习题26：if(如果)

练习代码如下

# coding: utf-8
__author__ = 'www.py3study.com'
people = 20
cats = 30
dogs = 15
if people < cats:
    print("Too many cats! The world is doomed!")
if people > cats:
    print("Not many cats! The world is saved!")
if people < dogs:
    print("The world is drooled on !")
if people > dogs:
    print("The world is dry!")

dogs += 5
if people >= dogs:
    print("People are greater than or equal to dogs.")
if people <= dogs:
    print("People are less than or equal to dogs.")
if people == dogs:
    print("People are dogs.")

应该看到的结果

常见问题

+=是什么意思？

x += 1 和 x = x + 1一样，只是+=这种写法更省时间