Python defines class learning 1

此时的d1就是类Dog的实例化对象

实例化，其实就是以Dog类为模版，在内存里开辟一块空间，存上数据，赋值成一个变量名

#Defining class TemplatesclassDog (object):#defining method functions for a class    #speech function Self must have    defSayhi (self):Print("helo")#instantiating an object through a classD1 = Dog ("Xiao Tao")Print(D1)#<__main__.dog object at 0x0000000001ecd208>#invoking a method in a class through an objectD1.sayhi ()#helo

#Defining class TemplatesclassDog (object):#defining the properties of a class    def __init__(self, name):#equivalent to creating a variable NAMESelf.name =name#defining method functions for a class    #speech function Self must have    defSayhi (self):Print("helo")#instantiating an object through a classD1 = Dog ("Xiao Tao") D2= Dog ("Xiao Feng")Print(D1)#<__main__.dog object at 0x0000000001ecd208>#invoking a method in a class through an objectD1.sayhi () d2.sayhi ( )#helo

The characteristic local variables of a function that is spelled out by multiple functions are also

With self it is possible to call the local variables between functions, various string formatting formats

#Defining class TemplatesclassDog (object):#defining the properties of a class                #D1    def __init__(self, name):#equivalent to creating a variable NAMESelf.name =name#d1.name =name    #defining method functions for a class    #speech function Self must have    defSayhi (self):Print("helo, i m is {name}". Format (name=self.name)) Print("helo, i m is {0}". Format (self.name))Print("helo, i m is%s"%self.name)Print("helo, i m is", Self.name)#instantiating an object through a class D1 D2D1 = Dog ("Xiao Tao")#Dog (D1, "Xiao Tao") Pass parametersD2 = Dog ("Xiao Feng")Print(D1)#<__main__.dog object at 0x0000000001ecd208>#invoking a method in a class through an objectD1.sayhi () d2.sayhi ( )#helo, i m is Xiao Tao#helo, i m is Xiao Feng

No instantiation of the print class proves that the class already exists in memory after the class is created

#Defining class TemplatesclassDog (object):#defining the properties of a class                #D1    def __init__(self, name):#equivalent to creating a variable NAMESelf.name =name#d1.name =name    #defining method functions for a class    #speech function Self must have    defSayhi (self):Print("helo, i m is {name}". Format (name=self.name)) Print("helo, i m is {0}". Format (self.name))Print("helo, i m is%s"%self.name)Print("helo, i m is", Self.name)#instantiating an object through a class D1 D2#D1 = Dog ("Little Tao") # Dog (D1, "Little Tao") Pass parameters#D2 = Dog ("Xiao Feng")#print (D1)### <__main__.dog Object at 0x0000000001ecd208>### Invoke the method in the class through the object#D1.sayhi ()##D2.sayhi ()#helo, i m is Xiao Tao#helo, i m is Xiao FengPrint(dog)#Execution Results<class '__main__.dog'>

The object generated after instantiation is called an instance.  D1, D2 is an example, self  is an instance

__init__ is the method by which constructor constructor method functions are classes.

#Defining class TemplatesclassDog (object):#defining the properties of a class                #D1    #Self is an instance .    def __init__(self, name):#Constructor constructor Method = = Initialization Method        #equivalent to creating a variable NAMESelf.name =name#d1.name =name    #defining method functions for a class    #speech function Self must have    defSayhi (self):#methods of the class        Print("helo, i m is {name}". Format (name=self.name)) Print("helo, i m is {0}". Format (self.name))Print("helo, i m is%s"%self.name)Print("helo, i m is", Self.name)#instantiating an object through a class D1 D2D1 = Dog ("Xiao Tao")#Dog (D1, "Xiao Tao") Pass parametersD2 = Dog ("Xiao Feng")#an instance of an object called an instance D2 is an instance.

#Defining class TemplatesclassDog (object):#defining the properties of a class                #D1    #Self is an instance .    def __init__(self, name):#Constructor constructor Method = = Initialization Method        #equivalent to creating a variable NAMESelf.name =name#d1.name =name    #defining method functions for a class    #speech function Self must have    defSayhi (self):#methods of the class        Print("helo, i m is {name}". Format (name=self.name)) defEat (Self,food):Print("helo, my name is%s, I like eat%s"%(Self.name,food))#instantiating an object through a class D1 D2D1 = Dog ("Xiao Tao")#Dog (D1, "Xiao Tao") Pass parametersD2 = Dog ("Xiao Feng")#an instance of an object called an instance D2 is an instance.D1.eat ("Apple")#helo, my name is Xiao Tao, I like eat apple

Python defines class learning 1