Python 文档

ReferenceTablesPythonKeywordsTableB.1listsPython’skeywords.TableB.1PythonKeywordsaandasbassertcbreakclasscontinuedefdelelifelseexceptexecfinallyforfromglobalifimportinislambdanotorpassprintraisereturntrywhilewithbyielddNoneea.accesskeywordobsoletedinPython1.4.b.NewinPython2.6.c.NewinPython1.5.d.NewinPython2.3.e.NotakeywordbutmadeaconstantinPython2.4.PythonStandardOperatorsandFunctionsPython标准操作符与函数TableB.2representstheoperatorsand(built-inandfactory)functionsthatcanbeusedwithmoststandardPythonobjectsaswellasuser-definedobjectsinwhichyouhaveimplementedtheircorrespondingspecialmethods.TableB.2StandardTypeOperatorsandFunctionsOperator/functionDescriptionResultaStringrepresentation‘‘EvaluatablestringrepresentationstrBuilt-inandfactoryfunctionscmp(obj1,obj2)Comparestwoobjectsintrepr(obj)Evaluatablestringrepresentationstrstr(obj)Printablestringrepresentationstrtype(obj)ObjecttypetypeTableB.2StandardTypeOperatorsandFunctions(continued)operator/functionDescriptionResultaValuecomparisonsLessthanboolGreaterthanbool=Lessthanorequaltobool=Greaterthanorequaltobool==Equaltobool!=NotequaltoboolNotequaltoboolObjectcomparisonsisThesameasboolisnotNotthesameasboolBooleanoperatorsnotLogicalnegationboolandLogicalconjunctionboolorLogicaldisjunctionboola.BooleancomparisonsreturneitherTrueorFalse.NumericTypeOperatorsandFunctions数字类型操作符与函数TableB.3representstheoperatorsand(built-inandfactory)functionsthatapplytoPython’snumericobjects.TableB.3OperatorsandBuilt-inFunctionsforAllNumericTypesOperator/built-inDescriptionintlongfloatcomplexResultaabs()Absolutevalue••••numberachr()Character••str(continued)TableB.3OperatorsandBuilt-inFunctionsforAllNumericTypes(continued)Operator/built-inDescriptionintlongfloatcomplexResultacoerce()Numericcoercion••••tuplecomplex()Complexfactory••••complexfunctiondivmod()Division/modulo••••tuplefloat()Floatfactoryfunction••••floathex()Hexadecimalstring••strint()Intfactoryfunction••••intlong()Longfactoryfunction••••longoct()Octalstring••strord()Ordinal(string)intpow()round()**b+c-c~c**bExponentiation••••number*Multiplication••••number/Classicortruedivision••••number//Floordivision••••number%Modulo/remainder••••numberTableB.3OperatorsandBuilt-inFunctionsforAllNumericTypes(continued)Operator/built-inDescriptionintlongfloatcomplexResulta+Addition••••number-Subtraction••••numberExponentiation••••numberFloatrounding•floatExponentiation••••numberNochange••••numberNegation••••numberBitinversion••int/longBitleftshift••int/longBitrightshift••int/long&BitwiseAND••int/long^BitwiseXOR••int/long|BitwiseOR••int/longa.Aresultof“number”indicatesanyofthenumerictypes,perhapsthesameastheoperands.b.**hasauniquerelationshipwithunaryoperators;seeSection5.5.3andTable5.2.c.Unaryoperator.SequenceTypeOperatorsandFunctions序列类型操作符与函数TableB.4containsthesetofoperators,(built-inandfactory)functions,andbuilt-inmethodsthatcanbeusedwithsequencetypes.TableB.4SequenceTypeOperators,Built-inFunctions,andMethodsOperator,built-infunctionormethodstrlisttuple[](listcreation)•()•““•append()•(continued)TableB.4SequenceTypeOperators,Built-inFunctions,andMethods(continued)Operator,built-infunctionormethodstrlisttuplecapitalize()•center()•chr()•cmp()•••count()••decode()•encode()•endswith()•expandtabs()•extend()•find()•hex()•index()••insert()•isdecimal()•isdigit()•islower()•isnumeric()•isspace()•istitle()•isupper()•join()•TableB.4SequenceTypeOperators,Built-inFunctions,andMethods(continued)Operator,built-infunctionormethodstrlisttuplelen()•••list()•••ljust()•lower()•lstrip()•max()•••min()•••oct()•ord()•pop()•raw_input()•remove()•replace()•repr()•••reverse()•rfind()•rindex()•rjust()•rstrip()•sort()•split()•(continued)TableB.4SequenceTypeOperators,Built-inFunctions,andMethods(continued)Operator,built-infunctionormethodstrlisttuplesplitlines()•startswith()•str()•••strip()•swapcase()•split()•title()•tuple()•••type()•••upper()•zfill()•.(attributes)••[](slice)•••[:]•••*•••%•+•••in•••notin•••StringFormatOperatorConversionSymbols字符串格式操作符转换符号TableB.5liststheformattingsymbolsthatcanbeusedwiththestringformatoperator(%).StringFormatOperatorDirectives字符串格式操作符命令Whenusingthestringformatoperator(seeTableB.5),youmayenhanceorfine-tunetheobjectdisplaywiththedirectivesshowninTableB.6.TableB.5StringFormatOperatorConversionSymbolsFormatSymbolConversion%cCharacter(integer[ASCIIvalue]orstringoflength1)%raStringconversionviarepr()priortoformatting%sStringconversionviastr()priortoformatting%d/%iSigneddecimalinteger%ubUnsigneddecimalinteger%ob(Unsigned)octalinteger%xb/%Xb(Unsigned)hexadecimalinteger(lower/UPPERcaseletters)%e/%EExponentialnotation(withlowercase’e’/UPPERcase’E’)%f/%FFloatingpointrealnumber(fractiontruncatesnaturally)%g/%GTheshorterof%eand%f/%E%and%F%%%Percentcharacter(%)unescapeda.NewinPython2.0;likelyuniqueonlytoPython.b.%u/%o/%x/%XofnegativeintwillreturnasignedstringinPython2.4+.TableB.6FormatOperatorAuxiliaryDirectivesSymbolFunctionality*Argumentspecifieswidthorprecision-Useleftjustification+Useaplussign(+)forpositivenumbersspUsespace-paddingforpositiv