Python2 Learning------Basic Syntax 2 (classes, class inheritance, class member functions, defensive programming)

1. Definition of class and instantiation

#class definitionclassP:"""This is a basic class"""    def __init__(self):#The class member function needs to pass in the Self keyword        """This is a init function of basic class"""        Print "This is a init function ..."; defSub (SELF,A,B):#The class member function needs to pass in the Self keyword        """This is a common function of basic class"""        returnA-b;#class instantiationA=p ();#Calling class methodsPrintA.sub (40,5);#-1

2. Inheritance of Classes

#Inheriting ClassesclassM (p):#parameter is the name of the class that needs to be inherited    """This is a sub-class of basic class"""    def __init__(self):#proprietary functions (with double underscores for function names)        Print "Sub class init function ..."; Self.__test(); defLoopoutputfun (self,n):ifn<0:PrintN"is not a postive integer"Retrun;  forIinchRange (1,n,3):            Printi; Else:            Print "loop output over ..."; def __test(self):#private Functions (the first part of the function has a double stroke)        Print "the private function of a class cannot be called directly by an instance of the class, but only by a proprietary function call (requires the SELF keyword)"; def __my__(self):#proprietary functions (with double underscores for function names)Self.__test(); defdev__ (self,a,b):"""Demonstrating exceptions"""        Try:            returnA/C; exceptexception,e:PrintE.message; def __passtest__(self):"""when the function logic is not well planned, the PASS keyword is used for processing"""        Pass;#instantiation of Subclassesb=m ();#Calling Subclass MethodsPrintB.sub (100, 55); B.loopoutputfun (10); b.__my__();Printb.dev__ (10,2); b.__passtest__();

3.

Python2 Learning------Basic Syntax 2 (classes, class inheritance, class member functions, defensive programming)