Python class instantiation, do not add parentheses after the name of the class is what mean?-CodePudding

For example: the following code

 
# Instantiate FTP handler class 
Handler=FTPHandler 
Handler. The authorizer=authorizer

Not should add parentheses after FTPHandler?

CodePudding user response:

For example you see which is instantiated:

 class clsTest () : 
Y='
Def __init__ (self) : 
The self. The y='you' 

X=clsTest 
Print (x.y) 

X=clsTest () 
Print (x.y)

CodePudding user response:

reference 1st floor chuifengde response:

, for example, you see which is instantiated:

 class clsTest () : 
Y='
Def __init__ (self) : 
The self. The y='you' 

X=clsTest 
Print (x.y) 

X=clsTest () 
Print (x.y)

Add parentheses is class instantiation, what on earth is that do not add parentheses, like I suggested that code, don't understand what you mean

CodePudding user response:

Do not add parentheses is not restart the instance, this should be set an alias is the same as
Handler. The authorizer is actually FTPHandler sharing members of a class

CodePudding user response:

refer to the second floor HowieZhao response:

Quote: refer to 1st floor chuifengde response:

For example you see which is instantiated:

class clsTest () :
Y='
Def __init__ (self) :
The self. The y='you'

X=clsTest
Print (x.y)

X=clsTest ()
Print (x.y)

Add parentheses is class instantiation, what on earth is that do not add parentheses, like I put the code and I don't know what do you mean

To put it bluntly bracketing is calling the init function without parentheses is not call the init function

CodePudding user response:

You can print out the two instantiate type, do not add parentheses is equivalent to set an alias, its type should be & lt; The type 'classobj & gt;; But add parentheses is the right way to instantiate, printing type should be & lt; The type 'instance & gt;

CodePudding user response:

Personally, I think python is a reference mechanism, do not add parentheses rather then a variable pointing to the class in the space, there are brackets are to perform

CodePudding user response:

 
The class clsTest () : 
Y='
Def __init__ (self) : 
The self. The y='you'

> Type (b)
> C=clsTest ()
> Type (c)

The above code, is a class b,
B.a uthorizer=authorizer
In fact is for class attr assignment,

CodePudding user response:

Unable to edit out a reply,,,,,,,
-- -- -- -- -- -- -- -- -- --

 
The class clsTest () : 
Y='
Def __init__ (self) : 
The self. The y='you'

> B=clsTest
> Type (b)
> C=clsTest ()
> Type (c)
& lt; The class '__main__. ClsTest & gt;

The above code, is a class b,
B.a uthorizer=authorizer
In fact is for class attr assignment,

CodePudding user response:

Python everything object, class itself is object, do not add parentheses is object reference

CodePudding user response:

In short, do not add parentheses is assignment,
1st floor of the case, call x and call clsTest is the same,

CodePudding user response:

Add parentheses is instantiated, init magic methods will call after listening to instantiate, do not add parentheses, is called the class itself,