Python范围问题

Question

我正在编写一个程序,在这个程序中需要确定数字的范围,好像我在user_input'a'中放了15,所以它应该打印范围从'a'到'b'但不幸的是我无法解决它的问题有人请帮帮我.这是我的代码:

a = int(raw_input("How many did you say you're going to count down? "))
b = int(raw_input("When are you actually going to stop? "))
i = 0
for i in range(a, b):
    i = i + 1
    print i 

我希望它像这样工作:

How many did you say you're going to count down? 15
When are you actually going to stop? 8
15
14
13
12
11
10
9
8

要么

How many did you say you're going to count down? 6
When are you actually going to stop? 4
6
5
4

Answer 1

循环可以是:

a = int(raw_input("How many did you say you're going to count down? "))
b = int(raw_input("When are you actually going to stop? "))

for i in range(a, b-1, -1):
    print i 

(假设计数减少).

你必须知道的是:

1. 该for环路为你做递减(不需要i = i-1用C等).
2. range(a, b-1, -1)是一个列表(在Python 2中),从步骤a到b-1(不包括)-1.例如,您可以尝试在Python shell中执行此操作print range(10, 5, -1).您还可以检查输出range(5, 11, 2),以更好地了解range()它的作用.