Python流程控制之while循环

一、基本使用

count = 2
while count < 4:
    print(count)
    count += 1
print('顶级循环')

二、退出循环的两种方式

1、将条件改为False，下次才结束

username = 'brynn'
userpwd = '123'
tag = True

while tag:
    name = input('your name :')
    pwd = input('your password :')

    if name == username and pwd == userpwd:
        print('success')
        tag=False
    else:
        print('False and input again')
    print('end')

2、break，只要运行到break，就会立即终止本层循环。

username = 'brynn'
userpwd = '123'

while 1:
    name = input('your name :')
    pwd = input('your password :')

    if name == username and pwd == userpwd:
        print('success')
        break
    else:
        print('False and input again')
    print('end')

三、结束本次循环，直接进入下一次：while+continue

count=0
while count<6:
    if count==4:
        count+=1
        continue
    print(count)
    count+=1
# 结果
# 0
# 1
# 2
# 3
# 5

四、while+else

count = 0
while count < 6:
    if count == 4:
        count += 1
        continue
    print(count)
    count += 1
else:
    print('^.^')
# 0
# 1
# 2
# 3
# 5
# ^.^