list_repositories = ['repository_one', 'repository_two', 'repository_three', 'repository_four'] repositories_versions = ['1.09', '3.11.a', '14.1.01', '1.a.14'] Outcome I wish to get: repositories = ['repository_one:1.09', 'repository_two:3.11.a', 'repository_three:14.1.01', 'repository_four:1.a.14'] So add the first value from the 2nd list to the first value from the 1st list with a colon in between. Obviously I tried: repositories = list_repositories + repositories_versions But this gets me the following output: ['repository_one', 'repository_two', 'repository_three', 'repository_four', '1.09', '3.11.a', '14.1.01', '1.a.14'] Continue reading...