Convert multi-dimensional list to a 1D list in Python

Question

A multidimensional list like l=[[1,2],[3,4]] could be converted to a 1D one by doing sum(l,[]). Can anybody please explain how that happens?

<

Answer 1

It looks to me more like you're looking for a final answer of:

[3, 7]

For that you're best off with a list comprehension

>>> l=[[1,2],[3,4]]
>>> [x+y for x,y in l]
[3, 7]