python issubclass and isinstance functions

Python issubclass () Function

issubclass()  Method is used to determine parameters  class  Is it a type parameter  classinfo  Gets or sets a subclass of. 

 Syntax: 

issubclass(class, classinfo)

 Parameter 

class --  Class. 
classinfo --  Class. 

 Return value 

 If  class  Yes  classinfo  Returns a subclass of  True Otherwise, return  False . 

 Examples: 

#!/usr/bin/python
# -*- coding: UTF-8 -*-
class A:
  pass
class B(A):
  pass
print(issubclass(B,A))  #  Return  True

Python isinstance () Function

isinstance()  Function to judge 1 Is the object 1 A known type, similar to  type() . 
isinstance()  And  type()  Difference: 

type()  Does not consider a subclass to be 1 Species parent class type, regardless of inheritance relationship. 

isinstance()  Will think that subclasses are 1 Species parent class type, considering inheritance relationship. 

 If you want to determine whether two types are the same, it is recommended to use  isinstance() . 

 Syntax: 

isinstance(object, classinfo)

 Parameter 

object --  Instance object. 
classinfo --  It can be a direct or indirect class name, a base type, or a tuple composed of them. 

 Return value 

 If the type and parameters of the object 2 The type of the ( classinfo ) Is the same  True Otherwise, return  False . 

 Examples: 

>>>a = 2
>>> isinstance (a,int)
True
>>> isinstance (a,str)
False
>>> isinstance (a,(str,int,list))  #  Is in the tuple 1 Return  True
True

type()  And  isinstance() Difference: 

class A:  pass
class B(A):
  pass
isinstance(A(), A)  # returns True
type(A()) == A    # returns True
isinstance(B(), A)  # returns True
type(B()) == A    # returns False

Summarize