__str__ is called by the print function to print the contents of the class to the screen

#-*-coding:utf-8-*-#python#Xiaodeng#__str__ is called by the print function to print the contents of the class to the screenclassapierror ():def __init__(self, Error_code, request): Self.error_code=Error_code self.request=Requestdef __str__(self):#It's usually return .        return 'apierror:%s, \nrequest:%s'%(Self.error_code, self.request)#Error=apierror (' -','This is a error')PrintErrorPrinttype (Error)#__str__ is basically consistent with the STR function, except that STR is used in simple strings, and __str__ is usually used in classes, and when printing a class, print first calls the __str__ defined in the class." "apierror:100, Request:this is a error<type ' instance ' >" "

__str__ is called by the print function to print the contents of the class to the screen