Day1：循环语句（While，For）

一、while循环

　　while 条件：

　　　　条件为真执行的语句

　　esle:

　　　　条件为假执行的语句

#!/usr/bin/env python

# -*- coding:utf-8 -*-

# Author:Hiuhung Wan

count = 0

while count < 100:

    print("Count:",count)

    count += 1

　　猜年龄升级版

 #!/usr/bin/env python

 # -*- coding:utf-8 -*-

 # Author:Hiuhung Wan

 age_of_MrWang = 48

 count = 0

 while count < 3:

     guess_age = int(input("Enter the age of Mr Wang:"))

     if guess_age == age_of_MrWang:

         print("Yes,you got it!")

         break

     elif guess_age < age_of_MrWang:

         print("Think bigger!")

     else:

         print("Think smaller!")

     count += 1

     # if count == 3:

     #     print("You have tried too many times...Fuck off!")

 else:

     print("You have tried too many times...Fuck off!")

二、For循环

　　for i in range (xx):

　　　　语句

　　else:

　　　　上面循环里的语句正常走完了后，才执行这里的语句

#!/usr/bin/env python

# -*- coding:utf-8 -*-

# Author:Hiuhung Wan

for i in range(10):

    print("loop",i)

　　再次优化一下猜年龄小程序

 #!/usr/bin/env python

 # -*- coding:utf-8 -*-

 # Author:Hiuhung Wan

 age_of_MrWang = 48

 for i in range (3):

     guess_age = int(input("Enter the age of Mr Wang:"))

     if guess_age == age_of_MrWang:

         print("Yes,you got it!")

         break

     elif guess_age < age_of_MrWang:

         print("Think bigger!")

     else:

         print("Think smaller!")

 else:

     print("You have tried too many times...Fuck off!")

三、for循环步长问题

　　range里可以设置，默认是1

#!/usr/bin/env python

# -*- coding:utf-8 -*-

# Author:Hiuhung Wan

for i in range(0,10,2):   #步长是2

    print("loop",i)

四、猜年龄小程序加入继续玩模式

　　思路：猜了三次还没有猜对，提示是否继续猜，如果按n就退出程序，其他键就继续猜。同时判断输入是否为数字

#!/usr/bin/env python

# -*- coding:utf-8 -*-

# Author:Hiuhung Wan

age_of_MrWang = 48

count = 0  #计数器

while count < 3:

    guess_age = input("Enter the age of Mr Wang:")

    if guess_age.isdigit(): #输入了数字

        guess_age = int(guess_age)

        if guess_age == age_of_MrWang:

            print("Yes,you got it!")

            break  #猜对了，退出while循环

        elif guess_age < age_of_MrWang:

            print("Think bigger!")

        else:

            print("Think smaller!")

        count += 1

        if count == 3:

            continue_confirm = input("Do you want to keey guessing?")

            if continue_confirm != "n":

                count = 0  # 计数器清零

    else:

        print("Please enter a number!")

五、break与continue

　　continue:跳出本次循环（或者说：结束当前循环），继续下一次循环

　　break:结束整个循环

#!/usr/bin/env python

# -*- coding:utf-8 -*-

# Author:Hiuhung Wan

for i in range(0,10):

    if i < 5:

        print("loop",i)

    else:

        continue

    print("The variable i loops once")

六、for循环嵌套

　　注意break的使用

#!/usr/bin/env python

# -*- coding:utf-8 -*-

# Author:Hiuhung Wan

for i in range(10):

    print("-------",i)

    for j in range (10):

        print(j)

        if j > 5:

            break  #结束当前循环（j），继续下一次循环

巴特西