Python——while、break、continue、else

1.while循环语句：

 count = 0
while count <= 100:
     print("loop ", count)
     count += 1
print('----loop is ended----')

2.打印偶数：

# 打印偶数
# count = 0
#
# while count <= 100:
#
#     if count % 2 == 0: #偶数
#         print("loop ", count)
#
#     count += 1
#
#
# print('----loop is ended----')

3.第50次不打印，第60-80打印对应值 的平方

count = 0

while count <= 100:

    if count == 50:
        pass #就是过。。

    elif count >= 60 and count <= 80:
        print(count*count)

    else:
        print('loop ', count)
    
       count+=1

4.死循环

count = 0

while True:
    print("forever 21 ",count)
    count += 1

5.循环终止语句：break&continue

break：用于完全结束一个循环，跳出循环体执行循环后面的语句

continue:不会跳出整个循环，终止本次循环，接着执行下次循环，break终止整个循环

# break 循环
# count=0
# while count<=100:
#     print('loop',count)
#     if count==5:
#         break
#     count+=1
# print('-----out of while loop---')

#continue 循环
count=0
while count<=100:
    print('loop',count)
    if count==5:
        continue
    count+=1
# print('-----out of while loop---')   #一直打印5
#continue 跳出本次循环，不会执行count+=1，count一直为5

例1：让用户猜年龄

age = 26
user_guess = int(input("your guess:"))
if user_guess == age :
    print("恭喜你答对了，可以抱得傻姑娘回家！")
elif user_guess < age :
    print("try bigger")
else :
    print("try smaller")

例2：用户猜年龄升级版，让用户猜年龄，最多猜3次，中间猜对退出循环

count = 0
age = 26

while count < 3:

    user_guess = int(input("your guess:"))
    if user_guess == age :
        print("恭喜你答对了，可以抱得傻姑娘回家！")
        break
    elif user_guess < age :
        print("try bigger")
    else :
        print("try smaller")

    count += 1

例3：用户猜年龄继续升级，让用户猜年龄，猜3次，如果用户3次都错，询问用户是否还想玩，如果为y,则继续猜3次，以此往复【注解提示：相当于在count=3的时候询问用户，如果还想玩，等于把count变为0再从头跑一遍】

count = 0
age = 26

while count < 3:

    user_guess = int(input("your guess:"))
    if user_guess == age :
        print("恭喜你答对了，可以抱得傻姑娘回家！")
        break
    elif user_guess < age :
        print("try bigger")
    else :
        print("try smaller")

    count += 1

    if count == 3:
        choice = input("你个笨蛋，没猜对，还想继续么?(y|Y)")
        if choice == 'y' or choice == 'Y':
            count = 0

6.while&else：while 后面的else的作用是，当while循环正常执行完，中间没有被break中止的话，就会执行else后的语句【else 检测你的循环过程有没有中止过（当你的循环代码比较长的时候）】

 count=0
# while count <=5:
#     count+=1
#     print('loop',count)
#
# else:
#     print('循环正常执行完啦')
# print('-----out of while loop----')

count=0
while count<=5:
    print('loop',count)
    if count==3:
        break
    count+=1
else:
    print('loop is done')