在for循环外指定变量

I have the following for loop written to sum all numbers in a list. I'm aware there is a sum function in python.

我有以下for循环写入来汇总列表中的所有数字。我知道python中有一个sum函数。

tot = 0
var = 5
for num in range(1, var + 1):
    tot += num
print tot    

When I try to intialise tot within the for loop, it gives an incorrect answer: i.e.

当我尝试在for循环中初始化时,它给出了一个错误的答案:即

var = 5
for num in range(1, var + 1):
    tot = 0
    tot += num
print tot  

Any reason for this? Please note, I'm a beginner in python.

有什么理由吗?请注意,我是python的初学者。

1 个解决方案

#1

In the loop, you reassign the value of tot to zero. Thus, tot will simply be var in the last iteration.

在循环中,您将tot的值重新指定为零。因此,tot将在上一次迭代中简单地为var。