Question

Normally in order to store result in several lists in python, i create before the loop the corresponding empty lists.

A = []
B = []
c = []
D = []
E = []
F = []

for i in range(100):
  # do some stuff

i there a method to create the lists in a single code line (or few)?

Answer 1

If the lists are logically similar (I hope so, because one hundred different variables is violence on programmer), create a dictionary of lists:

list_names = ['a', 'b', 'c' ]
d = {name:[] for name in list_names}

This creates a dictionary:

d = {'a': [], 'b': [], 'c': []}

where you can access individual lists:

d['a'].append(...)

or work on all of them at once:

for v in d.itervalues():
    v.append(...)

The further advantage over individual lists is that you can pass your whole dict to a method.