Python06:for循环

初识for循环：

#!/usr/bin/env python
# -*- coding:utf-8 -*-
#Author:Mclind

for i in range(10):
    print ("loop", i)

输出：

loop 0

loop 1

loop 2

loop 3

loop 4

loop 5

loop 6

loop 7

loop 8

loop 9

Process finished with exit code 0

解释：

range(10)：就相当于产生10个数字（0、1、2、3、4、5、6、7、8、9）

猜数字用for循环实现：

#!/usr/bin/env python
# -*- coding:utf-8 -*-
#Author:Mclind

age = 56

for i in range(3):
    guess_age = int(input("guess age:"))
    if guess_age == age:
        print("yes, you got it.")
        break
    elif guess_age > age:
        print("think smaller...")
    else:
        print("think bigger...")
else:
    print("you have tried too many times... fuck off")

结果略，同while产生同样的效果，也可以接else，同while一样。

for循环打印（设置步长）：

#!/usr/bin/env python
# -*- coding:utf-8 -*-
#Author:Mclind

for i in range(0,10,1):
    print("lo

输出结果：

loop 0

loop 1

loop 2

loop 3

loop 4

loop 5

loop 6

loop 7

loop 8

loop 9

Process finished with exit code 0

for循环打印（设置步长）：

#!/usr/bin/env python
# -*- coding:utf-8 -*-
#Author:Mclind

for i in range(0,10,2):
    print("loop", i)

输出结果：

loop 0

loop 2

loop 4

loop 6

loop 8

Process finished with exit code 0

for循环打印（设置步长）：

#!/usr/bin/env python
# -*- coding:utf-8 -*-
#Author:Mclind

for i in range(0,10,3):
    print("loop", i)

输出结果：

loop 0

loop 3

loop 6

loop 9

Process finished with exit code 0

解释：

range（x,y,z）：x：起始值；

             y：终止值；

             z：步长。结合程序理解。