表达式if ... else
一、用户登陆验证
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# 提示输入用户名和密码 # 验证用户名和密码# 如果错误，则输出用户名或密码错误# 如果成功，则输出 欢迎，XXX!#!/usr/bin/env python# -*- coding: encoding -*- _password = ‘zxc123‘
username = input("username:")
password = input("password:")
if _username == username and _password == password:
print("Welcome user {name} login...".format(name=username))
else:
print("Invalid username or password!")
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二、猜年龄游戏
在程序里设定好你的年龄，然后启动程序让用户猜测，用户输入后，根据他的输入提示用户输入的是否正确，如果错误，提示是猜大了还是小了,
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#!/usr/bin/env python# -*- coding: utf-8 -*-my_age = 26
guess_age = int(input("guess age:") )
if guess_age == my_age :
print("yes, you got it. ")
elif guess_age > my_age:
print("think smaller...")
else:
print("think bigger!")
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二、while loop
有一种循环叫死循环
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count = 0while True: print("死循环",count) count +=1 |
上面猜年龄用while 循环去实现： 只猜3次
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#!/usr/bin/env python# -*- coding: utf-8 -*-count = 0
my_age = 26
while count < 3:
guess_age = int(input("guess age:") )
if guess_age == my_age :
print("yes, you got it. ")
break
elif guess_age > my_age:
print("think smaller...")
else:
print("think bigger!")
count +=1
else:
print("you have tried too many times..fuck off")
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三、表达式for loop
最简单的循环5次
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#_*_coding:utf-8_*___author__ = ‘Many Qian‘for i in range(5): print("loop:", i ) |
输出：
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loop: 0loop: 1loop: 2loop: 3loop: 4 |
需求一：还是上面的程序，但是遇到小于5的循环次数就不走了，直接跳入下一次循环
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for i in range(10): if i<5: continue #不往下走了,直接进入下一次loop print("loop:", i ) |
需求二：还是上面的程序，但是遇到大于5的循环次数就不走了，直接退出
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for i in range(10): if i>5: break #不往下走了,直接跳出整个loop print("loop:", i ) |
用上面学的for循环做猜年龄：
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#!/usr/bin/env python# -*- coding: utf-8 -*-my_age = 26
for i in range(3):
guess_age = int(input("guess age:") )
if guess_age == my_age :
print("yes, you got it. ")
break
elif guess_age > my_age:
print("think smaller...")
else:
print("think bigger!")
else:
print("you have tried too many times..fuck off")
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