#!/usr/bin/env python
# -*- coding: utf-8 -*-

class Person:
    # Class attributes
    # the same for everyone.
    number_of_people = 0

    def __init__(self, name):
        self.name = name
        #Person.number_of_people += 1
        Person.add_person()


    @classmethod
    def number_of_people_(cls):
        return cls.number_of_people

    @classmethod
    def add_person(cls):
        cls.number_of_people += 1

p1 = Person('tim')
p2 = Person('jill')
print(p2.number_of_people)
print(Person.number_of_people_())