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 = 28
guess_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 = 28
for 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