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

I've written this function:

def make_array_single_dimension(l):
    l2 = []

    for x in l:
        if type(x).__name__ == "list":
            l2 += make_array_single_dimension(x)
        else:
            l2.append(x)

    return l2

It works as well!