Working with itertools.product and lists in python 3

You can use *pool to "unpack" the list when calling product():

for n in itertools.product(*pool):
   print(n)

This syntax expands the list pool into separate positional parameters.

itertools.product(pool[0],pool[1],...pool[len(pool)-1]) is equivalent to itertools.product(*pool)

import itertools

F = ['UUU', 'UUC']
I = ['AUU', 'AUC', 'AUA']

pool=[F,I]

for n in itertools.product(*pool):
   print(''.join(n))