python基础学习3_if_for

if用于条件判断，如果满足条件就执行否则就继续直到结束，熟悉shell条件判断就觉得so easy

格式：

if condition1:

execute command

elif condition2:

execute command

else:

execute command

for n in condition:

execute command

if示例1：     #基于windows版 python3.5

#!/usr/bin/env pyhon# -*- coding: UTF-8 -*-# authors: jack

age = 28guess_num = int(input("INPUT YOUR GUESS NUM:"))if guess_num == age:    print("Your guess right.GOOD!!!")elif guess_num > age:    print("Your guess letter!")else:    print("Your guess smaller!")

if示例2：

#!/usr/bin/env pyhon# -*- coding: UTF-8 -*-# authors: jack

user = ‘jack‘passwd = ‘jack123‘

username = input("username:")password = input("password:")

if user == username and password == passwd:    print ("username is correct...,login success!!!")else:     print("Invaild username or password error...")

for示例1：#!/usr/bin/env pyhon# -*- coding: UTF-8 -*-# authors: jack

age = 28for n in range(10):    if n < 3:        guess_num = int(input("INPUT YOUR GUESS NUM:"))        if guess_num == age:            print("Your guess right.GOOD!!!")            break              #跳出整个loop        elif guess_num > age:            print("Your guess letter!")        else:            print("Your guess smaller!")    else:        print("too many attempts ...bye bye")        break