inheritance.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
from __future__ import print_function
import sys

class A(object):
    """
    Base Class
    """
    def __init__(self):
        self._dict = {}
        self._count = 0
        print("self._dict = " + str(self._dict))
        print("self._count = " + str(self._count))
        self.__add_by_a()

    def __add_by_a(self):
        if len(self._dict) == 0:
            print("add pair by A")
            self._dict["key_a"] = "value_a"
        else:
            sys.exit("error: _dict not empty")

        if self._count == 0:
            print("count plus 1 by A")
            self._count += 1
        else:
            sys.exit("error: _count not empty")

class B(A):
    """
    Sub Class B
    """

    def __init__(self):
        super(B, self).__init__()
        self.__add_by_b()
        print(self._dict)
        print(self._count)
    
    def __add_by_b(self):
        print("add pair by B")
        self._dict["key_b"] = "value_b"
        print("count plus 1 by B")
        self._count += 1

class C(A):
    """
    Sub Class C
    """

    def __init__(self):
        super(C, self).__init__()
        self.__add_by_c()
        print(self._dict)

    def __initializing(self):
        self.__add_by_c()

    def __add_by_c(self):
        print("add pair by C")
        self._dict["key_c"] = "value_c"
        print("count plus 1 by C")
        self._count += 1
                
def main():
    obj_B = B()
    print("-----")
    obj_C = C()

if __name__ == '__main__':
    main()