If嵌套

# 一个随机数程序
import random
rand = random.randint(0,10)
var =input('please input a numer\n>')
var = int(var)
if var > 0:
    print('This is a postive')
    if ( var >= 18 ) and ( var <= 60 ):
        print('You are at normal age')
    elif ( var < 18 ):
        print('You are too young to work!')
    else:
        print('You should retire')
elif var < 0:
    print('This is a nagetive')
else:
    print('This is zero')

在C语言中

else if被简化为 elif

只要对其，就不需要大括号

但是语句一行的末尾需要引号标识

需要借助IDE来区分逻辑关系

三目运算符

a = a if a > b else b

Python中诊治放在前面，否值放在后面