Understanding self and __init__ method in python Class.

"__init__" is a reseved method in python classes. It is known as a constructor in object oriented concepts. This method called when an object is ... 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FirstName* LookingFor* Webdevelopment Mobileappdevelopment Cloudinfrastructureplanningandmanagement Salesforceconsulting Seo CRMdevelopment Company* Website* EmailAddress* ContactNumber* SkypeID* Message* CreateSchedule Understandingselfand__init__methodinpythonClass. Beforeunderstandingthe"self"and"__init__"methodsinpythonclass,it'sveryhelpfulifwehavetheideaofwhatisaclassandobject. Class: Classisasetorcategoryofthingshavingsomepropertyorattributeincommonanddifferentiatedfromothersbykind,type,orquality. Intechnicaltermswecansaythatclassisablueprintforindividualobjectswithexactbehaviour. Object: objectisoneofinstancesoftheclass.whichcanperformthefunctionalitieswhicharedefinedintheclass. self: selfrepresentstheinstanceoftheclass.Byusingthe"self"keywordwecanaccesstheattributesandmethodsoftheclassinpython. __init__: "__init__"isaresevedmethodinpythonclasses.Itisknownasaconstructorinobjectorientedconcepts.Thismethodcalledwhenanobjectiscreatedfromtheclassanditallowtheclasstoinitializetheattributesofaclass. Howcanweuse "__init__"? Let'sconsiderthatyouarecreatingaNFSgame.forthatweshouldhaveacar.Carcanhaveattributeslike"color","company","speed_limit"etc.andmethodslike"change_gear","start","accelarate","move"etc. classCar(object): """ blueprintforcar """ def__init__(self,model,color,company,speed_limit): self.color=color self.company=company self.speed_limit=speed_limit self.model=model defstart(self): print("started") defstop(self): print("stopped") defaccelarate(self): print("accelarating...") "accelaratorfunctionalityhere" defchange_gear(self,gear_type): print("gearchanged") "gearrelatedfunctionalityhere" Letstrytocreatedifferenttypesofcars maruthi_suzuki=Car("ertiga","black","suzuki",60) audi=Car("A6","red","audi",80) Wehavecreatedtwodifferenttypesofcarobjectswiththesameclass.whilecreatingthecarobjectwepassedarguments "ertiga","black","suzuki",60 theseargumentswillpassto"__init__"method toinitializetheobject.  Here,themagickeyword"self" representstheinstanceoftheclass.Itbindstheattributeswiththegivenarguments. Usageof"self"inclasstoaccessthemethodsandattributes Case:Findoutthecostofarectangularfieldwithbreadth(b=120),length(l=160).Itcostsx(2000) rupeesper1squareunit classRectangle: def__init__(self,length,breadth,unit_cost=0):  self.length=length  self.breadth=breadth  self.unit_cost=unit_cost    defget_perimeter(self):  return2*(self.length+self.breadth)    defget_area(self):  returnself.length*self.breadth    defcalculate_cost(self):  area=self.get_area()  returnarea*self.unit_cost #breadth=120cm,length=160cm,1cm^2=Rs2000 r=Rectangle(160,120,2000) print("AreaofRectangle:%scm^2"%(r.get_area())) print("Costofrectangularfield:Rs.%s"%(r.calculate_cost())) Aswealreadydiscussed "self"representsthesameobjectorinstanceoftheclass.Ifyousee,insidethemethod"get_area" wehaveused"self.length" togetthevalueoftheattribute"length".  attribute"length"isbindtotheobject(instanceoftheclass)atthetimeofobjectcreation."self" representstheobjectinsidetheclass."self"worksjustlike"r" inthestatement "r=Rectangle(160,120,2000)". Ifyouseethemethodstructure"defget_area(self):" wehaveused"self" asaparameterinthemethodbecausewheneverwecallthemethod theobject(instanceofclass)automaticallypassesasafirstargumentalongwithotherargumetsofthemethod.Ifnootherargumentsareprovidedonly"self"ispassedtothemethod.That'sthereasonweuse"self"tocallthemethodinsidetheclass("self.get_area()"). weuseobject(instanceofclass)tocallthemethodoutsideoftheclassdefinition("r.get_area()")."r" istheinstanceoftheclass,whenwecallmethod "r.get_area()"  theinstance"r" ispassedasasfirstargumentintheplaceofself.   r=Rectangle(160,120,2000) Note:"r"istherepresentationoftheobjectoutsideoftheclassand"self"  istherepresentationoftheobjectinside theclass. formoredetailspleasevisitpythondocumentation ToKnowmoreaboutourDjangoCRM(CustomerRelationshipManagement)OpenSourcePackage.CheckCode PostedOn05May2017ByMicroPyramid Previouspost Nextpost AboutMicropyramid Micropyramidisasoftwaredevelopmentandcloudconsultingpartnerforenterprisebusinessesacrosstheworld.Weworkonpython,Django,Salesforce,Angular,Reactjs,ReactNative,MySQL,PostgreSQL,Docker,Linux,Ansible,git,amazonwebservices.WeareAmazonandsalesforceconsultingpartnerwith5yearsofcloudarchitectexperience.Wedevelope-commerce,retail,banking,machinelearning,CMS,CRMwebandmobileapplications. 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