is_vs_equal_equal.py

#! /usr/bin/python3

class x:

    def __init__(self,data):
        self.data = data


# -----------------------------------------------------

def test():

    print('a = {}'.format(a))
    print('b = {}'.format(b))
    print('c = {}'.format(c))

    if a == b:
        print('a == b')
    else:
        print('a != b')

    if a is b:
        print('a is b')
    else:
        print('a is not b')

    if a == c:
        print('a == c')
    else:
        print('a != c')

    if a is c:
        print('a is c')
    else:
        print('a is not c')


a = x(123)
b = a
c = x(123)

test()