python入门教程1Python是一个高效的语言读和写操作都很简单就像普

Python1----PythonPythonPythonPython#Writeyourcodebelow!my_variable=1031Python里面有三种数据类型 ge,floats,2Python31my_int2my_float3my_bool#Setthevariablestothevalueslistedintheinstructions!my_int=7my_float=1.23my_bool=TruePython2：my_int73，#my_intissetto7below.Whatdoyou#willhappenifweresetitto3andprintthemy_int=#Changethevalueofmy_intto3online8!my_int=3#Here'ssomecodethatwillprintmy_inttotheconsole:#Theprintkeywordwillbecoveredindetailsoon!printPyhton的和英语很Python里面利用空格在分3defspam():eggs=12returneggsprintPython2defspam():eggs=12returneggsprint2spamTrue，eggsFalsespam=Trueeggs=2#thisisacommentsforPythonmysterious_variable=42Python2thisisaPythoncoursea=Python6种算术运算符+,-,*,/,**(幂2count_to1+2#Setcount_toequalto1plus2online3!count_to=1+2printPythonx^m2eggs100#Seteggsequalto100usingexponentiationonline3!eggs=10**2print1

12monty3python4monty_pythonpython#thisisaPythonmonty=Truepython=1.234monty_python=Python2----Tip1meal44.50#Assignthevariablemealthevalue44.50online3!meal=44.501tax6.75%meal=44.50tax=6.75/1001tip15%#You'realmostthere!Assignthetipvariableonline5.meal=44.50tax=tip=1mealmeal+meal*tax#Reassignmealonline7!meal=44.50tax=tip=meal=#Assignthevariabletotalonline8!meal=44.50tax=tip=meal=meal+meal*taxtotal=meal+meal*tipprint("%.2f"%total)Python3----StringsandConsoleString是通过''""3brian"Alwayslookonthebrightsideof#Setthevariablebrianonlinebrian="Alwayslookonthebrightsideof1123#Assignyourvariablesbelow,eachonitsownline!caesar="Graham"praline="John"viking=#PutyourvariablesabovethislineprintcaesarprintpralineprintvikingPython是通过\2'Help!Help!I'mbeingrepressed!'I'm#Thestringbelowisbroken.Fixitusingtheescapebackslash!'Help!Help!\'\mbeingrepressed!'2fifth_letterMONTYThestring"PYTHON"hassixcharacters,numbered0to5,asshownbelow:|P|Y|T|H|O|N Soifyouwanted"Y",youcouldjusttype"PYTHON"[1](alwaysstartcountingfrom0!)fifth_letter=print2parrot"NorweigianBlueparrotparrot="Norwegianprint2parrotparrot="NorwegianBlue"printparrot.lower()2parrotparrot="norwegianblue"printparrot.upper()pi3.14pi"""Declareandassignyourvariableonline4,thencallyourmethodonline5!"""pi=print2Stringministrylen(upper()，ministry="TheMinistryofSillyprintlen(ministry)printministry.upper()print2print"MontyPython""""lPythontoprint"MontyPython"totheconsoleonline4!"""print"Monty1print2练习：把变量the_machine_goes值赋值"!"，然后打印出"""Assignthestring"!"tothevariablethe_machine_goesline5,thenprintitoutonlinethe_machine_goes="!"printthe_machine_goes2"Spam"and"eggs#Printtheconcatenationof"Spamandeggs"onlineprint"Spam"+"and"+2str()3.14#Turn3.14intoastringonlineprint"Thevalueofpiisaround"+12%sstring_1="Camelot"string_2="ce"print"Let'snotgoto%s.'Tisasilly%s."%(string_1,#Writeyourcodebelow,startingonlinemy_string=printlen(my_string)printmy_string.upper()Python4----Dateand21now2now<spanstyle="font-size:18px">fromdatetimeimportdatetimenow=datetime.now()print2datetime.now<spanstyle="font-size:18px">fromdatetimeimportdatetimenow=datetime.now()printnow.monthprintnow.dayprint2mm//dd//yyyy<spanstyle="font-size:18px">fromdatetimeimportdatetimenow=datetime.now()print2hh:mm:ss<spanstyle="font-size:18px">fromdatetimeimportdatetimenow=datetime.now()print1<spanstyle="font-size:18px">fromdatetimeimportdatetimenow=datetime.now()printstr(now.month)+"/"+str(now.day)+"/"+str(now.year)+"+str(now.hour)+":"+str(now.minute)+":"+ 入门教程5 ControlFlowPython62True31bool_one17<2bool_two100==33*3+3bool_two19<=4bool_four-22>=-5bool_five99!=#AssignTrueorFalseasappropriateonthelinesbelow!bool_one=17<118%100bool_two=100==33*3+1bool_three=19<=2**4bool_four=-22>=-18bool_five=99!=21bool_one20+->2bool_two==3bool_two1**2**3bool_four40/20*4bool_five100**0.5#AssignTrueorFalseasappropriateonthelinesbelow!bool_one=20+-10*2>10%3%2bool_two=(10+17)**2==3**6bool_three=1**2**3<=-(-(-1))bool_four=40/20*4>=-4**2bool_five=100**0.5!=6+42#Createcomparativestatementsasappropriateonthelines#Makemetrue!bool_one=1<=2#Makemefalse!bool_two=1>#Makemetrue!bool_three=1!=2#Makemefalse!bool_four=2>#Makemetrue!bool_five=4<5andandTrue21bool_oneFalseand2bool_two22and43bool_three19%4300/10/10and

4bool_four(1**2)2**0and10%1020-5bool_fiveTrueandbool_one=Falseandbool_two=-(-(-(-2)))==-2and4>=bool_three=19%4!=300/10/10andbool_four=-(1**2)<2**0and10%10<=20-bool_five=Trueand2bool_one2**3108%100or'Cleese'

bool_twoTrueorbool_three100**0.550orbool_fourTrueorbool_five1**100100**1or3*2*1bool_one=2**3==108%100or'Cleese'=='Kingbool_two=Trueorbool_three=100**0.5>=50orbool_four=Trueorbool_five=1**100==100**1or3*2*1!=not,notTrueFalse，notFalse2bool_onenotbool_twonot3**4<bool_threenot10%3<=

bool_fournot3**2+4**2!=bool_fivenotnotbool_one=notbool_two=not3**4<bool_three=not10%3<=bool_four=not3**2+4**2!=bool_five=notnot2bool_oneFalseor(notTrue)andbool_twoFalseand(notTrue)orbool_threeTrueandnot(Falseorbool_fournot(notTrue)orFalseand(notbool_fiveFalseornot(Trueandbool_one=Falseor(notTrue)andbool_two=Falseand(notTrue)orbool_three=Trueandnot(Falseorbool_four=not(notTrue)orFalseand(notbool_five=Falseornot(Trueand1and，or，not#Usebooleanexpressionsasappropriateonthelines#Makemebool_one=not((1and2)or#Makemebool_two=not(not((1and2)or#Makemebool_three=not((1and2)or#Make=not(not((1#Makeme=not(not((1if的格式如下,if8<print"Eightislessthan3elifelse，if8<print"Igetprinted!"elif8>9:print"Idon'tgetprint"Ialsodon'tget4responseresponse=answer=ifanswer==print"ThisistheVerbalAbuseRoom,youheapofparrotdrop#Willtheaboveprintstatementprinttothe#Setresponseto'Y'ifyouthinkso,and'N'ifyouthinkif#blocklineone#blocklinetwo#etcedefusing_control_once():if1>0:return"Successdefusing_control_again():if1>0:return"Successprintusing_control_once()printelse2elseanswer="'Tisbutadefifanswer=="'Tisbuta

returnreturn #Makesurethisreturnsdefifanswer=="Goaway,orIshalltauntyouasecondtime!":returnTruereturn #Makesurethisreturns2answer5，answer5defgreater_less_equal_5(answer):ifanswer>5:return1elifanswer<return-returnprintgreater_less_equal_5(4)printgreater_less_equal_5(5)print1def#Startcodingif1<2andnotFalse:returnTrueelif1==1or1!=2or1<2or1<=2or1>2or1>=2:returnTruereturnPython 1练习：使用Python来输出这句话" etotheEnglishtoPigLatinprint etotheEnglishtoPigLatinPython的输入，Pythonraw_input2nameraw_ijnput("what'syourname")what'syournamename3originalprint" etotheEnglishtoPigLatintranslator!"original=raw_input(" etothePython:")2print" etotheEnglishtoPigLatintranslator!"original=raw_input(" etothePython:")iflen(original)>0:printoriginalprint如果是数字，则isalpha的值为false，否则为2 一个变量为x="123"，那么x.isalpha()是3originalprint" etotheEnglishtoPigLatintranslator!"original=raw_input(" etothePython:")iforiginal.isalpha():print"True"print1print" etotheEnglishtoPigLatintranslator!"original=raw_input(" etothePython:")if

printprintoriginal=raw_input(" etothePython:")iflen(y)==0:printprint"no1Stringlower()2pyg='ay'

1word2firstwordoriginal=raw_input('Enteraword:')word=original.lower()first=iflen(original)>0andoriginal.isalpha():printoriginalprintpyg='ay'original=raw_input('Enteraword:')word=original.lower()first=iflen(original)>0andiffirst=='a'orfirst=='i'orfirst=='o'orfirst=='u'or==print

printprint

print"vowelprintpyg=original=raw_input('Enteraword:')word=original.lower()first=word[0]new_word=word+pygiflen(original)>0andiffirst=='a'orfirst=='i'orfirst=='o'orfirst=='u'or==

printprintprintStrings="foo"s[0:2]就是2ifnew_wordword1pyg='ay'original=raw_input('Enteraword:')word=original.lower()first=word[0]new_word=word+pygiflen(original)>0andiffirst=='a'orfirst=='i'orfirst=='o'orfirst=='u'or==new_word=

printprintprintPython 2def"""Prints'Ni!'totheconsole."""print"Ni!"3"Eggs!"，#Defineyourspamfunctionstartingonline5.You#canleavethecodeonline11alonefornow--we'll#exinitsoon!def"""thisisazhushi"""print"Eggs!"#Definethespamfunctionabovethisline.2spam(10)def"""Returnsthesquareofanumber."""squared=n**2print"%dsquaredis%d."%(n,squared)returnsquared#Callthesquarefunctiononline9!Makesureto#includethenumber10betweentheparentheses.2no_one(sentence)的使用，传入字符串作为参数defno_one(sentence):printsentenceno_one("TheSpanish3base,exponent374[python]viewincopydefpower(base,exponent): #Addyourparametershere!result=base**exponentprint"%dtothepowerof%dis%d."%(base,exponent, #Addyourarguments介绍了*的用法，比如我们传入一个字符串，那么我们可以使用*name接收，然后可以namename，可以是任何的名字2def"""PrintsoutyourfavoriteactorS(plural!)"""print"Yourfavoriteactorsare:",namefavorite_actors("MichaelPalin","JohnCleese","Graham2defreturnn*defreturnfun_one(m)+3defone_good_turn(n):returnn+1defreturnn+1cubeFalseby_three(9)defreturndefif(num%3==returnreturn2mathprintsqrt(253math，importprintmath.sqrt(25math#AskPythontoprintsqrt(25)online3.importmathprint 2frommoduleimport3mathsqrt#Import*just*thesqrtfunctionfrommathonline3!frommathimportsqrtprint frommoduleimport*2math#Import*everything*fromthemathmoduleonline3!frommathimport*print 2import #Importsthematheverything=dir(math)#Setseverythingtoalistofthingsfrommathprinteverything #Prints'emall!1max(max(1,2,3)3（min2max()3max#Setumtothemaxvalueofanysetofnumbersonline3!um=max(4,0,-3,78)print2abs(-42)的值absolute=abs(-42)printabsolutetype函数的使用，typeintfloatprinttype(42)printtype(4.2)printtype('spam')printtype({'Name':'JohnCleese'})printtype((1,2))<type<type<type<type<type#Printoutthetypesofaninteger,afloat,#andastringonseparatelinesbelow.printtype(4)printtype(4.2)printtype('spam') 入门教程8----PythonListsandPython2list_name[item1,item2]，PythonC像

empty_listzoo_animals=["pangolin","cassowary","sloth","dog"];#Oneanimalismissing!iflen(zoo_animals)>print"Thefirstanimalatthezooisthe"+zoo_animals[0]print"Thesecondanimalatthezooisthe"+zoo_animals[1]print"Thethirdanimalatthezooisthe"+zoo_animals[2]print"Theanimalatthezooisthe"+zoo_animals[3]numbers=[5,6,7,print"Addingthenumbersatindices0andprintnumbers[0]+print"Addingthenumbersatindices1and3..."#Yourcodehere!printnumbers[1]+

lisy_name[2]2zoo_animals=["pangolin","cassowary","sloth","tiger"]#Lastnightourzoo'sslothbrutallyattacked#thepoortigerandateit#Theferociousslothhasbeenrecedbyafriendlyhyena.zoo_animals[2]="hyena"#Whatshallfillthevoidleftbyourdeardepartedtiger?#Yourcodehere!zoo_animals[3]=listitemsuitcasesuitcase=[]#Yourcodehere!#Setthistothelengthofsuitcaselist_length=len(suitcase)print"Thereare%ditemsinthesuitcase."%(list_length)printsuitcaselistlist_name[a:b]ab之前的my_list[1,2,3,4my_list[1:3]得到的将是my_list=[0,1,2,3]my_slice=my_list[1:3]printmy_list#Prints[0,1,2,3]printmy_slice#Prints[1,#Grabsthefirsttwoitems#Grabsthethroughsuitcase=["sunglasses","hat","passport","laptop","suit",#Thefirsttwoitemsfirst=#Thirdanditemsmiddle=suitcase[2:4]#Thelasttwoitemslast=suitcase[4:]animals=#Thefirstthreecharactersofanimalscat=animals[:3]#Thethroughsixthcharactersdog=animals[3:6]#Fromtheseventhcharactertotheendfrog=animals[6:],list_name.insert(index,item)练习：使用printlist_name，animals=["aardvark","badger","duck","emu","fennecfox"]#Useindex()tofind"duck"duck_index=#Yourcodehere!#Observewhatprintsaftertheinsertoperationprintanimals

forvariablein练习：打印列表的每一个元素的值my_list=fornumberinmy_list:#Yourcodehereprint2*number

beatles=["john","paul","george","ringo","stuart"]print>>square_liststart_list=[5,3,1,2,4]square_list=[]#Yourcodefornumbersinstart_list:printforIindeciKeydec[i]value2d={'key1'1,'key2':2,'key3'3value练习：打印出'Sloth'和'BurmesePython'#Assigningadictionarywiththreekey-valuepairstoresidents:residents={'Puffin':104,'Sloth':105,'BurmesePython':106}#PrintsPuffin'sroomnumberprintresidents['Puffin']#Yourcodeprintprintresidents['Burmese={}字典里面添加一个键值对或者是改变已有key的value使用这种方法=2练习：至少添加3个键值对到字典#Emptydictionary={}#Addingnewkey-valuepair['ChickenAlfredo']=14.50print['Chicken#Yourcodehere:Addsomedish-pricepairsto!["a"]=1["b"]=["c"]=#printyouprint"Thereare"+str(len())+"itemsonthe."print2deldict_name[keykey3key"Sloth"和"BengalTiger"，key"RockhopperPenguinval#key-animal_name:value-zoo_animals={'Unicorn':'CottonCandyHouse','Sloth':'RainExhibit','BengalTiger':'JungleHouse','AtlanticPuffin':'ArcticExhibit','RockhopperPenguin':'ArcticExhibit'}#Adictionary(orlist)declarationmaybreakacrossmultiplelines#Removingthe'Unicorn'entry.(Unicornsareincrediblyexpensive.)delzoo_animals['Unicorn']#Yourcodedeldelzoo_animals["BengalTiger"]zoo_animals["RockhopperPenguin"]="aa"#printyoucodeprint2比如my_dict={"o":["h","e","l","l","o"]}，那么key为"o"对应index1"e"3keyvaluelist比如my_dict["o"].sort()41inventorykey'pocket'，["seas","strangeberry",2key'pocketvalue3inventorykey'backpack'4inventorykey'gold'value#Assignedanewlistto'pouch'keyinventory={'gold':500,'pouch':['flint','twine','backpack':['xylophone','dagger','bedroll','bread#Addingakey'burlapbag'andassigningalisttoitinventory['burlapbag']=['apple','smallruby','three-toedsloth']#Sortingthelistfoundunderthekey'pouch'#Herethedictionaryaccessexpressiontakestheceofalist#Yourcodeinventory['pocket']=["seas","strangeberry","lint"]delinventory['backpack']inventory['gold']=[500,Python语言内置了sortListL=[6,5,1,3,4,printL———-RunPythonProgram———[1,2,3,4,5,龄排序，等等）。在Java语言中，我们可以自定义Comparator来实现，Python中也提供List2-tuple，tupleString类型的keyword，第二个元素为该字符串对应的权重（int类型），希望按照权重排序（从高到低），则可以这样：defmy_cmp(E1,return-cmp(E1[1],E2[1]) #compareweightofeach2-tuple#returnthenegativeresultofbuilt-incmp#thuswegetthedescendL=[('a',0),('b',1),('c',2),('d',printL———-RunPythonProgram———[('d',3),('c',2),('b',1),('a',fromrandomimportdefmy_cmp(E1,print‘E1:’,E1,‘E2:’,returncmp(E1,L=range(0,10)printL———-RunPythonProgram———[5,3,7,6,2,8,9,4,1,3573756567262523858796984643E1:E1:4E2:1614131205030201sort不是采用的分治法（devide-and-conqure）6开始，新元素不样，可以把时间代价从nlog(n)。至此，我们可以认为，built-in的sort方法，采用的是“二分法插入排序”（binaryL=[0,1,2,3,4,5,6,7,8,9,———-RunPythonProgram———102132435465768798E1:10E2:L=[0,1,2,3,4,5,6,8,7,9,———-RunPythonProgram———-E1:1E2:0E1:2E2:E1:E1:3E2:43546586787476789497985898Lstsot2：Pythonurl编码：urllib.quote(string[,safe])，除了三个符号“_print print

pythonopenfile_handler=Tabler以读方式打开文件，可文件信息wabWindowsDosUnixTableFalse。whereoffset ；1表示当前位置；2表示文件结尾。f.sizestring readread=whileprintreadread=read.write("thank1111print'readlines print'readline()print print'read()print#-*-encoding:UTF-8-filehandler=open('c:\\111.txt','r') printprint'listall textlist=forlineinprintprint'seek(15)function' print l()print print 62010-07-28(1list普通的链表，初始化后可以通过特定方法动态增加元素。定义方式：arr=[元素](2Tuple固定的数组，一旦定义后，其元素个数是不能再改变的。定义方式：arr=(元素)(2DictionaryHash数组。定义方式：arr={k:v}(1)lista=arr=arriforiinrange(10),1iforinxx这个必须放在第一个位置，否则要先i，如arr=[iforiinrange(5),jforjinrange(5),i=j=arr=[iforiinrange(5),jforjinrange(5),c、del:startendistartandiend)del删除数组里的指定元素deldelarr[0,2]newarr=arr[0,2]fork,vinenumerate(arr):printk,varr.insert(n,值)arr数组元素+=(2)TupleTuplelisttuple就不能以任何方式改变它。ta","b","c",d #[1]>>>('a','b','c','d', #[2] #[3]-10 #[4]1:3i>=1andi<3('b',Tupletupleappendextend、inserttupleremovepoptupleindex方法（index是查找而不是索引，索引直接用下标即可，如：t[0]tupleTuplelist操作速度快。如果您定义了一个值的常量集,并且唯一要用它做的是不断地遍历它,请使用tuple代替list。“写保护”,tuplelist如同拥有一个隐含的assert语句,说明这一数据是常量。如果必须要改变这些值,则需要执行tuple到list的转换(需要使用一个特殊的函数)。还记得我dictionarykeys可以是字符串,“其它几种类型”吗Tuples就是这Tuplesdictionarykey,list不行。实际上,事情要比这更复杂。Dictionarykey必须是不可变的。Tuple本身是不可改变的,但是如果您有一个list的tuple,dictionarykey就是不安全的。只有字符串,整数或其它对dictionary安全的tuple才可以用作dictionarykey。Tuplelistt=list(tarr=tuple(arr(2)Dictionary哈希数组)#Dictionary的用法比较简单它可以 #下面例子中a是整数，b是字符串,c是数组，这个例子充分说明哈希数组的适用性。dict_arr={'a':100,'b':'boy','c':['o','p','q']}dict_arr['d']=#输出所有的key#输出所有的valueimporttypesforkinv=iftype(v)istypes.ListType:listprintk,'---forkk,vvinenumerate(v):printkk,vvprint'---'list的方法L.append(var追加元素L.pop(varlist中删除之L.remove(var)#删除第一次出现的该元素L.count(var)#该元素在列表中出现的个数L.index(var)#该元素的位置,无则抛异常L.extend(list)#listlistL上L.sort()#排序L.reverse(list操作符:,+,*a[1:]list[1,2]+[3,4]为[1,2,3,4][2]*4为delL[1]delL[1:3]删除指定下标范围的元素list的L1L#L1L的别名，用CL1操作即对L操作。函数参数就是L1LL1为Llist[<expr1>forkinLif<expr2>2、dictionary（C++dict={‘ob1′:’computer’,‘ob2′:’mouse’,D.get(key0)dict[key]，多了个没有则返回缺省值，0。[]没有则抛异常D.has_key(key)#TRUEFALSED.keys(返回字典键的列表D.update(dict2)D.popitempair，并从字典中删除它。已空则抛异常D.clear()#deldictD.copyD.cmp(dict1,dict2比较字典，(优先级为元素个数、键大小、键值大小)#1，小返回-10dict1dictdict2=dict.copy()tuple=(‘a’,‘b’,‘c’,‘d’,‘e’)可以用list[],:4、string：字符串（即不能修改的字符list）str=“ oMyfriend”in，notin“He”instr“she”notinS.find(substring,[start[,end]]可指范围查找子串，返回索引值，否则返回-1S.rfind(substring,[start[,end]])#反向查找[,)#S.rindex(substring,[start[,end]])#同上反向查找S.count(substring,[startend]]返回找到子串的个数S.capitalize(首字母大写S.lower()#转小写S.upper()#转大写S.swapcaseS.split(strstringlist，以空格切分S.join(listliststringlen(strcmp(“myfriendstr)1max(‘abcxyz’)#寻找字符串中最大的字符min(‘abcxyz’)#寻找字符串中最小的字符oat(str)变成浮点数，float(“1e-1″)0.1int(str)#变成整型，int(“12″)12int(str,basebase进制整型数，int(“11″,2)2long(str)#变成长整型，字符串的格式化（注意其转义字符，大多如C语言的，略str_format参数列表a=>>>a[::2]# teoverthewholelistin2-#>>>a[::- incopyto>>>print"The%(foo)sis%(bar)i."%{'foo':'answer',Theansweris>>>foo,bar='question',123>>>print"The%(foo)sis%(bar)i."%Thequestionis incopyto>>>str(round(1234.5678,->>>str(round(1234.5678,and/or incopyto1.x=is_ok()and"Yes"or"No"#ifx=x=yxyx[:] incopyto>>>x=>>>y=>>>y[2]=>>>[1,2,>>>[1,2,>>>y=>>>y[2]=>>>[1,2,>>>13.13.[1,2,5：pythonExcel读写--原文地址 python环境。import2、打开Excel文件数dataxlrd.open_workbook('excelFile.xls')table=data.sheets()[0] table=data.sheet_by_index(0)#通过索引顺序获取table=data.sheet_by_name(u'Sheet1')#通过名称获取nrows=table.nrowsncols=table.ncolsforiinrange(nrowsprintcell_A1=cell_C4=cell_A1=table.row(0)[0].valuecell_A2=table.col(1)[0].valuerow=col=#0empty,1string2number3date4boolean5errorctype=1value='单元格的值'xf=0#扩展的格式化table.put_cell(rowcol,ctypevalue,xf)table.cell(0,0)#单元格的值'table.cell(0,0).value#单元格的值'Demo代码其实很简单，就是Excel数据1#-*-coding:utf-8-1#-*-coding:utf-8- xdrlibimportdefopen_excel(file=data=returnexceptprint#根据索引获取Excel表格中的数 参数:file：Excel文件路colnameindex：表头列名所在行的所以，by_index：表的索引11defexcel_table_byindex(file=data=tabledata.sheets()[by_index]nrows=table.nrows#行数ncols=table.ncols#列数colnames= table.row_values(colnameindex)list=[]forrownuminrow=ifapp=foriin=return28#根据名称获取Excel表格中的数 参数:file：Excel文件路colnameindex：表头列名所在行的所以，by_name：Sheet129defexcel_table_byname(file=data=table=nrows=table.nrowscolnames listforrownuminrow=ifapp=foriinapp[colnames[i]]=returndeftables=forrowinprinttables=forrowinprintifname=="mainPython原址 介绍及使用示例。本文的内容不包括如何编写高效的正则表达式、如何优化正则表达式，这些请查看其他。注意：本文基于Python2.4完成；如果看到不明白的词汇请记得谷歌或，whatever。Python的一部分。正则表达式是用于处理字符串的强大工具，拥有自己独特的语法以及一个独立的处理引擎，效率上可能不如str自带的方法，但功能十分强大。得益于这一点，在提供了正但也是很好理解的，看下图中的示例以及自己多使用几次就能明白。下图列出了Python支持的正则表达 正则表达式通常用于在文本中查找匹配的字符串。Python里数量词默认是贪婪的（是默认非贪婪），总是尝试匹配尽可能多的字符；非贪婪的则相反，总是尝试匹配尽可能少的字符。例如：正则表达式"a*如果用于查找"ac"，将找到"ab"。而如果使用非贪婪的数量词"a*?，将找到"a"。与大多数编程语言相同，正则表达式里使用作为转义字符，这就可能造成反斜杠困扰。假如你需要匹配文本中的字符4个反斜杠：前两个和后两个分别用于在编程语言里转义成反斜杠，转换成两个反斜杠后再在正则表达式里转义成一个反斜杠。Python表示。同样，匹配一个数字的""""表达式也更直观。 pile(pattern[,flags])中一起介绍。Python通过rere的一般步骤是先将正则表达式的字符串形式编译PatternPattern实例处理文本并获得匹配结果（Match实例），最后使用Match实例获得信息，进行其他的操作。1#encoding:UTF-2import34Pattern5pattern 67Pattern8match=pattern.match('o9ifprint pile(strPattern[,这个方法是Pattern类的工厂方法，用于将字符串形式的正则表达式编译为Pattern对象。第二个参数flag是匹配模式，取值可以使用按位或运算符'|'表示同时生效，比如re.I|re.M。另外，你也可以在regex字符串中指定模式，比如 pile('pattern',re.I|re.M)与 re.I(re.IGNORECASE):忽略大小写（括号内是完整写法，下同M(MULTILINE):多行模式，改变'^'和'$'的行为（参见上图S(DOTALL):点任意匹配模式，改变'.'L(LOCALE):\w\W\b\B\s\SU(UNICODE):\w\W\b\B\s\S\d\D取决于unicodeX(VERBOSE)详细模式。这个模式下正则表达式可以是多行，忽略空白字符，并可以加入注1abpile(r"""\d #theintegral\d#thedecimal#somefractionaldigits""",234re提供了众多模块方法用于完成正则表达式的功能。这些方法可以使用Pattern实例的相应方法替代， pile()代码，但同时也无法复用编译后的Pattern对象。这些方法将在Pattern类的实例方法部分一起介绍。如上面这个例子可以简写为：1m=o',o2printreescape(string)string中的正则表达式元字符如*/+/?等之前加MatchMatch提供的可读属性或方string:re:匹配时使用的Patternpos文本中正则表达式开始搜索的索引。值与Pattern.match()和Pattern.seach()方法的同名参数endposPattern.match()和Pattern.seach()方法的同名lastindex:最后一个获的分组在文本中的索引。如果没有获的分组，将为Nonelastgroup:最后一个获的分组的别名。如果这个分组没有别名或者没有获的分组，将group([group1,0group(0)；没有截获字符串的组返回以元组形式返回全部分组截获的字符串。相当于调用group(1,2,…last)。default表示没有截获字符串None。返回指定的组截获的子串在string中的起始索引（子串第一个字符的索引。group0,1import2m=re.match(r'(\w+)(\w+)(?P<sign>.*)',o34print"m.string:",5print"m.re:",6print"m.pos:",7print"m.endpos:",8print"m.lastindex:",1import2m=re.match(r'(\w+)(\w+)(?P<sign>.*)',o34print"m.string:",5print"m.re:",6print"m.pos:",7print"m.endpos:",8print"m.lastindex:",9print"m.lastgroup:",print"m.group(1,2):",m.group(1,print"m.groups():",print"m.groupdict():",print"m.start(2):",print"m.end(2):",print"m.span(2):",printr"m.expand(r'\2\1\3'):",m.expand(r'\2###output#m.string:o#m.re:<_sre.SRE_Patternobjectat#m.pos:#m.endpos:#m.lastindex:#m.lastgroup:#m.group(1,2): o',#m.groups(): o','world',#m.groupdict():{'sign':#m.start(2):#m.end(2):#m.span(2):(6,#m.expand(r'\2\1\3'):worldPattern不能直接实例化，必须使用 Pattern提供了几个可读属性用于获取表达式的相关信息：pattern:flags:groups:groupindex:以表达式中有别名的组的别名为键、以该组对应的编号为值的字典，没有别名的组不包含importimportp pile(r'(\w+)(\w+)(?P<sign>.*)',print"p.pattern:",p.patternprint"p.flags:",p.flagsprint"p.groups:",p.groupsprint"p.groupindex:",###output###output#p.pattern:(\w+)(\w+)(?P<sign>.*)#p.flags:16#p.groups:#p.groupindex:{'sign':实例方法[|re模块方法match(string[,pos[,endpos]])|re.match(pattern,string[,这个方法将从string的pos下标处起尝试匹配pattern；如果pattern结束时仍可匹配，则返回一个Match对象；如果匹配过程中pattern无法匹配，或者匹配未结束就已到达endposNone。pos和endpos0和len(string)；re.match()无法指定这两个参数，参数flags用于编译pattern时指定匹配模式。注意：这个方法并不是完全匹配。当pattern结束时若string还有剩余字符，仍然视为成功。想要完全2.1search(string[,pos[,endpos]])|re.search(pattern,string[,这个方法用于查找字符串中可以匹配成功的子串。从string的pospattern，如果patternMatch对象；若无法匹配，则将pos1后重新尝试匹配；直到pos=endposNone。#encoding:UTF-8importrePatternpattern search()Nonematch()无法成功匹配match=#encoding:UTF-8importrePatternpattern search()Nonematch()无法成功匹配match= oifMatchprint#split(string[,maxsplit])|re.split(pattern,string[,import按照能够匹配的子串将string分割后返回列表。maxsplitimportppprint###output#['one','two','three','four',findall(string[,pos[,endpos]])|re.findall(pattern,string[,importpimportp print###output#['1','2','3',finditer(string[,pos[,endpos]])|re.fi