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

Here is how you would do this with a nested list comprehension:

[[float(y) for y in x] for x in l]

This would give you a list of lists, similar to what you started with except with floats instead of strings. If you want one flat list then you would use [float(y) for x in l for y in x].