Python `+=` operator in one single line for list

Question

Now I have a list a = [1,2,3]. How could I get result [1,3,6] only using one line code?

I can achive it like this , but I want use one line code.

k=0 
arr = [] 
a = [1,2,3] 
for i in a: 
    k+=i 
    arr.append(k) 
print(arr)

score 2 · Answer 1 · answered Jun 29 '22 at 08:41

2

a = [1,2,3] 
arr = [sum(a[:i + 1]) for i in range(len(a))] 
print(arr)

answered Jun 29 '22 at 08:41

Ved Rathi

It's N square complxcity . I want only count like += opreater – shuai shuai Jun 29 '22 at 08:44
[How to find the cumulative sum of numbers in a list?](https://stackoverflow.com/a/57724791/6045800) – Tomerikoo Jun 29 '22 at 08:53

score 1 · Answer 2 · answered Jun 29 '22 at 08:43

1

If you really want to do it in one line and efficiently, you can use itertools.accumulate:

In [1]: import itertools

In [2]: a = [1, 2, 3]

In [3]: list(itertools.accumulate(a))
Out[3]: [1, 3, 6]

answered Jun 29 '22 at 08:43

Lev Levitsky

[How to find the cumulative sum of numbers in a list?](https://stackoverflow.com/a/15889203/6045800) – Tomerikoo Jun 29 '22 at 08:53

2 Answers2