this question is less about a specific issue, and more about a problem that I continuously have while working with arrays.

Say I have an array like this:

```
x = [4,7,11]
```

If I wanted to add al of these together, what I would do is:

```
for i in range(len(x)-1):
x[i+1] = x[i]+x[i+1]
x[i] = 0
```

I would then follow this with:

```
for i in x:
if i == 0:
x.remove(i)
```

Although this works, It’s incredibly slow and definitely not the most efficient way to do this, besides taking up several extra lines.

If anyone has a better way to do this, please tell me. This physically hurts me every time I do it.

### >Solution :

As TYZ said, you can simply use `sum(x)`

for getting the sum of a numerical list.

For subtraction where you subtract later items from the first item, you can use `x[0]-sum(x[1:])`

.