super() in Python: What Does It Do? [A Complete Guide]

When you initialize a child class in Python, you can call the super().__init__() method. This initializes the parent class object into the child class. SkiptocontentSoftware,Tech&Codingsimplified.HomeAboutResourcesCoursesSwift&iOSDataSciencePythonCoursePlatformsGraphicDesign&UI/UXAdvertiseHireMeContactMenuHomeAboutResourcesCoursesSwift&iOSDataSciencePythonCoursePlatformsGraphicDesign&UI/UXAdvertiseHireMeContactTwitter Linkedin Medium Github Youtube Home»super()inPython:WhatDoesItDo?super()inPython:WhatDoesItDo?ArtturiJalliInPython,super()methodmakesitpossibletoaccessthemembersofaparentclass.Tounderstandwhatisaparentclass,youneedtoknowwhatclassinheritancemeans.Beforejumpingintothedetails,let’sseeaquickexampleofusingthesuper()method.Forinstance:classPet(): defhello(self):print("Hello,IamaPet") classCat(Pet): defsay(self): super().hello() luna=Cat() luna.say()Output:Hello,IamaPetInthispieceofcode:ThePetclassdefinesamethodcalledhello().TheCatclassinheritsthePetclass.TheCatclassimplementsasay()methodthatcallsthehello()methodfromthePetclass.Thisispossibleviathesuper()method.Inthisguide,wearegoingtotakeadeeperlookathowthesuper()methodworksinPython.Totrulyunderstandsuper(),youneedtounderstandwhatisinheritanceinPython.ClassInheritanceinPython:AQuickIntroductionPythonisanobject-orientedprogramminglanguage.Oneofthemainfeaturesofanobject-orientedlanguagelikePythonisclassinheritance.Pythonsupportsclassinheritance,alsocalledsubclassing.Theideabehindtheclassinheritanceistocreateaparentclass-childclasshierarchy.Inotherwords,themembersoftheparentclassareinheritedtothechildclass.Toputitshort,inheritanceletsyoureusecode.Butwhyreusecode?Youshouldalwaystrytoavoidrepeatingyourselfincode.SometimesyourPythonobjectsarerelatedtooneanother.Inthiscase,itwouldbeuselessifyouhadtorepeatyourselfandre-implementmethodsfromoneclasstoanotherclass.Inthiscase,youcanuseinheritance.AgreatexampleofinheritancewouldbeaPerson–Studentrelationshipinthecode.Lets’ssayyourcodehastwoclasses,PersonandStudent.Asyouknow,eachStudentisalsoaPerson.Thus,itmakessensetoinheritallthepropertiesofaPersontoanStudent.Forexample:classPerson: def__init__(self,name,age): self.name=name self.age=age defintroduce(self): print(f"Hello,mynameis{self.name}.Iam{self.age}yearsold.") classStudent(Person): def__init__(self,name,age,graduation_year): #DOnotworryaboutthenextline,wewillcomebacktoitverysoon! super().__init__(name,age) self.graduation_year=graduation_year defgraduates(self): print(f"{self.name}willgraduatein{self.graduation_year}")NowyoucanusethissetuptocreateStudentobjectsthatcanusethePersonclassesintroduce()method.Forinstance:alice=Student("Alice",30,2023) alice.introduce() alice.graduates()Output:Hello,mynameisAlice.Iam30yearsold. Alicewillgraduatein2023Inthispieceofcode:alice.introuce()iscalledfromtheparentclassofStudent,thatis,Person.alice.graduates()iscalleddirectlyfromtheStudentclassitself.Thisdemonstrateswellhowinheritanceworks.EachStudentisaPerson.ItmakessensetogivethepropertiesofaPersondirectlytotheStudent,insteadofre-implementingthemintheStudentclass.NowyouunderstandwhatinheritanceisinPython.Next,let’stakealookathowthesuper()methodworks.Thesuper()inPythonToaccessparentclasspropertiesfromthesubclass,youneedtousethesuper()method.Thesuper()isanexplicitreferencetothebaseclass.Itlinksyourparentclasstothechildclass.Anythingfoundintheparentclasscanbeaccessedinthechildclassviathesuper()method.Themostcommonexampleofusingthesuper()methodisuponinitialization.Inthepreviouschapter,youalreadysawanexampleofthis.Now,let’stakeadeeperlookathowitworks.Thesuper().__init__()CallinPythonWhenyouinitializeachildclassinPython,youcancallthesuper().__init__()method.Thisinitializestheparentclassobjectintothechildclass.Inadditiontothis,youcanaddchild-specificinformationtothechildobjectaswell.Hereiswhatitgenerallylookslike:classParent: definit(v1,v2): self.v1=v1 self.v2=v2 classChild(Parent): definit(v1,v2,v3): super().__init__(v1,v2) self.v3=v3Here:TheParentclasshaspropertiesv1andv2.Theyareinitializedintheparentclassesinit()method.TheChildclassinhertistheParentclass.TheChildclassinitializestheParentclassobjectTheChildclassalsoinitializesitselfbyspecifyinganewpropertyv3thatonlybelongstoit,nottotheParent.Let’stakealookatamoreconcreteexample.Let’ssaywehaveaclassthatrepresentsaperson.Eachpersonhasanameandage.Furthermore,eachPersonobjecthastheabilitytointroducethemselvesusingtheintroduce()method.HereiswhatthePersonclasslookslike:classPerson: def__init__(self,name,age): self.name=name self.age=age defintroduce(self): print(f"Hello,mynameis{self.name}.Iam{self.age}yearsold.")ThisclassactsasablueprintforcreatingPersonobjectsinourcode.Now,let’ssaywealsowanttorepresentstudentsinourprogram.Todothis,weneedanewclassforstudentobjects.Morespecifically,eachstudentshould:Haveaname,age,andagraduationyear.Beabletointroducethemselves.Tellwhentheyaregoingtograduate.Wecouldwriteacompletelyseparateclasslikethis:classStudent(Person): def__init__(self,name,age,graduation_year): self.name=name self.age=age self.graduation_year=graduation_year defintroduce(self): print(f"Hello,mynameis{self.name}.Iam{self.age}yearsold.") defgraduates(self): print(f"{self.name}willgraduatein{self.graduation_year}")Eventhoughthisworks,thereisaproblem.Thiscodeisnowrepetitive.Theintroduce()methodwasalreadyimplementedinthePersonclass.Also,theinit()methodlooksprettysimilar.Wecanimprovethecodebyusinginheritance.ThefirstthingtonoticeisthateachStudentisalsoaPerson,whichmakessense.ThuswecaninheritthepropertiesofaPersontotheStudentclassdirectly.Let’sthenaddanewmember,graduation_year,totheStudentobject.Inaddition,weneedamethodtodisplaythis.SowhenitcomestoinitializingtheStudentobject,wecan:InitializethePersonobjectintheStudent.Thishappenswiththesuper().__init__()call.ThisgivesthenameandagetotheStudentobject.InitializetheStudent-specificgraduationyear.HereistheimprovedversionoftheStudentclassthatutilizesinheritance.classStudent(Person): def__init__(self,name,age,graduation_year): #1.InitializethePersonobjectinStudent. super().__init__(name,age) #2.Initializethegraduation_year self.graduation_year=graduation_year #AddamethodthattellswhenthisStudentisgoingtograduate. defgraduates(self): print(f"{self.name}willgraduatein{self.graduation_year}")Paycloseattentiontothesuper().__init__(name,age)call.Thiscallsthe__init__()methodoftheparentclass,Person.Inotherwords,itinitializesaPersonobjectintotheStudentobject.Thesuper()MethodinMultipleInheritanceYoucanalsostreamlinetheprocessofinitializingmultipleclasseswiththehelpofthesuper()method.Inotherwords,youcanusethesuper()methodinmultiplesubclassestoaccessthecommonparentclassesproperties.Forinstance,let’screateahierarchysuchthataPersonobjectisinheritedtoStudentandEmployee.Hereishowitlooksincode:classPerson: def__init__(self,name,age): self.name=name self.age=age defintroduce(self): print(f"Hello,mynameis{self.name}.Iam{self.age}yearsold.") #Subclass1. classStudent(Person): def__init__(self,name,age,graduation_year): super().__init__(name,age) self.graduation_year=graduation_year defgraduates(self): print(f"{self.name}willgraduatein{self.graduation_year}") #Subclass2. classEmployee(Person): def__init__(self,name,age,start_year): super().__init__(name,age) self.start_year=start_year defgraduates(self): print(f"{self.name}startedworkingin{self.start_year}")AccessRegularInheritedMethodswithSuper()Inacoupleoflastexamples,yousawhowtousethesuper()methodtocalltheinitializeroftheparentclass.Itisimportanttonoticeyoucanaccessanyothermethodtoo.Forexample,let’smodifythePerson-Studentexampleabit.Let’screateaninfo()methodfortheStudentclass.Thismethod:Callstheintroduce()methodfromtheparentclasstointroduceitself.Showsthegraduationyear.Tocalltheintroduce()methodfromtheparentclass,usethesuper()methodtoaccessit.Hereishowitlooksincode:classPerson: def__init__(self,name,age): self.name=name self.age=age defintroduce(self): print(f"Hello,mynameis{self.name}.Iam{self.age}yearsold.") #Subclass1. classStudent(Person): def__init__(self,name,age,graduation_year): super().__init__(name,age) self.graduation_year=graduation_year definfo(self): #CallthePersonclassesintroduce()methodtointroducethisStudent. super().introduce() print(f"{self.name}willgraduatein{self.graduation_year}") alice=Student("Alice",30,2023) alice.info()Output:Hello,mynameisAlice.Iam30yearsold. Alicewillgraduatein2023Asyoucansee,nowitispossibletocalltheinfo()methodonaStudentobjecttoseetheintroductionandthegraduationyearprints.Sothesuper()methodcanbeusefulinmanywaysinPython.Thiscompletesourguide.ConclusionTodayyoulearnedwhatthesuper()methoddoesinPython.Torecap,thesuper()methodlinksaparentclasstoitschildclass.Youcanaccessallthepropertiesintheparentclassviathesuper()method.Thanksforreading.Happycoding!FurtherReading50PythonInterviewQuestionsTools&ResourcesforSoftwareDevelopersUsethesewonderfultoolstoincreasemotivation,productivity,andonlinesecurity.ReadMoreShareShareontwitterShareonlinkedinShareonfacebookShareonpinterestShareonemailartturijalliHi,I'mArtturi! 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