How can I convert a 3D list into a 2D list in python?

Question

This is the code that I have:

[[[3], [4]], [[5], [6]], [[7], [8]]]

How can I change it into:

[[3], [4], [5], [6], [7], [8]]
         


        

Answer 1

A uncompressed or long way:

l3d = [[[3], [4]], [[5], [6]], [[7], [8]]]
l2d = []
for e1 in l3d:
   for e2 in e1:
      l2d.append(e2)