Creating a list within a list in Python

Question

I have a list named values containing a series of numbers:

values = [0, 1, 2, 3, 4, 5, ... , 351, 0, 1, 2, 3, 4, 5, 6, ... , 750, 0, 1, 2, 3, 4, 5, ... , 559]
         


        

Answer 1

You can group your elements with itertools.groupby based on the presence of 0 (which is falsy) and extract the sublists between 0 while appending the missing 0 with a list comprehension:

 [[0]+list(g) for k, g in groupby(values, bool) if k]

Example:

>>> from itertools import groupby
>>> values = [0, 1, 2, 3, 4, 5 , 351, 0, 1, 2, 3, 4, 5, 6, 750, 0, 1, 2, 3, 4, 559]
>>> [[0]+list(g) for k, g in groupby(values, bool) if k]
[[0, 1, 2, 3, 4, 5, 351], [0, 1, 2, 3, 4, 5, 6, 750], [0, 1, 2, 3, 4, 559]]