I have a list of lists of tuples. Each inner list contains 3 tuples, of 2 elements each:

```
[
[(3, 5), (4, 5), (4, 5)],
[(7, 13), (9, 13), (10, 13)],
[(5, 7), (6, 7), (7, 7)]
]
```

I need to get a single list of 3 tuples, summing all these elements "vertically", like this:

```
(3, 5), (4, 5), (4, 5)
+ + + + + +
(7, 13), (9, 13), (10, 13)
+ + + + + +
(5, 7), (6, 7), (7, 7)
|| || ||
[(15, 25), (19, 25), (21, 25)]
```

so, for example, the second tuple in the result list is given by the sums of the second tuples in the initial list

(4+9+6, 5+13+7) = (19, 25)

I’m trying with list/tuple comprehensions, but I’m getting a little lost with this.

### >Solution :

You could do this pretty easily with numpy. Use sum on axis 0.

```
import numpy as np
l = [
[(3, 5), (4, 5), (4, 5)],
[(7, 13), (9, 13), (10, 13)],
[(5, 7), (6, 7), (7, 7)]
]
[tuple(x) for x in np.sum(l,0)]
```

Output

```
[(15, 25), (19, 25), (21, 25)]
```