Python notes (ix)

1 #Encoding=utf-82 3 #Python Advanced Programming4 5     #Python Object-oriented6         #Create Class7 8 #inadvertently reduced Visual Studio Code window, checked, you can use the ctrl+= magnification window, using ctrl+-Zoom out window9 Ten  One  A classPerson:#the declaration of the class here uses class -     'The baseclass of Human'                    #document string, equivalent to the description of the class -Ins_count=0#What is stated here is the class variable, which is common in all instantiated objects, similar to what we call static variables the    -     def __init__(self,name,age,sex):#the declaration of the method here is to initialize the constructor with def,__init__ (), noting that the init here is double-underlined -Self.name=name#the declaration of a class variable, similar to our property, is accessed only in the current instantiated object -Self.age= Age +self.sex=Sex -Self.ins_count+=1 +  A     defLoginfo (self):#The definition of the method, which uses similar person.loginfo (), is a wrong way to call at         if(self.sex==1):#Self represents an instance of a class, which is necessary when you define a method of a class, but you do not have to pass in the appropriate arguments when calling -             Print 'His name is', Self.name,', age is', Self.age -         Else: -             Print 'Her name is', Self.name,', age is', Self.age#by the symbol "." To implement access to a property -         PrintSelf.ins_count -      in     defLogage (self):#Common Methods -         Print ' Age is', Self.age to  + @staticmethod -     defPrintclassname ():#static methods cannot access class and instance properties the         Print ' Person' *  $ @classmethodPanax Notoginseng     defPrintattr (CLS):#class methods can access class properties cannot access instance properties -         PrintCls.ins_count the      +     def __del__(self): A         Print 'Drop' the  +P=person ('Hanmeimei', 13,0)#Use the person () Form to create an instance of the class, without having to instantiate it with new as in other object-oriented languages - Person.printclassname () $ P.loginfo () $  -  - Print(GetAttr (P,'name')) the  - 'built-in properties of the Python class: __dict__, Class properties (including a dictionary consisting of the class's property data)'Wuyi PrintPerson.__dict__ #data properties of the output class the PrintPerson.__name__ #Output Class name - PrintPerson.__module__ #the module where the output class resides Wu PrintPerson.__doc__ #document string for output class - PrintPerson.__bases__ #the constituent tuples of all the parents of the output class About  $ #del P # When the object is created, a reference is created, and when the object is not needed, the interpreter will reclaim the memory space occupied by the garbage object at the appropriate time and define the __DEL__ function to be called when the object is destroyed -  - classStudent (person):#The left is the class's inheritance, using Class child (parent) -     __serialno=10086#declare private variables that are not accessible externally A     defLogage (self):#if the method of the parent class does not meet the requirements, you can override the parent class's methods in the child class +         if(self.sex==1):                        the             Print ' He is', Self.age -         Else: $             Print ' She is', Self.age the  the     def __addserialno(self):#define private methods that cannot be accessed externally theSelf.__serialno+=1 the  - #a description of the underscore, such as __foo () __ This is a special method of the head and tail of the double underline, generally represents the system-defined name, such as __init () __, _foo () The beginning of a single underline this is the protected level, __foo () A double underscore starts with the private level in  the  theS=student ('Lilei', 15,1) About S.loginfo () the s.logage () the  the #familiar with the object-oriented comrades may find there is no overloading, the author said yes, I do not, and my idea does not match, ...

Python notes (ix)