循环语句--for

1、guess_age优化版v1.py

 #coding=utf-8
 age = 22

 for i in range(10):
     if i < 3:
         guess_num = int(input('input your guess num:'))
         if guess_num == age:
             print ('Congratulations！you got it.')
             break   #不往后走了，跳出整个loop
         elif guess_num > age:
             print ('Think smaller!')
         else:
             print ('Think big...')
     else:
         print ('Try too many times...')
         break

2、guess_age优化版v1.py

 #coding=utf-8
 age = 22

 for i in range(10):
     print ('loop_i:',i)
     if i < 3:
         guess_num = int(input('input your guess num:'))
         if guess_num == age:
             print ('Congratulations！you got it.')
             break   #不往后走了，跳出整个loop
         elif guess_num > age:
             print ('Think smaller!')
         else:
             print ('Think big...')
     else:
         continue_confirm = input('Do you want to continue because you are stupid:')
         if continue_confirm == 'y':
             '''这个地方i虽然被重新赋值了，但是从下面的结果来看（标红的），
             等到返回for循环的时候因为range的值此时是4，又把i给重新赋值了，
             所以看到的是loop_i=4而不是loop_i=0，从这里我们可以看出每次的循环是in后面的序列给i赋值的'''
             i = 0
             print ('new i:',i)
         else:
             print('bye')
             break

测试结果：

loop_i: 0

input your guess num:1

Think big...

loop_i: 1

input your guess num:1

Think big...

loop_i: 2

input your guess num:1

Think big...

loop_i: 3

Do you want to continue because you are stupid:y

new i: 0

loop_i: 4

Do you want to continue because you are stupid:y

new i: 0

loop_i: 5

Do you want to continue because you are stupid:

 

guess_age优化版v1.py这个程序并没有实现想要的结果，继续优化

 

3、guess_age优化版v3.py

 #coding=utf-8

 age = 22
 counter = 0
 for i in range(10):
     print ('counter:',counter)
     if counter < 3:
         guess_num = int(input('input your guess num:'))
         if guess_num == age:
             print ('Congratulations！you got it.')
             break   #不往后走了，跳出整个loop
         elif guess_num > age:
             print ('Think smaller!')
         else:
             print ('Think big...')
     else:
         continue_confirm = input('Do you want to continue because you are stupid:')
         if continue_confirm == 'y':
             counter = 0
             continue  #跳出当次循环
         else:
             print('bye')
             break
     counter += 1

结果：

counter: 0

input your guess num:1

Think big...

counter: 1

input your guess num:1

Think big...

counter: 2

input your guess num:1

Think big...

counter: 3

Do you want to continue because you are stupid:y

counter: 0

input your guess num:1

Think big...

counter: 1

input your guess num:1

Think big...

counter: 2

input your guess num:1

Think big...

counter: 3

Do you want to continue because you are stupid:y

counter: 0

input your guess num:1

Think big...

counter: 1

input your guess num:1

Think big...