python map list of lists code example

Example 1: python flat list from list of list

flat_list = [item for sublist in l for item in sublist]

#which is equivalent to this 
flat_list = []
for sublist in l:
    for item in sublist:
        flat_list.append(item)

Example 2: convert list to list of lists on every n elements python

n = 5
my_list_of_lists = [my_list[i:i + n] for i in range(0, len(my_list), n)]