) <==> y<<x """passdef __rmod__(self, y): """ x.__rmod__(y) <==> y%x """passdef __rmul__(self, y): """ x.__rmul__(y) <==> y*x """passdef __ror__(self, y): """ x.__ror__(y) <==> y|x """passdef __rpow__(self, x, z=None): """ y.__rpow__(x[, z]) <==> pow(x, y[, z]) """passdef __rrshift__(self, y): """ x.__rrshift__(y) <==> y>>x """passdef __rshift__(self, y): """ x.__rshift__(y) <==> x>>y """passdef __rsub__(self, y): """ x.__rsub__(y) <==> y-x """passdef __rtruediv__(self, y): """ x.__rtruediv__(y) <==> y/x """passdef __rxor__(self, y): """ x.__rxor__(y) <==> y^x """passdef __sub__(self, y): """ x.__sub__(y) <==> x-y """passdef __truediv__(self, y): """ x.__truediv__(y) <==> x/y """passdef __trunc__(self, *args, **kwargs): """ 返回數值被截取為整形的值，在整形中無意義 """passdef __xor__(self, y): """ x.__xor__(y) <==> x^y """passdenominator = 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""" 虛數，無意義 """"""the imaginary part of a complex number"""numerator = property(lambda self: object(), lambda self, v: None, lambda self: None) # default""" 分子 = 數字大小 """"""the numerator of a rational number in lowest terms"""real = property(lambda self: object(), lambda self, v: None, lambda self: None) # default""" 實屬，無意義 """"""the real part of a complex number"""

二、長整型

可能如：2147483649、9223372036854775807

每個長整型都具備如下功能：

class long(object):"""long(x=0) -> longlong(x, base=10) -> longConvert a number or string to a long integer, or return 0L if no argumentsare given. If x is floating point, the conversion truncates towards zero.If x is not a number or if base is given, then x must be a string orUnicode object representing an integer literal in the given base. Theliteral 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 tointerpret the base from the string as an integer literal.>>> int('0b100', base=0)4L"""def bit_length(self): # real signature unknown; restored from __doc__"""long.bit_length() -> int or longNumber of bits necessary to represent self in binary.>>> bin(37L)'0b100101'>>> (37L).bit_length()6"""return 0def conjugate(self, *args, **kwargs): # real signature unknown""" Returns self, the complex conjugate of any long. """passdef __abs__(self): # real signature unknown; restored from __doc__""" x.__abs__() <==> abs(x) """passdef __add__(self, y): # real signature unknown; restored from __doc__""" x.__add__(y) <==> x+y """passdef __and__(self, y): # real signature unknown; restored from __doc__""" x.__and__(y) <==> x&y """passdef __cmp__(self, y): # real signature unknown; restored from __doc__""" x.__cmp__(y) <==> cmp(x,y) """passdef __coerce__(self, y): # real signature unknown; restored from __doc__""" x.__coerce__(y) <==> coerce(x, y) """passdef __divmod__(self, y): # real signature unknown; restored from __doc__""" x.__divmod__(y) <==> divmod(x, y) """passdef __div__(self, y): # real signature unknown; restored from __doc__""" x.__div__(y) <==> x/y """passdef __float__(self): # real signature unknown; restored from __doc__""" x.__float__() <==> float(x) """passdef __floordiv__(self, y): # real signature unknown; restored from __doc__""" x.__floordiv__(y) <==> x//y """passdef __format__(self, *args, **kwargs): # real signature unknownpassdef __getattribute__(self, name): # real signature unknown; restored from __doc__""" x.__getattribute__('name') <==> x.name """passdef __getnewargs__(self, *args, **kwargs): # real signature unknownpassdef __hash__(self): # real signature unknown; restored from __doc__""" x.__hash__() <==> hash(x) """passdef __hex__(self): # real signature unknown; restored from __doc__""" x.__hex__() <==> hex(x) """passdef __index__(self): # real signature unknown; restored from __doc__""" x[y:z] <==> x[y.__index__():z.__index__()] """passdef __init__(self, x=0): # real signature unknown; restored from __doc__passdef __int__(self): # real signature unknown; restored from __doc__""" x.__int__() <==> int(x) """passdef __invert__(self): # real signature unknown; restored from __doc__""" x.__invert__() <==> ~x """passdef __long__(self): # real signature unknown; restored from __doc__""" x.__long__() <==> long(x) """passdef __lshift__(self, y): # real signature unknown; restored from __doc__""" x.__lshift__(y) <==> x<<y """passdef __mod__(self, y): # real signature unknown; restored from __doc__""" x.__mod__(y) <==> x%y """passdef __mul__(self, y): # real signature unknown; restored from __doc__""" x.__mul__(y) <==> x*y """passdef __neg__(self): # real signature unknown; restored from __doc__""" x.__neg__() <==> -x """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 """passdef __nonzero__(self): # real signature unknown; restored from __doc__""" x.__nonzero__() <==> x != 0 """passdef __oct__(self): # real signature unknown; restored from __doc__""" x.__oct__() <==> oct(x) """passdef __or__(self, y): # real signature unknown; restored from __doc__""" x.__or__(y) <==> x|y """passdef __pos__(self): # real signature unknown; restored from __doc__""" x.__pos__() <==> +x """passdef __pow__(self, y, z=None): # real signature unknown; restored from __doc__""" x.__pow__(y[, z]) <==> pow(x, y[, z]) """passdef __radd__(self, y): # real signature unknown; restored from __doc__""" x.__radd__(y) <==> y+x """passdef __rand__(self, y): # real signature unknown; restored from __doc__""" x.__rand__(y) <==> y&x """passdef __rdivmod__(self, y): # real signature unknown; restored from __doc__""" x.__rdivmod__(y) <==> divmod(y, x) """passdef __rdiv__(self, y): # real signature unknown; restored from __doc__""" x.__rdiv__(y) <==> y/x """passdef __repr__(self): # real signature unknown; restored from __doc__""" x.__repr__() <==> repr(x) """passdef __rfloordiv__(self, y): # real signature unknown; restored from __doc__""" x.__rfloordiv__(y) <==> y//x """passdef __rlshift__(self, y): # real signature unknown; restored from __doc__""" x.__rlshift__(y) <==> y<<x """passdef __rmod__(self, y): # real signature unknown; restored from __doc__""" x.__rmod__(y) <==> y%x """passdef __rmul__(self, y): # real signature unknown; restored from __doc__""" x.__rmul__(y) <==> y*x """passdef __ror__(self, y): # real signature unknown; restored from __doc__""" x.__ror__(y) <==> y|x """passdef __rpow__(self, x, z=None): # real signature unknown; restored from __doc__""" y.__rpow__(x[, z]) <==> pow(x, y[, z]) """passdef __rrshift__(self, y): # real signature unknown; restored from __doc__""" x.__rrshift__(y) <==> y>>x """passdef __rshift__(self, y): # real signature unknown; restored from __doc__""" x.__rshift__(y) <==> x>>y """passdef __rsub__(self, y): # real signature unknown; restored from __doc__""" x.__rsub__(y) <==> y-x """passdef __rtruediv__(self, y): # real signature unknown; restored from __doc__""" x.__rtruediv__(y) <==> y/x """passdef __rxor__(self, y): # real signature unknown; restored from __doc__""" x.__rxor__(y) <==> y^x """passdef __sizeof__(self, *args, **kwargs): # real signature unknown""" Returns size in memory, in bytes """passdef __str__(self): # real signature unknown; restored from __doc__""" x.__str__() <==> str(x) """passdef __sub__(self, y): # real signature unknown; restored from __doc__""" x.__sub__(y) <==> x-y """passdef __truediv__(self, y): # real signature unknown; restored from __doc__""" x.__truediv__(y) <==> x/y """passdef __trunc__(self, *args, **kwargs): # real signature unknown""" Truncating an Integral returns itself. """passdef __xor__(self, y): # real signature unknown; restored from __doc__""" x.__xor__(y) <==> x^y """passdenominator = property(lambda self: object(), lambda self, v: None, lambda self: None) # default"""the denominator of a rational number in lowest terms"""imag = property(lambda self: object(), lambda self, v: None, lambda self: None) # default"""the imaginary part of a complex number"""numerator = property(lambda self: object(), lambda self, v: None, lambda self: None) # default"""the numerator of a rational number in lowest terms"""real = property(lambda self: object(), lambda self, v: None, lambda self: None) # default"""the real part of a complex number"""

三、浮點型

如：3.14、2.88

每個浮點型都具備如下功能：

class float(object):"""float(x) -> floating point numberConvert a string or number to a floating point number, if possible."""def as_integer_ratio(self): """ 獲取改值的最簡比 """"""float.as_integer_ratio() -> (int, int)Return a pair of integers, whose ratio is exactly equal to the originalfloat and with a positive denominator.Raise OverflowError on infinities and a ValueError on NaNs.>>> (10.0).as_integer_ratio()(10, 1)>>> (0.0).as_integer_ratio()(0, 1)>>> (-.25).as_integer_ratio()(-1, 4)"""passdef conjugate(self, *args, **kwargs): # real signature unknown""" Return self, the complex conjugate of any float. """passdef fromhex(self, string): """ 將十六進制字符串轉換成浮點型 """"""float.fromhex(string) -> floatCreate a floating-point number from a hexadecimal string.>>> float.fromhex('0x1.ffffp10')2047.984375>>> float.fromhex('-0x1p-1074')-4.9406564584124654e-324"""return 0.0def hex(self): """ 返回當前值的 16 進制表示 """"""float.hex() -> stringReturn a hexadecimal representation of a floating-point number.>>> (-0.1).hex()'-0x1.999999999999ap-4'>>> 3.14159.hex()'0x1.921f9f01b866ep+1'"""return ""def is_integer(self, *args, **kwargs): # real signature unknown""" Return True if the float is an integer. """passdef __abs__(self): """ x.__abs__() <==> abs(x) """passdef __add__(self, y): """ x.__add__(y) <==> x+y """passdef __coerce__(self, y): """ x.__coerce__(y) <==> coerce(x, y) """passdef __divmod__(self, y): """ x.__divmod__(y) <==> divmod(x, y) """passdef __div__(self, y): """ x.__div__(y) <==> x/y """passdef __eq__(self, y): """ x.__eq__(y) <==> x==y """passdef __float__(self): """ x.__float__() <==> float(x) """passdef __floordiv__(self, y): """ x.__floordiv__(y) <==> x//y """passdef __format__(self, format_spec): """float.__format__(format_spec) -> stringFormats the float according to format_spec."""return ""def __getattribute__(self, name): """ x.__getattribute__('name') <==> x.name """passdef __getformat__(self, typestr): """float.__getformat__(typestr) -> stringYou probably don't want to use this function. It exists mainly to beused in Python's test suite.typestr must be 'double' or 'float'. This function returns whichever of'unknown', 'IEEE, big-endian' or 'IEEE, little-endian' best describes theformat of floating point numbers used by the C type named by typestr."""return ""def __getnewargs__(self, *args, **kwargs): # real signature unknownpassdef __ge__(self, y): """ x.__ge__(y) <==> x>=y """passdef __gt__(self, y): """ x.__gt__(y) <==> x>y """passdef __hash__(self): """ x.__hash__() <==> hash(x) """passdef __init__(self, x): passdef __int__(self): """ x.__int__() <==> int(x) """passdef __le__(self, y): """ x.__le__(y) <==> x<=y """passdef __long__(self): """ x.__long__() <==> long(x) """passdef __lt__(self, y): """ x.__lt__(y) <==> x<y """passdef __mod__(self, y): """ x.__mod__(y) <==> x%y """passdef __mul__(self, y): """ x.__mul__(y) <==> x*y """passdef __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 """passdef __ne__(self, y): """ x.__ne__(y) <==> x!=y """passdef __nonzero__(self): """ x.__nonzero__() <==> x != 0 """passdef __pos__(self): """ x.__pos__() <==> +x """passdef __pow__(self, y, z=None): """ x.__pow__(y[, z]) <==> pow(x, y[, z]) """passdef __radd__(self, y): """ x.__radd__(y) <==> y+x """passdef __rdivmod__(self, y): """ x.__rdivmod__(y) <==> divmod(y, x) """passdef __rdiv__(self, y): """ x.__rdiv__(y) <==> y/x """passdef __repr__(self): """ x.__repr__() <==> repr(x) """passdef __rfloordiv__(self, y): """ x.__rfloordiv__(y) <==> y//x """passdef __rmod__(self, y): """ x.__rmod__(y) <==> y%x """passdef __rmul__(self, y): """ x.__rmul__(y) <==> y*x """passdef __rpow__(self, x, z=None): """ y.__rpow__(x[, z]) <==> pow(x, y[, z]) """passdef __rsub__(self, y): """ x.__rsub__(y) <==> y-x """passdef __rtruediv__(self, y): """ x.__rtruediv__(y) <==> y/x """passdef __setformat__(self, typestr, fmt): """float.__setformat__(typestr, fmt) -> NoneYou probably don't want to use this function. It exists mainly to beused in Python's test suite.typestr must be 'double' or 'float'. fmt must be one of 'unknown','IEEE, big-endian' or 'IEEE, little-endian', and in addition can only beone of the latter two if it appears to match the underlying C reality.Override the automatic determination of C-level floating point type.This affects how floats are converted to and from binary strings."""passdef __str__(self): """ x.__str__() <==> str(x) """passdef __sub__(self, y): """ x.__sub__(y) <==> x-y """passdef __truediv__(self, y): """ x.__truediv__(y) <==> x/y """passdef __trunc__(self, *args, **kwargs): # real signature unknown""" Return the Integral closest to x between 0 and x. """passimag = property(lambda self: object(), lambda self, v: None, lambda self: None) # default"""the imaginary part of a complex number"""real = property(lambda self: object(), lambda self, v: None, lambda self: None) # default"""the real part of a complex number"""

四、字符串

如：'wupeiqi'、'alex'

每個字符串都具備如下功能：

class str(basestring):"""str(object='') -> stringReturn a nice string representation of the object.If the argument is a string, the return value is the same object."""def capitalize(self): """ 首字母變大寫 """"""S.capitalize() -> stringReturn a copy of the string S with only its first charactercapitalized."""return ""def center(self, width, fillchar=None): """ 內容居中，width：總長度；fillchar：空白處填充內容，默認無 """"""S.center(width[, fillchar]) -> stringReturn S centered in a string of length width. Padding isdone using the specified fill character (default is a space)"""return ""def count(self, sub, start=None, end=None): """ 子序列個數 """"""S.count(sub[, start[, end]]) -> intReturn the number of non-overlapping occurrences of substring sub instring S[start:end]. Optional arguments start and end are interpretedas in slice notation."""return 0def decode(self, encoding=None, errors=None): """ 解碼 """"""S.decode([encoding[,errors]]) -> objectDecodes S using the codec registered for encoding. encoding defaultsto the default encoding. errors may be given to set a different errorhandling scheme. Default is 'strict' meaning that encoding errors raisea UnicodeDecodeError. Other possible values are 'ignore' and 'replace'as well as any other name registered with codecs.register_error that isable to handle UnicodeDecodeErrors."""return object()def encode(self, encoding=None, errors=None): """ 編碼，針對unicode """"""S.encode([encoding[,errors]]) -> objectEncodes S using the codec registered for encoding. encoding defaultsto the default encoding. errors may be given to set a different errorhandling scheme. Default is 'strict' meaning that encoding errors raisea UnicodeEncodeError. Other possible values are 'ignore', 'replace' and'xmlcharrefreplace' as well as any other name registered withcodecs.register_error that is able to handle UnicodeEncodeErrors."""return object()def endswith(self, suffix, start=None, end=None): """ 是否以 xxx 結束 """"""S.endswith(suffix[, start[, end]]) -> boolReturn 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 Falsedef expandtabs(self, tabsize=None): """ 將tab轉換成空格，默認一個tab轉換成8個空格 """"""S.expandtabs([tabsize]) -> stringReturn 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): """ 尋找子序列位置，如果沒找到，返回 -1 """"""S.find(sub [,start [,end]]) -> intReturn the lowest index in S where substring sub is found,such that sub is contained within S[start:end]. Optionalarguments start and end are interpreted as in slice notation.Return -1 on failure."""return 0def format(*args, **kwargs): # known special case of str.format""" 字符串格式化，動態參數，將函數式編程時細說 """"""S.format(*args, **kwargs) -> stringReturn a formatted version of S, using substitutions from args and kwargs.The substitutions are identified by braces ('{' and '}')."""passdef index(self, sub, start=None, end=None): """ 子序列位置，如果沒找到，報錯 """S.index(sub [,start [,end]]) -> intLike S.find() but raise ValueError when the substring is not found."""return 0def isalnum(self): """ 是否是字母和數字 """"""S.isalnum() -> boolReturn True if all characters in S are alphanumericand there is at least one character in S, False otherwise."""return Falsedef isalpha(self): """ 是否是字母 """"""S.isalpha() -> boolReturn True if all characters in S are alphabeticand there is at least one character in S, False otherwise."""return Falsedef isdigit(self): """ 是否是數字 """"""S.isdigit() -> boolReturn True if all characters in S are digitsand there is at least one character in S, False otherwise."""return Falsedef islower(self): """ 是否小寫 """"""S.islower() -> boolReturn True if all cased characters in S are lowercase and there isat least one cased character in S, False otherwise."""return Falsedef isspace(self): """S.isspace() -> boolReturn True if all characters in S are whitespaceand there is at least one character in S, False otherwise."""return Falsedef istitle(self): """S.istitle() -> boolReturn True if S is a titlecased string and there is at least onecharacter in S, i.e. uppercase characters may only follow uncasedcharacters and lowercase characters only cased ones. Return Falseotherwise."""return Falsedef isupper(self): """S.isupper() -> boolReturn True if all cased characters in S are uppercase and there isat least one cased character in S, False otherwise."""return Falsedef join(self, iterable): """ 連接 """"""S.join(iterable) -> stringReturn a string which is the concatenation of the strings in theiterable. The separator between elements is S."""return ""def ljust(self, width, fillchar=None): """ 內容左對齊，右側填充 """"""S.ljust(width[, fillchar]) -> stringReturn S left-justified in a string of length width. Padding isdone using the specified fill character (default is a space)."""return ""def lower(self): """ 變小寫 """"""S.lower() -> stringReturn a copy of the string S converted to lowercase."""return ""def lstrip(self, chars=None): """ 移除左側空白 """"""S.lstrip([chars]) -> string or unicodeReturn 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 notfound, return S and two empty strings."""passdef replace(self, old, new, count=None): """ 替換 """"""S.replace(old, new[, count]) -> stringReturn a copy of string S with all occurrences of substringold replaced by new. If the optional argument count isgiven, only the first count occurrences are replaced."""return ""def rfind(self, sub, start=None, end=None): """S.rfind(sub [,start [,end]]) -> intReturn the highest index in S where substring sub is found,such that sub is contained within S[start:end]. Optionalarguments start and end are interpreted as in slice notation.Return -1 on failure."""return 0def rindex(self, sub, start=None, end=None): """S.rindex(sub [,start [,end]]) -> intLike S.rfind() but raise ValueError when the substring is not found."""return 0def rjust(self, width, fillchar=None): """S.rjust(width[, fillchar]) -> stringReturn S right-justified in a string of length width. Padding isdone 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 returnthe part before it, the separator itself, and the part after it. If theseparator is not found, return two empty strings and S."""passdef rsplit(self, sep=None, maxsplit=None): """S.rsplit([sep [,maxsplit]]) -> list of stringsReturn a list of the words in the string S, using sep as thedelimiter string, starting at the end of the string and workingto the front. If maxsplit is given, at most maxsplit splits aredone. If sep is not specified or is None, any whitespace stringis a separator."""return []def rstrip(self, chars=None): """S.rstrip([chars]) -> string or unicodeReturn 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最多分割幾次 """"""S.split([sep [,maxsplit]]) -> list of stringsReturn a list of the words in the string S, using sep as thedelimiter string. If maxsplit is given, at most maxsplitsplits are done. If sep is not specified or is None, anywhitespace string is a separator and empty strings are removedfrom the result."""return []def splitlines(self, keepends=False): """ 根據換行分割 """"""S.splitlines(keepends=False) -> list of stringsReturn a list of the lines in S, breaking at line boundaries.Line breaks are not included in the resulting list unless keependsis given and true."""return []def startswith(self, prefix, start=None, end=None): """ 是否起始 """"""S.startswith(prefix[, start[, end]]) -> boolReturn 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 Falsedef strip(self, chars=None): """ 移除兩段空白 """"""S.strip([chars]) -> string or unicodeReturn a copy of the string S with leading and trailingwhitespace 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): """ 大寫變小寫，小寫變大寫 """"""S.swapcase() -> stringReturn a copy of the string S with uppercase charactersconverted to lowercase and vice versa."""return ""def title(self): """S.title() -> stringReturn a titlecased version of S, i.e. words start with uppercasecharacters, all remaining cased characters have lowercase."""return ""def translate(self, table, deletechars=None): """轉換，需要先做一個對應表，最后一個表示刪除字符集合intab = "aeiou"outtab = "12345"trantab = maketrans(intab, outtab)str = "this is string example....wow!!!"print str.translate(trantab, 'xm')""""""S.translate(table [,deletechars]) -> stringReturn a copy of the string S, where all characters occurringin the optional argument deletechars are removed, and theremaining characters have been mapped through the giventranslation table, which must be a string of length 256 or None.If the table argument is None, no translation is applied andthe operation simply removes the characters in deletechars."""return ""def upper(self): """S.upper() -> stringReturn a copy of the string S converted to uppercase."""return ""def zfill(self, width): """方法返回指定長度的字符串，原字符串右對齊，前面填充0。""""""S.zfill(width) -> stringPad a numeric string S with zeros on the left, to fill a fieldof the specified width. The string S is never truncated."""return ""def _formatter_field_name_split(self, *args, **kwargs): # real signature unknownpassdef _formatter_parser(self, *args, **kwargs): # real signature unknownpassdef __add__(self, y): """ x.__add__(y) <==> x+y """passdef __contains__(self, y): """ x.__contains__(y) <==> y in x """passdef __eq__(self, y): """ x.__eq__(y) <==> x==y """passdef __format__(self, format_spec): """S.__format__(format_spec) -> stringReturn a formatted version of S as described by format_spec."""return ""def __getattribute__(self, name): """ x.__getattribute__('name') <==> x.name """passdef __getitem__(self, y): """ x.__getitem__(y) <==> x[y] """passdef __getnewargs__(self, *args, **kwargs): # real signature unknownpassdef __getslice__(self, i, j): """x.__getslice__(i, j) <==> x[i:j]Use of negative indices is not supported."""passdef __ge__(self, y): """ x.__ge__(y) <==> x>=y """passdef __gt__(self, y): """ x.__gt__(y) <==> x>y """passdef __hash__(self): """ x.__hash__() <==> hash(x) """passdef __init__(self, string=''): # known special case of str.__init__"""str(object='') -> stringReturn a nice string representation of the object.If the argument is a string, the return value is the same object.# (copied from class doc)"""passdef __len__(self): """ x.__len__() <==> len(x) """passdef __le__(self, y): """ x.__le__(y) <==> x<=y """passdef __lt__(self, y): """ x.__lt__(y) <==> x<y """passdef __mod__(self, y): """ x.__mod__(y) <==> x%y """passdef __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 """passdef __ne__(self, y): """ x.__ne__(y) <==> x!=y """passdef __repr__(self): """ x.__repr__() <==> repr(x) """passdef __rmod__(self, y): """ x.__rmod__(y) <==> y%x """passdef __rmul__(self, n): """ x.__rmul__(n) <==> n*x """passdef __sizeof__(self): """ S.__sizeof__() -> size of S in memory, in bytes """passdef __str__(self): """ x.__str__() <==> str(x) """passstr

注：編碼；字符串的乘法；字符串和格式化

五、列表

如：[11,22,33]、['wupeiqi', 'alex']

每個列表都具備如下功能：

class list(object):"""list() -> new empty listlist(iterable) -> new list initialized from iterable's items"""def append(self, p_object): # real signature unknown; restored from __doc__""" L.append(object) -- append object to end """passdef count(self, value): # real signature unknown; restored from __doc__""" L.count(value) -> integer -- return number of occurrences of value """return 0def extend(self, iterable): # real signature unknown; restored from __doc__""" L.extend(iterable) -- extend list by appending elements from the iterable """passdef index(self, value, start=None, stop=None): # real signature unknown; restored from __doc__"""L.index(value, [start, [stop]]) -> integer -- return first index of value.Raises ValueError if the value is not present."""return 0def insert(self, index, p_object): # real signature unknown; restored from __doc__""" L.insert(index, object) -- insert object before index """passdef pop(self, index=None): # real signature unknown; restored from __doc__"""L.pop([index]) -> item -- remove and return item at index (default last).Raises IndexError if list is empty or index is out of range."""passdef remove(self, value): # real signature unknown; restored from __doc__"""L.remove(value) -- remove first occurrence of value.Raises ValueError if the value is not present."""passdef reverse(self): # real signature unknown; restored from __doc__""" L.reverse() -- reverse *IN PLACE* """passdef sort(self, cmp=None, key=None, reverse=False): # real signature unknown; restored from __doc__"""L.sort(cmp=None, key=None, reverse=False) -- stable sort *IN PLACE*;cmp(x, y) -> -1, 0, 1"""passdef __add__(self, y): # real signature unknown; restored from __doc__""" x.__add__(y) <==> x+y """passdef __contains__(self, y): # real signature unknown; restored from __doc__""" x.__contains__(y) <==> y in x """passdef __delitem__(self, y): # real signature unknown; restored from __doc__""" x.__delitem__(y) <==> del x[y] """passdef __delslice__(self, i, j): # real signature unknown; restored from __doc__"""x.__delslice__(i, j) <==> del x[i:j]Use of negative indices is not supported."""passdef __eq__(self, y): # real signature unknown; restored from __doc__""" x.__eq__(y) <==> x==y """passdef __getattribute__(self, name): # real signature unknown; restored from __doc__""" x.__getattribute__('name') <==> x.name """passdef __getitem__(self, y): # real signature unknown; restored from __doc__""" x.__getitem__(y) <==> x[y] """passdef __getslice__(self, i, j): # real signature unknown; restored from __doc__"""x.__getslice__(i, j) <==> x[i:j]Use of negative indices is not supported."""passdef __ge__(self, y): # real signature unknown; restored from __doc__""" x.__ge__(y) <==> x>=y """passdef __gt__(self, y): # real signature unknown; restored from __doc__""" x.__gt__(y) <==> x>y """passdef __iadd__(self, y): # real signature unknown; restored from __doc__""" x.__iadd__(y) <==> x+=y """passdef __imul__(self, y): # real signature unknown; restored from __doc__""" x.__imul__(y) <==> x*=y """passdef __init__(self, seq=()): # known special case of list.__init__"""list() -> new empty listlist(iterable) -> new list initialized from iterable's items# (copied from class doc)"""passdef __iter__(self): # real signature unknown; restored from __doc__""" x.__iter__() <==> iter(x) """passdef __len__(self): # real signature unknown; restored from __doc__""" x.__len__() <==> len(x) """passdef __le__(self, y): # real signature unknown; restored from __doc__""" x.__le__(y) <==> x<=y """passdef __lt__(self, y): # real signature unknown; restored from __doc__""" x.__lt__(y) <==> x<y """passdef __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 """passdef __ne__(self, y): # real signature unknown; restored from __doc__""" x.__ne__(y) <==> x!=y """passdef __repr__(self): # real signature unknown; restored from __doc__""" x.__repr__() <==> repr(x) """passdef __reversed__(self): # real signature unknown; restored from __doc__""" L.__reversed__() -- return a reverse iterator over the list """passdef __rmul__(self, n): # real signature unknown; restored from __doc__""" x.__rmul__(n) <==> n*x """passdef __setitem__(self, i, y): # real signature unknown; restored from __doc__""" x.__setitem__(i, y) <==> x[i]=y """passdef __setslice__(self, i, j, y): # real signature unknown; restored from __doc__"""x.__setslice__(i, j, y) <==> x[i:j]=yUse of negative indices is not supported."""passdef __sizeof__(self): # real signature unknown; restored from __doc__""" L.__sizeof__() -- size of L in memory, in bytes """pass__hash__ = None

注：排序；

六、元組

如：(11,22,33)、('wupeiqi', 'alex')

每個元組都具備如下功能：

class tuple(object):"""tuple() -> empty tupletuple(iterable) -> tuple initialized from iterable's itemsIf 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 0def 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 0def __add__(self, y): # real signature unknown; restored from __doc__""" x.__add__(y) <==> x+y """passdef __contains__(self, y): # real signature unknown; restored from __doc__""" x.__contains__(y) <==> y in x """passdef __eq__(self, y): # real signature unknown; restored from __doc__""" x.__eq__(y) <==> x==y """passdef __getattribute__(self, name): # real signature unknown; restored from __doc__""" x.__getattribute__('name') <==> x.name """passdef __getitem__(self, y): # real signature unknown; restored from __doc__""" x.__getitem__(y) <==> x[y] """passdef __getnewargs__(self, *args, **kwargs): # real signature unknownpassdef __getslice__(self, i, j): # real signature unknown; restored from __doc__"""x.__getslice__(i, j) <==> x[i:j]Use of negative indices is not supported."""passdef __ge__(self, y): # real signature unknown; restored from __doc__""" x.__ge__(y) <==> x>=y """passdef __gt__(self, y): # real signature unknown; restored from __doc__""" x.__gt__(y) <==> x>y """passdef __hash__(self): # real signature unknown; restored from __doc__""" x.__hash__() <==> hash(x) """passdef __init__(self, seq=()): # known special case of tuple.__init__"""tuple() -> empty tupletuple(iterable) -> tuple initialized from iterable's itemsIf the argument is a tuple, the return value is the same object.# (copied from class doc)"""passdef __iter__(self): # real signature unknown; restored from __doc__""" x.__iter__() <==> iter(x) """passdef __len__(self): # real signature unknown; restored from __doc__""" x.__len__() <==> len(x) """passdef __le__(self, y): # real signature unknown; restored from __doc__""" x.__le__(y) <==> x<=y """passdef __lt__(self, y): # real signature unknown; restored from __doc__""" x.__lt__(y) <==> x<y """passdef __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 """passdef __ne__(self, y): # real signature unknown; restored from __doc__""" x.__ne__(y) <==> x!=y """passdef __repr__(self): # real signature unknown; restored from __doc__""" x.__repr__() <==> repr(x) """passdef __rmul__(self, n): # real signature unknown; restored from __doc__""" x.__rmul__(n) <==> n*x """passdef __sizeof__(self): # real signature unknown; restored from __doc__""" T.__sizeof__() -- size of T in memory, in bytes """pass

七、字典

如：{'name': 'wupeiqi', 'age': 18} 、{'host': '2.2.2.2', 'port': 80]}

ps：循環時，默認循環key

每個字典都具備如下功能：

class dict(object):"""dict() -> new empty dictionarydict(mapping) -> new dictionary initialized from a mapping object's(key, value) pairsdict(iterable) -> new dictionary initialized as if via:d = {}for k, v in iterable:d[k] = vdict(**kwargs) -> new dictionary initialized with the name=value pairsin the keyword argument list. For example: dict(one=1, two=2)"""def clear(self): # real signature unknown; restored from __doc__""" 清除內容 """""" D.clear() -> None. Remove all items from D. """passdef copy(self): # real signature unknown; restored from __doc__""" 淺拷貝 """""" D.copy() -> a shallow copy of D """pass@staticmethod # known casedef 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."""passdef get(self, k, d=None): # real signature unknown; restored from __doc__""" 根據key獲取值，d是默認值 """""" D.get(k[,d]) -> D[k] if k in D, else d. d defaults to None. """passdef 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 Falsedef items(self): # real signature unknown; restored from __doc__""" 所有項的列表形式 """""" D.items() -> list of D's (key, value) pairs, as 2-tuples """return []def iteritems(self): # real signature unknown; restored from __doc__""" 項可迭代 """""" D.iteritems() -> an iterator over the (key, value) items of D """passdef iterkeys(self): # real signature unknown; restored from __doc__""" key可迭代 """""" D.iterkeys() -> an iterator over the keys of D """passdef itervalues(self): # real signature unknown; restored from __doc__""" value可迭代 """""" D.itervalues() -> an iterator over the values of D """passdef 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__""" 獲取并在字典中移除 """"""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"""passdef popitem(self): # real signature unknown; restored from __doc__""" 獲取并在字典中移除 """"""D.popitem() -> (k, v), remove and return some (key, value) pair as a2-tuple; but raise KeyError if D is empty."""passdef setdefault(self, k, d=None): # real signature unknown; restored from __doc__""" 如果key不存在，則創建，如果存在，則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 """passdef 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] = vIn either case, this is followed by: for k in F: D[k] = F[k]"""passdef 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__""" 所有項，只是將內容保存至view對象中 """""" D.viewitems() -> a set-like object providing a view on D's items """passdef viewkeys(self): # real signature unknown; restored from __doc__""" D.viewkeys() -> a set-like object providing a view on D's keys """passdef viewvalues(self): # real signature unknown; restored from __doc__""" D.viewvalues() -> an object providing a view on D's values """passdef __cmp__(self, y): # real signature unknown; restored from __doc__""" x.__cmp__(y) <==> cmp(x,y) """passdef __contains__(self, k): # real signature unknown; restored from __doc__""" D.__contains__(k) -> True if D has a key k, else False """return Falsedef __delitem__(self, y): # real signature unknown; restored from __doc__""" x.__delitem__(y) <==> del x[y] """passdef __eq__(self, y): # real signature unknown; restored from __doc__""" x.__eq__(y) <==> x==y """passdef __getattribute__(self, name): # real signature unknown; restored from __doc__""" x.__getattribute__('name') <==> x.name """passdef __getitem__(self, y): # real signature unknown; restored from __doc__""" x.__getitem__(y) <==> x[y] """passdef __ge__(self, y): # real signature unknown; restored from __doc__""" x.__ge__(y) <==> x>=y """passdef __gt__(self, y): # real signature unknown; restored from __doc__""" x.__gt__(y) <==> x>y """passdef __init__(self, seq=None, **kwargs): # known special case of dict.__init__"""dict() -> new empty dictionarydict(mapping) -> new dictionary initialized from a mapping object's(key, value) pairsdict(iterable) -> new dictionary initialized as if via:d = {}for k, v in iterable:d[k] = vdict(**kwargs) -> new dictionary initialized with the name=value pairsin the keyword argument list. For example: dict(one=1, two=2)# (copied from class doc)"""passdef __iter__(self): # real signature unknown; restored from __doc__""" x.__iter__() <==> iter(x) """passdef __len__(self): # real signature unknown; restored from __doc__""" x.__len__() <==> len(x) """passdef __le__(self, y): # real signature unknown; restored from __doc__""" x.__le__(y) <==> x<=y """passdef __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 """passdef __ne__(self, y): # real signature unknown; restored from __doc__""" x.__ne__(y) <==> x!=y """passdef __repr__(self): # real signature unknown; restored from __doc__""" x.__repr__() <==> repr(x) """passdef __setitem__(self, i, y): # real signature unknown; restored from __doc__""" x.__setitem__(i, y) <==> x[i]=y """passdef __sizeof__(self): # real signature unknown; restored from __doc__""" D.__sizeof__() -> size of D in memory, in bytes """pass__hash__ = None

1 2 3

練習：元素分類 有如下值集合 [11,22,33,44,55,66,77,88,99,90...]，將所有大于?66?的值保存至字典的第一個key中，將小于?66?的值保存至第二個key的值中。 即： {'k1': 大于66?,?'k2': 小于66}

?八、set集合

set是一個無序且不重復的元素集合

class set(object):"""set() -> new empty set objectset(iterable) -> new set objectBuild an unordered collection of unique elements."""def add(self, *args, **kwargs): # real signature unknown""" 添加 """"""Add an element to a set.This has no effect if the element is already present."""passdef clear(self, *args, **kwargs): # real signature unknown""" Remove all elements from this set. """passdef copy(self, *args, **kwargs): # real signature unknown""" Return a shallow copy of a set. """passdef difference(self, *args, **kwargs): # real signature unknown"""Return the difference of two or more sets as a new set.(i.e. all elements that are in this set but not the others.)"""passdef difference_update(self, *args, **kwargs): # real signature unknown""" 刪除當前set中的所有包含在 new set 里的元素 """""" Remove all elements of another set from this set. """passdef discard(self, *args, **kwargs): # real signature unknown""" 移除元素 """"""Remove an element from a set if it is a member.If the element is not a member, do nothing."""passdef intersection(self, *args, **kwargs): # real signature unknown""" 取交集，新創建一個set """"""Return the intersection of two or more sets as a new set.(i.e. elements that are common to all of the sets.)"""passdef intersection_update(self, *args, **kwargs): # real signature unknown""" 取交集，修改原來set """""" Update a set with the intersection of itself and another. """passdef isdisjoint(self, *args, **kwargs): # real signature unknown""" 如果沒有交集，返回true """""" Return True if two sets have a null intersection. """passdef issubset(self, *args, **kwargs): # real signature unknown""" 是否是子集 """""" Report whether another set contains this set. """passdef issuperset(self, *args, **kwargs): # real signature unknown""" 是否是父集 """""" Report whether this set contains another set. """passdef pop(self, *args, **kwargs): # real signature unknown""" 移除 """"""Remove and return an arbitrary set element.Raises KeyError if the set is empty."""passdef remove(self, *args, **kwargs): # real signature unknown""" 移除 """"""Remove an element from a set; it must be a member.If the element is not a member, raise a KeyError."""passdef symmetric_difference(self, *args, **kwargs): # real signature unknown""" 差集，創建新對象""""""Return the symmetric difference of two sets as a new set.(i.e. all elements that are in exactly one of the sets.)"""passdef symmetric_difference_update(self, *args, **kwargs): # real signature unknown""" 差集，改變原來 """""" Update a set with the symmetric difference of itself and another. """passdef union(self, *args, **kwargs): # real signature unknown""" 并集 """"""Return the union of sets as a new set.(i.e. all elements that are in either set.)"""passdef update(self, *args, **kwargs): # real signature unknown""" 更新 """""" Update a set with the union of itself and others. """passdef __and__(self, y): # real signature unknown; restored from __doc__""" x.__and__(y) <==> x&y """passdef __cmp__(self, y): # real signature unknown; restored from __doc__""" x.__cmp__(y) <==> cmp(x,y) """passdef __contains__(self, y): # real signature unknown; restored from __doc__""" x.__contains__(y) <==> y in x. """passdef __eq__(self, y): # real signature unknown; restored from __doc__""" x.__eq__(y) <==> x==y """passdef __getattribute__(self, name): # real signature unknown; restored from __doc__""" x.__getattribute__('name') <==> x.name """passdef __ge__(self, y): # real signature unknown; restored from __doc__""" x.__ge__(y) <==> x>=y """passdef __gt__(self, y): # real signature unknown; restored from __doc__""" x.__gt__(y) <==> x>y """passdef __iand__(self, y): # real signature unknown; restored from __doc__""" x.__iand__(y) <==> x&=y """passdef __init__(self, seq=()): # known special case of set.__init__"""set() -> new empty set objectset(iterable) -> new set objectBuild an unordered collection of unique elements.# (copied from class doc)"""passdef __ior__(self, y): # real signature unknown; restored from __doc__""" x.__ior__(y) <==> x|=y """passdef __isub__(self, y): # real signature unknown; restored from __doc__""" x.__isub__(y) <==> x-=y """passdef __iter__(self): # real signature unknown; restored from __doc__""" x.__iter__() <==> iter(x) """passdef __ixor__(self, y): # real signature unknown; restored from __doc__""" x.__ixor__(y) <==> x^=y """passdef __len__(self): # real signature unknown; restored from __doc__""" x.__len__() <==> len(x) """passdef __le__(self, y): # real signature unknown; restored from __doc__""" x.__le__(y) <==> x<=y """passdef __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 """passdef __ne__(self, y): # real signature unknown; restored from __doc__""" x.__ne__(y) <==> x!=y """passdef __or__(self, y): # real signature unknown; restored from __doc__""" x.__or__(y) <==> x|y """passdef __rand__(self, y): # real signature unknown; restored from __doc__""" x.__rand__(y) <==> y&x """passdef __reduce__(self, *args, **kwargs): # real signature unknown""" Return state information for pickling. """passdef __repr__(self): # real signature unknown; restored from __doc__""" x.__repr__() <==> repr(x) """passdef __ror__(self, y): # real signature unknown; restored from __doc__""" x.__ror__(y) <==> y|x """passdef __rsub__(self, y): # real signature unknown; restored from __doc__""" x.__rsub__(y) <==> y-x """passdef __rxor__(self, y): # real signature unknown; restored from __doc__""" x.__rxor__(y) <==> y^x """passdef __sizeof__(self): # real signature unknown; restored from __doc__""" S.__sizeof__() -> size of S in memory, in bytes """passdef __sub__(self, y): # real signature unknown; restored from __doc__""" x.__sub__(y) <==> x-y """passdef __xor__(self, y): # real signature unknown; restored from __doc__""" x.__xor__(y) <==> x^y """pass__hash__ = None

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

練習：尋找差異 # 數據庫中原有 old_dict?=?{ ????"#1":{?'hostname':c1,?'cpu_count':?2,?'mem_capicity':?80?}, ????"#2":{?'hostname':c1,?'cpu_count':?2,?'mem_capicity':?80?} ????"#3":{?'hostname':c1,?'cpu_count':?2,?'mem_capicity':?80?} } # cmdb 新匯報的數據 new_dict?=?{ ????"#1":{?'hostname':c1,?'cpu_count':?2,?'mem_capicity':?800?}, ????"#3":{?'hostname':c1,?'cpu_count':?2,?'mem_capicity':?80?} ????"#4":{?'hostname':c2,?'cpu_count':?2,?'mem_capicity':?80?} } 需要刪除：？ 需要新建：？ 需要更新：？ 注意：無需考慮內部元素是否改變，只要原來存在，新匯報也存在，就是需要更新

old_set = set(old_dict.keys()) update_list = list(old_set.intersection(new_dict.keys()))new_list = [] del_list = []for i in new_dict.keys():if i not in update_list:new_list.append(i)for i in old_dict.keys():if i not in update_list:del_list.append(i)print update_list,new_list,del_list ?

九、collection系列

1、計數器（counter）

Counter是對字典類型的補充，用于追蹤值的出現次數。

ps：具備字典的所有功能 + 自己的功能

1 2 3

c?=?Counter('abcdeabcdabcaba') print?c 輸出：Counter({'a':?5,?'b':?4,?'c':?3,?'d':?2,?'e':?1})

######################################################################## ### Counter ########################################################################class Counter(dict):'''Dict subclass for counting hashable items. Sometimes called a bagor multiset. Elements are stored as dictionary keys and their countsare stored as dictionary values.>>> c = Counter('abcdeabcdabcaba') # count elements from a string>>> c.most_common(3) # three most common elements[('a', 5), ('b', 4), ('c', 3)]>>> sorted(c) # list all unique elements['a', 'b', 'c', 'd', 'e']>>> ''.join(sorted(c.elements())) # list elements with repetitions'aaaaabbbbcccdde'>>> sum(c.values()) # total of all counts>>> c['a'] # count of letter 'a'>>> for elem in 'shazam': # update counts from an iterable... c[elem] += 1 # by adding 1 to each element's count>>> c['a'] # now there are seven 'a'>>> del c['b'] # remove all 'b'>>> c['b'] # now there are zero 'b'>>> d = Counter('simsalabim') # make another counter>>> c.update(d) # add in the second counter>>> c['a'] # now there are nine 'a'>>> c.clear() # empty the counter>>> cCounter()Note: If a count is set to zero or reduced to zero, it will remainin the counter until the entry is deleted or the counter is cleared:>>> c = Counter('aaabbc')>>> c['b'] -= 2 # reduce the count of 'b' by two>>> c.most_common() # 'b' is still in, but its count is zero[('a', 3), ('c', 1), ('b', 0)]'''# References:# http://en.wikipedia.org/wiki/Multiset# http://www.gnu.org/software/smalltalk/manual-base/html_node/Bag.html# http://www.demo2s.com/Tutorial/Cpp/0380__set-multiset/Catalog0380__set-multiset.htm# http://code.activestate.com/recipes/259174/# Knuth, TAOCP Vol. II section 4.6.3def __init__(self, iterable=None, **kwds):'''Create a new, empty Counter object. And if given, count elementsfrom an input iterable. Or, initialize the count from another mappingof elements to their counts.>>> c = Counter() # a new, empty counter>>> c = Counter('gallahad') # a new counter from an iterable>>> c = Counter({'a': 4, 'b': 2}) # a new counter from a mapping>>> c = Counter(a=4, b=2) # a new counter from keyword args'''super(Counter, self).__init__()self.update(iterable, **kwds)def __missing__(self, key):""" 對于不存在的元素，返回計數器為0 """'The count of elements not in the Counter is zero.'# Needed so that self[missing_item] does not raise KeyErrorreturn 0def most_common(self, n=None):""" 數量從大到寫排列，獲取前N個元素 """'''List the n most common elements and their counts from the mostcommon to the least. If n is None, then list all element counts.>>> Counter('abcdeabcdabcaba').most_common(3)[('a', 5), ('b', 4), ('c', 3)]'''# Emulate Bag.sortedByCount from Smalltalkif n is None:return sorted(self.iteritems(), key=_itemgetter(1), reverse=True)return _heapq.nlargest(n, self.iteritems(), key=_itemgetter(1))def elements(self):""" 計數器中的所有元素，注：此處非所有元素集合，而是包含所有元素集合的迭代器 """'''Iterator over elements repeating each as many times as its count.>>> c = Counter('ABCABC')>>> sorted(c.elements())['A', 'A', 'B', 'B', 'C', 'C']# Knuth's example for prime factors of 1836: 2**2 * 3**3 * 17**1>>> prime_factors = Counter({2: 2, 3: 3, 17: 1})>>> product = 1>>> for factor in prime_factors.elements(): # loop over factors... product *= factor # and multiply them>>> productNote, if an element's count has been set to zero or is a negativenumber, elements() will ignore it.'''# Emulate Bag.do from Smalltalk and Multiset.begin from C++.return _chain.from_iterable(_starmap(_repeat, self.iteritems()))# Override dict methods where necessary@classmethoddef fromkeys(cls, iterable, v=None):# There is no equivalent method for counters because setting v=1# means that no element can have a count greater than one.raise NotImplementedError('Counter.fromkeys() is undefined. Use Counter(iterable) instead.')def update(self, iterable=None, **kwds):""" 更新計數器，其實就是增加；如果原來沒有，則新建，如果有則加一 """'''Like dict.update() but add counts instead of replacing them.Source can be an iterable, a dictionary, or another Counter instance.>>> c = Counter('which')>>> c.update('witch') # add elements from another iterable>>> d = Counter('watch')>>> c.update(d) # add elements from another counter>>> c['h'] # four 'h' in which, witch, and watch'''# The regular dict.update() operation makes no sense here because the# replace behavior results in the some of original untouched counts# being mixed-in with all of the other counts for a mismash that# doesn't have a straight-forward interpretation in most counting# contexts. Instead, we implement straight-addition. Both the inputs# and outputs are allowed to contain zero and negative counts.if iterable is not None:if isinstance(iterable, Mapping):if self:self_get = self.getfor elem, count in iterable.iteritems():self[elem] = self_get(elem, 0) + countelse:super(Counter, self).update(iterable) # fast path when counter is emptyelse:self_get = self.getfor elem in iterable:self[elem] = self_get(elem, 0) + 1if kwds:self.update(kwds)def subtract(self, iterable=None, **kwds):""" 相減，原來的計數器中的每一個元素的數量減去后添加的元素的數量 """'''Like dict.update() but subtracts counts instead of replacing them.Counts can be reduced below zero. Both the inputs and outputs areallowed to contain zero and negative counts.Source can be an iterable, a dictionary, or another Counter instance.>>> c = Counter('which')>>> c.subtract('witch') # subtract elements from another iterable>>> c.subtract(Counter('watch')) # subtract elements from another counter>>> c['h'] # 2 in which, minus 1 in witch, minus 1 in watch>>> c['w'] # 1 in which, minus 1 in witch, minus 1 in watch-1'''if iterable is not None:self_get = self.getif isinstance(iterable, Mapping):for elem, count in iterable.items():self[elem] = self_get(elem, 0) - countelse:for elem in iterable:self[elem] = self_get(elem, 0) - 1if kwds:self.subtract(kwds)def copy(self):""" 拷貝 """'Return a shallow copy.'return self.__class__(self)def __reduce__(self):""" 返回一個元組（類型，元組） """return self.__class__, (dict(self),)def __delitem__(self, elem):""" 刪除元素 """'Like dict.__delitem__() but does not raise KeyError for missing values.'if elem in self:super(Counter, self).__delitem__(elem)def __repr__(self):if not self:return '%s()' % self.__class__.__name__items = ', '.join(map('%r: %r'.__mod__, self.most_common()))return '%s({%s})' % (self.__class__.__name__, items)# Multiset-style mathematical operations discussed in:# Knuth TAOCP Volume II section 4.6.3 exercise 19# and at http://en.wikipedia.org/wiki/Multiset## Outputs guaranteed to only include positive counts.## To strip negative and zero counts, add-in an empty counter:# c += Counter()def __add__(self, other):'''Add counts from two counters.>>> Counter('abbb') + Counter('bcc')Counter({'b': 4, 'c': 2, 'a': 1})'''if not isinstance(other, Counter):return NotImplementedresult = Counter()for elem, count in self.items():newcount = count + other[elem]if newcount > 0:result[elem] = newcountfor elem, count in other.items():if elem not in self and count > 0:result[elem] = countreturn resultdef __sub__(self, other):''' Subtract count, but keep only results with positive counts.>>> Counter('abbbc') - Counter('bccd')Counter({'b': 2, 'a': 1})'''if not isinstance(other, Counter):return NotImplementedresult = Counter()for elem, count in self.items():newcount = count - other[elem]if newcount > 0:result[elem] = newcountfor elem, count in other.items():if elem not in self and count < 0:result[elem] = 0 - countreturn resultdef __or__(self, other):'''Union is the maximum of value in either of the input counters.>>> Counter('abbb') | Counter('bcc')Counter({'b': 3, 'c': 2, 'a': 1})'''if not isinstance(other, Counter):return NotImplementedresult = Counter()for elem, count in self.items():other_count = other[elem]newcount = other_count if count < other_count else countif newcount > 0:result[elem] = newcountfor elem, count in other.items():if elem not in self and count > 0:result[elem] = countreturn resultdef __and__(self, other):''' Intersection is the minimum of corresponding counts.>>> Counter('abbb') & Counter('bcc')Counter({'b': 1})'''if not isinstance(other, Counter):return NotImplementedresult = Counter()for elem, count in self.items():other_count = other[elem]newcount = count if count < other_count else other_countif newcount > 0:result[elem] = newcountreturn result

2、有序字典(orderedDict )

orderdDict是對字典類型的補充，他記住了字典元素添加的順序

class OrderedDict(dict):'Dictionary that remembers insertion order'# An inherited dict maps keys to values.# The inherited dict provides __getitem__, __len__, __contains__, and get.# The remaining methods are order-aware.# Big-O running times for all methods are the same as regular dictionaries.# The internal self.__map dict maps keys to links in a doubly linked list.# The circular doubly linked list starts and ends with a sentinel element.# The sentinel element never gets deleted (this simplifies the algorithm).# Each link is stored as a list of length three: [PREV, NEXT, KEY].def __init__(self, *args, **kwds):'''Initialize an ordered dictionary. The signature is the same asregular dictionaries, but keyword arguments are not recommended becausetheir insertion order is arbitrary.'''if len(args) > 1:raise TypeError('expected at most 1 arguments, got %d' % len(args))try:self.__rootexcept AttributeError:self.__root = root = [] # sentinel noderoot[:] = [root, root, None]self.__map = {}self.__update(*args, **kwds)def __setitem__(self, key, value, dict_setitem=dict.__setitem__):'od.__setitem__(i, y) <==> od[i]=y'# Setting a new item creates a new link at the end of the linked list,# and the inherited dictionary is updated with the new key/value pair.if key not in self:root = self.__rootlast = root[0]last[1] = root[0] = self.__map[key] = [last, root, key]return dict_setitem(self, key, value)def __delitem__(self, key, dict_delitem=dict.__delitem__):'od.__delitem__(y) <==> del od[y]'# Deleting an existing item uses self.__map to find the link which gets# removed by updating the links in the predecessor and successor nodes.dict_delitem(self, key)link_prev, link_next, _ = self.__map.pop(key)link_prev[1] = link_next # update link_prev[NEXT]link_next[0] = link_prev # update link_next[PREV]def __iter__(self):'od.__iter__() <==> iter(od)'# Traverse the linked list in order.root = self.__rootcurr = root[1] # start at the first nodewhile curr is not root:yield curr[2] # yield the curr[KEY]curr = curr[1] # move to next nodedef __reversed__(self):'od.__reversed__() <==> reversed(od)'# Traverse the linked list in reverse order.root = self.__rootcurr = root[0] # start at the last nodewhile curr is not root:yield curr[2] # yield the curr[KEY]curr = curr[0] # move to previous nodedef clear(self):'od.clear() -> None. Remove all items from od.'root = self.__rootroot[:] = [root, root, None]self.__map.clear()dict.clear(self)# -- the following methods do not depend on the internal structure --def keys(self):'od.keys() -> list of keys in od'return list(self)def values(self):'od.values() -> list of values in od'return [self[key] for key in self]def items(self):'od.items() -> list of (key, value) pairs in od'return [(key, self[key]) for key in self]def iterkeys(self):'od.iterkeys() -> an iterator over the keys in od'return iter(self)def itervalues(self):'od.itervalues -> an iterator over the values in od'for k in self:yield self[k]def iteritems(self):'od.iteritems -> an iterator over the (key, value) pairs in od'for k in self:yield (k, self[k])update = MutableMapping.update__update = update # let subclasses override update without breaking __init____marker = object()def pop(self, key, default=__marker):'''od.pop(k[,d]) -> v, remove specified key and return the correspondingvalue. If key is not found, d is returned if given, otherwise KeyErroris raised.'''if key in self:result = self[key]del self[key]return resultif default is self.__marker:raise KeyError(key)return defaultdef setdefault(self, key, default=None):'od.setdefault(k[,d]) -> od.get(k,d), also set od[k]=d if k not in od'if key in self:return self[key]self[key] = defaultreturn defaultdef popitem(self, last=True):'''od.popitem() -> (k, v), return and remove a (key, value) pair.Pairs are returned in LIFO order if last is true or FIFO order if false.'''if not self:raise KeyError('dictionary is empty')key = next(reversed(self) if last else iter(self))value = self.pop(key)return key, valuedef __repr__(self, _repr_running={}):'od.__repr__() <==> repr(od)'call_key = id(self), _get_ident()if call_key in _repr_running:return '...'_repr_running[call_key] = 1try:if not self:return '%s()' % (self.__class__.__name__,)return '%s(%r)' % (self.__class__.__name__, self.items())finally:del _repr_running[call_key]def __reduce__(self):'Return state information for pickling'items = [[k, self[k]] for k in self]inst_dict = vars(self).copy()for k in vars(OrderedDict()):inst_dict.pop(k, None)if inst_dict:return (self.__class__, (items,), inst_dict)return self.__class__, (items,)def copy(self):'od.copy() -> a shallow copy of od'return self.__class__(self)@classmethoddef fromkeys(cls, iterable, value=None):'''OD.fromkeys(S[, v]) -> New ordered dictionary with keys from S.If not specified, the value defaults to None.'''self = cls()for key in iterable:self[key] = valuereturn selfdef __eq__(self, other):'''od.__eq__(y) <==> od==y. Comparison to another OD is order-sensitivewhile comparison to a regular mapping is order-insensitive.'''if isinstance(other, OrderedDict):return dict.__eq__(self, other) and all(_imap(_eq, self, other))return dict.__eq__(self, other)def __ne__(self, other):'od.__ne__(y) <==> od!=y'return not self == other# -- the following methods support python 3.x style dictionary views --def viewkeys(self):"od.viewkeys() -> a set-like object providing a view on od's keys"return KeysView(self)def viewvalues(self):"od.viewvalues() -> an object providing a view on od's values"return ValuesView(self)def viewitems(self):"od.viewitems() -> a set-like object providing a view on od's items"return ItemsView(self)

3、默認字典(defaultdict)?

學前需求：

1 2	有如下值集合 [11,22,33,44,55,66,77,88,99,90...]，將所有大于?66?的值保存至字典的第一個key中，將小于?66?的值保存至第二個key的值中。 即： {'k1': 大于66?,?'k2': 小于66}

values = [11, 22, 33,44,55,66,77,88,99,90]my_dict = {}for value in values:if value>66:if my_dict.has_key('k1'):my_dict['k1'].append(value)else:my_dict['k1'] = [value]else:if my_dict.has_key('k2'):my_dict['k2'].append(value)else:my_dict['k2'] = [value] from collections import defaultdictvalues = [11, 22, 33,44,55,66,77,88,99,90]my_dict = defaultdict(list)for value in values:if value>66:my_dict['k1'].append(value)else:my_dict['k2'].append(value)

defaultdict是對字典的類型的補充，他默認給字典的值設置了一個類型。

class defaultdict(dict):"""defaultdict(default_factory[, ...]) --> dict with default factoryThe default factory is called without arguments to producea new value when a key is not present, in __getitem__ only.A defaultdict compares equal to a dict with the same items.All remaining arguments are treated the same as if they werepassed to the dict constructor, including keyword arguments."""def copy(self): # real signature unknown; restored from __doc__""" D.copy() -> a shallow copy of D. """passdef __copy__(self, *args, **kwargs): # real signature unknown""" D.copy() -> a shallow copy of D. """passdef __getattribute__(self, name): # real signature unknown; restored from __doc__""" x.__getattribute__('name') <==> x.name """passdef __init__(self, default_factory=None, **kwargs): # known case of _collections.defaultdict.__init__"""defaultdict(default_factory[, ...]) --> dict with default factoryThe default factory is called without arguments to producea new value when a key is not present, in __getitem__ only.A defaultdict compares equal to a dict with the same items.All remaining arguments are treated the same as if they werepassed to the dict constructor, including keyword arguments.# (copied from class doc)"""passdef __missing__(self, key): # real signature unknown; restored from __doc__"""__missing__(key) # Called by __getitem__ for missing key; pseudo-code:if self.default_factory is None: raise KeyError((key,))self[key] = value = self.default_factory()return value"""passdef __reduce__(self, *args, **kwargs): # real signature unknown""" Return state information for pickling. """passdef __repr__(self): # real signature unknown; restored from __doc__""" x.__repr__() <==> repr(x) """passdefault_factory = property(lambda self: object(), lambda self, v: None, lambda self: None) # default"""Factory for default value called by __missing__()."""

4、可命名元組(namedtuple)?

根據nametuple可以創建一個包含tuple所有功能以及其他功能的類型。

1 2 3

import?collections Mytuple?=?collections.namedtuple('Mytuple',['x',?'y',?'z'])

class Mytuple(__builtin__.tuple)| Mytuple(x, y)| | Method resolution order:| Mytuple| __builtin__.tuple| __builtin__.object| | Methods defined here:| | __getnewargs__(self)| Return self as a plain tuple. Used by copy and pickle.| | __getstate__(self)| Exclude the OrderedDict from pickling| | __repr__(self)| Return a nicely formatted representation string| | _asdict(self)| Return a new OrderedDict which maps field names to their values| | _replace(_self, **kwds)| Return a new Mytuple object replacing specified fields with new values| | ----------------------------------------------------------------------| Class methods defined here:| | _make(cls, iterable, new=<built-in method __new__ of type object>, len=<built-in function len>) from __builtin__.type| Make a new Mytuple object from a sequence or iterable| | ----------------------------------------------------------------------| Static methods defined here:| | __new__(_cls, x, y)| Create new instance of Mytuple(x, y)| | ----------------------------------------------------------------------| Data descriptors defined here:| | __dict__| Return a new OrderedDict which maps field names to their values| | x| Alias for field number 0| | y| Alias for field number 1| | ----------------------------------------------------------------------| Data and other attributes defined here:| | _fields = ('x', 'y')| | ----------------------------------------------------------------------| Methods inherited from __builtin__.tuple:| | __add__(...)| x.__add__(y) <==> x+y| | __contains__(...)| x.__contains__(y) <==> y in x| | __eq__(...)| x.__eq__(y) <==> x==y| | __ge__(...)| x.__ge__(y) <==> x>=y| | __getattribute__(...)| x.__getattribute__('name') <==> x.name| | __getitem__(...)| x.__getitem__(y) <==> x[y]| | __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)| | __iter__(...)| x.__iter__() <==> iter(x)| | __le__(...)| x.__le__(y) <==> x<=y| | __len__(...)| x.__len__() <==> len(x)| | __lt__(...)| x.__lt__(y) <==> x<y| | __mul__(...)| x.__mul__(n) <==> x*n| | __ne__(...)| x.__ne__(y) <==> x!=y| | __rmul__(...)| x.__rmul__(n) <==> n*x| | __sizeof__(...)| T.__sizeof__() -- size of T in memory, in bytes| | count(...)| T.count(value) -> integer -- return number of occurrences of value| | index(...)| T.index(value, [start, [stop]]) -> integer -- return first index of value.| Raises ValueError if the value is not present.Mytuple

5、雙向隊列(deque)

一個線程安全的雙向隊列

class deque(object):"""deque([iterable[, maxlen]]) --> deque objectBuild an ordered collection with optimized access from its endpoints."""def append(self, *args, **kwargs): # real signature unknown""" Add an element to the right side of the deque. """passdef appendleft(self, *args, **kwargs): # real signature unknown""" Add an element to the left side of the deque. """passdef clear(self, *args, **kwargs): # real signature unknown""" Remove all elements from the deque. """passdef count(self, value): # real signature unknown; restored from __doc__""" D.count(value) -> integer -- return number of occurrences of value """return 0def extend(self, *args, **kwargs): # real signature unknown""" Extend the right side of the deque with elements from the iterable """passdef extendleft(self, *args, **kwargs): # real signature unknown""" Extend the left side of the deque with elements from the iterable """passdef pop(self, *args, **kwargs): # real signature unknown""" Remove and return the rightmost element. """passdef popleft(self, *args, **kwargs): # real signature unknown""" Remove and return the leftmost element. """passdef remove(self, value): # real signature unknown; restored from __doc__""" D.remove(value) -- remove first occurrence of value. """passdef reverse(self): # real signature unknown; restored from __doc__""" D.reverse() -- reverse *IN PLACE* """passdef rotate(self, *args, **kwargs): # real signature unknown""" Rotate the deque n steps to the right (default n=1). If n is negative, rotates left. """passdef __copy__(self, *args, **kwargs): # real signature unknown""" Return a shallow copy of a deque. """passdef __delitem__(self, y): # real signature unknown; restored from __doc__""" x.__delitem__(y) <==> del x[y] """passdef __eq__(self, y): # real signature unknown; restored from __doc__""" x.__eq__(y) <==> x==y """passdef __getattribute__(self, name): # real signature unknown; restored from __doc__""" x.__getattribute__('name') <==> x.name """passdef __getitem__(self, y): # real signature unknown; restored from __doc__""" x.__getitem__(y) <==> x[y] """passdef __ge__(self, y): # real signature unknown; restored from __doc__""" x.__ge__(y) <==> x>=y """passdef __gt__(self, y): # real signature unknown; restored from __doc__""" x.__gt__(y) <==> x>y """passdef __iadd__(self, y): # real signature unknown; restored from __doc__""" x.__iadd__(y) <==> x+=y """passdef __init__(self, iterable=(), maxlen=None): # known case of _collections.deque.__init__"""deque([iterable[, maxlen]]) --> deque objectBuild an ordered collection with optimized access from its endpoints.# (copied from class doc)"""passdef __iter__(self): # real signature unknown; restored from __doc__""" x.__iter__() <==> iter(x) """passdef __len__(self): # real signature unknown; restored from __doc__""" x.__len__() <==> len(x) """passdef __le__(self, y): # real signature unknown; restored from __doc__""" x.__le__(y) <==> x<=y """passdef __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 """passdef __ne__(self, y): # real signature unknown; restored from __doc__""" x.__ne__(y) <==> x!=y """passdef __reduce__(self, *args, **kwargs): # real signature unknown""" Return state information for pickling. """passdef __repr__(self): # real signature unknown; restored from __doc__""" x.__repr__() <==> repr(x) """passdef __reversed__(self): # real signature unknown; restored from __doc__""" D.__reversed__() -- return a reverse iterator over the deque """passdef __setitem__(self, i, y): # real signature unknown; restored from __doc__""" x.__setitem__(i, y) <==> x[i]=y """passdef __sizeof__(self): # real signature unknown; restored from __doc__""" D.__sizeof__() -- size of D in memory, in bytes """passmaxlen = property(lambda self: object(), lambda self, v: None, lambda self: None) # default"""maximum size of a deque or None if unbounded"""__hash__ = None

注：既然有雙向隊列，也有單項隊列（先進先出 FIFO ）

class Queue:"""Create a queue object with a given maximum size.If maxsize is <= 0, the queue size is infinite."""def __init__(self, maxsize=0):self.maxsize = maxsizeself._init(maxsize)# mutex must be held whenever the queue is mutating. All methods# that acquire mutex must release it before returning. mutex# is shared between the three conditions, so acquiring and# releasing the conditions also acquires and releases mutex.self.mutex = _threading.Lock()# Notify not_empty whenever an item is added to the queue; a# thread waiting to get is notified then.self.not_empty = _threading.Condition(self.mutex)# Notify not_full whenever an item is removed from the queue;# a thread waiting to put is notified then.self.not_full = _threading.Condition(self.mutex)# Notify all_tasks_done whenever the number of unfinished tasks# drops to zero; thread waiting to join() is notified to resumeself.all_tasks_done = _threading.Condition(self.mutex)self.unfinished_tasks = 0def task_done(self):"""Indicate that a formerly enqueued task is complete.Used by Queue consumer threads. For each get() used to fetch a task,a subsequent call to task_done() tells the queue that the processingon the task is complete.If a join() is currently blocking, it will resume when all itemshave been processed (meaning that a task_done() call was receivedfor every item that had been put() into the queue).Raises a ValueError if called more times than there were itemsplaced in the queue."""self.all_tasks_done.acquire()try:unfinished = self.unfinished_tasks - 1if unfinished <= 0:if unfinished < 0:raise ValueError('task_done() called too many times')self.all_tasks_done.notify_all()self.unfinished_tasks = unfinishedfinally:self.all_tasks_done.release()def join(self):"""Blocks until all items in the Queue have been gotten and processed.The count of unfinished tasks goes up whenever an item is added to thequeue. The count goes down whenever a consumer thread calls task_done()to indicate the item was retrieved and all work on it is complete.When the count of unfinished tasks drops to zero, join() unblocks."""self.all_tasks_done.acquire()try:while self.unfinished_tasks:self.all_tasks_done.wait()finally:self.all_tasks_done.release()def qsize(self):"""Return the approximate size of the queue (not reliable!)."""self.mutex.acquire()n = self._qsize()self.mutex.release()return ndef empty(self):"""Return True if the queue is empty, False otherwise (not reliable!)."""self.mutex.acquire()n = not self._qsize()self.mutex.release()return ndef full(self):"""Return True if the queue is full, False otherwise (not reliable!)."""self.mutex.acquire()n = 0 < self.maxsize == self._qsize()self.mutex.release()return ndef put(self, item, block=True, timeout=None):"""Put an item into the queue.If optional args 'block' is true and 'timeout' is None (the default),block if necessary until a free slot is available. If 'timeout' isa non-negative number, it blocks at most 'timeout' seconds and raisesthe Full exception if no free slot was available within that time.Otherwise ('block' is false), put an item on the queue if a free slotis immediately available, else raise the Full exception ('timeout'is ignored in that case)."""self.not_full.acquire()try:if self.maxsize > 0:if not block:if self._qsize() == self.maxsize:raise Fullelif timeout is None:while self._qsize() == self.maxsize:self.not_full.wait()elif timeout < 0:raise ValueError("'timeout' must be a non-negative number")else:endtime = _time() + timeoutwhile self._qsize() == self.maxsize:remaining = endtime - _time()if remaining <= 0.0:raise Fullself.not_full.wait(remaining)self._put(item)self.unfinished_tasks += 1self.not_empty.notify()finally:self.not_full.release()def put_nowait(self, item):"""Put an item into the queue without blocking.Only enqueue the item if a free slot is immediately available.Otherwise raise the Full exception."""return self.put(item, False)def get(self, block=True, timeout=None):"""Remove and return an item from the queue.If optional args 'block' is true and 'timeout' is None (the default),block if necessary until an item is available. If 'timeout' isa non-negative number, it blocks at most 'timeout' seconds and raisesthe Empty exception if no item was available within that time.Otherwise ('block' is false), return an item if one is immediatelyavailable, else raise the Empty exception ('timeout' is ignoredin that case)."""self.not_empty.acquire()try:if not block:if not self._qsize():raise Emptyelif timeout is None:while not self._qsize():self.not_empty.wait()elif timeout < 0:raise ValueError("'timeout' must be a non-negative number")else:endtime = _time() + timeoutwhile not self._qsize():remaining = endtime - _time()if remaining <= 0.0:raise Emptyself.not_empty.wait(remaining)item = self._get()self.not_full.notify()return itemfinally:self.not_empty.release()def get_nowait(self):"""Remove and return an item from the queue without blocking.Only get an item if one is immediately available. Otherwiseraise the Empty exception."""return self.get(False)# Override these methods to implement other queue organizations# (e.g. stack or priority queue).# These will only be called with appropriate locks held# Initialize the queue representationdef _init(self, maxsize):self.queue = deque()def _qsize(self, len=len):return len(self.queue)# Put a new item in the queuedef _put(self, item):self.queue.append(item)# Get an item from the queuedef _get(self):return self.queue.popleft()

迭代器和生成器

一、迭代器

對于Python 列表的 for 循環，他的內部原理：查看下一個元素是否存在，如果存在，則取出，如果不存在，則報異常?StopIteration。（python內部對異常已處理）

class listiterator(object)| Methods defined here:| | __getattribute__(...)| x.__getattribute__('name') <==> x.name| | __iter__(...)| x.__iter__() <==> iter(x)| | __length_hint__(...)| Private method returning an estimate of len(list(it)).| | next(...)| x.next() -> the next value, or raise StopIteration

二、生成器

range不是生成器 和 xrange 是生成器

readlines不是生成器 和 xreadlines 是生成器

1 2 3 4

>>>?print?range(10) [0,?1,?2,?3,?4,?5,?6,?7,?8,?9] >>>?print?xrange(10) xrange(10)

生成器內部基于yield創建，即：對于生成器只有使用時才創建，從而不避免內存浪費

1 2 3 4 5 6 7 8 9 10 11

練習：<br>有如下列表： ????[13,?22,?6,?99,?11] 請按照一下規則計算： 13?和?22?比較，將大的值放在右側，即：[13,?22,?6,?99,?11] 22?和?6?比較，將大的值放在右側，即：[13,?6,?22,?99,?11] 22?和?99?比較，將大的值放在右側，即：[13,?6,?22,?99,?11] 99?和?42?比較，將大的值放在右側，即：[13,?6,?22,?11,?99,] 13?和?6?比較，將大的值放在右側，即：[6,?13,?22,?11,?99,] ...

li = [13, 22, 6, 99, 11]for m in range(len(li)-1):for n in range(m+1, len(li)):if li[m]> li[n]:temp = li[n]li[n] = li[m]li[m] = tempprint li

深淺拷貝

為什么要拷貝？

1	當進行修改時，想要保留原來的數據和修改后的數據

數字字符串 和 集合 在修改時的差異？?（深淺拷貝不同的終極原因）

1 2 3

在修改數據時： ????數字字符串：在內存中新建一份數據 ?????????集合：修改內存中的同一份數據

對于集合，如何保留其修改前和修改后的數據？

1

在內存中拷貝一份

對于集合，如何拷貝其n層元素同時拷貝？

1

深拷貝

作業

　　開發一個簡單的計算器程序
　　*實現對加減乘除、括號優先級的解析,并實現正確運算?

?

轉載于:https://www.cnblogs.com/weiman3389/p/6224009.html

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