How to join strings from a Cartesian product of two lists

Question

I have two lists of strings:

letters = [\'abc\', \'def\', \'ghi\']
numbers = [\'123\', \'456\']

I want to for loop through them to create a lis

Answer 1

You can try list comprehension with two nested for loop over numbers and then letters :

print([l+n for n in numbers for l in letters])
# ['abc123', 'def123', 'ghi123', 'abc456', 'def456', 'ghi456']

You can also use nested for loop:

out = []
for n in numbers:
    for l in letters:
        out.append(l+n)
print(out)
# ['abc123', 'def123', 'ghi123', 'abc456', 'def456', 'ghi456']

For more details on list comprehension, see either the doc or this related topic.