Codewars needs your function to return a value to test it. Instead of the print function you should use the return statement.
If you want to test your function just call it this way:
print(likes(names))

Not a kata issue.

Things to read:

• https://github.com/codewars/codewars.com/wiki/Troubleshooting-your-solution#how-do-i-post-to-a-kata-discourse
• https://github.com/codewars/codewars.com/wiki/Troubleshooting-your-solution#expected-the-same