So in Python NumPy, I have a list of list from 0 to 99 divided by 5:

```
array_b = np.arange(0,100).reshape(5, 20)
list_a = array_b.tolist()

```

I want to add the numbers in the list by column so that the result will be:

```
[200 205 210 215 220 225 230 235 240 245 250 255 260 265 270 275 280 285 290 295]

```

I know how to do it in the array version, but I want to do the same thing in the list version (without using np.sum(array\_b, axis=0)).
Any help?