List comprehension on a nested list?

Question

I have this nested list:

l = [[\'40\', \'20\', \'10\', \'30\'], [\'20\', \'20\', \'20\', \'20\', \'20\', \'30\', \'20\'], [\'30\', \'20\', \'30\', \'50\', \'         


        

Answer 1

The best way to do this in my opinion is to use python's itertools package.

>>>import itertools
>>>l1 = [1,2,3]
>>>l2 = [10,20,30]
>>>[l*2 for l in itertools.chain(*[l1,l2])]
[2, 4, 6, 20, 40, 60]