Flatten a list in python

Question

I have a list like this:

[[(video1,4)], [(video2,5),(video3,8)], [(video1,5)], [(video5, 7), (video6,9)]...]

each item in this list may con

Answer 1

If this list is singly-nested (list of lists) you can do this, which I use a lot:

flat_list = sum(list_of_lists, [])

This works due to the fact that sum simply adds up the lists, and adding up lists works in python as expected :)

Note: This is inefficient and some say unreadable.