python--if，while，break，continue

python--if，while，break，continue

if

你在生活中是不是经常遇到各种选择，比如玩色子，猜大小，比如走那条路回家。python程序中也会遇到这种情况，这就用到了 if 语句

_username = 'zou'_password = 'abc123'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!")

money = int(input("请输入你兜里的钱:"))if money > 500: print("吃啤酒吃炸鸡. 生活美滋滋")elif money > 300: print("盖浇饭走起")elif money > 50: print("方便面走起")else: print("减肥走起")

while

在生活中，我们遇到过循环的事情吧？比如循环听歌，在程序中，循环也是存在的，

count=0while True: print("count:",count) count=count+1

陷入了死循环，在实际项目中要避免出现死循环，True 的T必须是大写

age_of_oldboy = 56while True: guess_age = int(input('guess age:')) if guess_age == age_of_oldboy: print("yes, you got it. ") elif guess_age > age_of_oldboy: print("think smaller...") else: print("thing bigger...")

一直可以输入，对或错都不结束

age_of_oldboy = 56while True: guess_age = int(input('guess age:')) if guess_age == age_of_oldboy: print("yes, you got it. ") break elif guess_age > age_of_oldboy: print("think smaller...") else: print("thing bigger...")

加了个break，输入正确时退出break 结束循环. 停止当前本层循环

age_of_oldboy = 56count = 0while count < 3: guess_age = int(input('guess age:')) if guess_age == age_of_oldboy: print("yes, you got it. ") break elif guess_age > age_of_oldboy: print("think smaller...") else: print("thing bigger...") count = count + 1

输错三次退出循环

age_of_oldboy = 56count = 0while count < 3: guess_age = int(input('guess age:')) if guess_age == age_of_oldboy: print("yes, you got it. ") break elif guess_age > age_of_oldboy: print("think smaller...") else: print("thing bigger...") count = count + 1else: print("you have tried too many times...")

当程序正常执行完会执行最后一个else，如果中间遇到break，不执行else

while True: s = input("请开始说:") if s == 'q': break # 停止当前循环 # 过滤掉马化腾 if "马化腾" in s: # 在xxx中出现了xx print("你输入的内容非法. 不能输出") continue # 停止当前本次循环.继续执行下一次循环 print("喷的内容是:"

count = 1while count <= 10: print(count) count = count + 1 if count == 5: break # 彻底停止循环. 不会执行后面的elseelse: # while条件不成立的时候执行 print("这里是else")

continue：停止本次循环，继续执行下一次循环

版权声明：本文内容由网络用户投稿，版权归原作者所有，本站不拥有其著作权，亦不承担相应法律责任。如果您发现本站中有涉嫌抄袭或描述失实的内容，请联系我们jiasou666@gmail.com 处理，核实后本网站将在24小时内删除侵权内容。