Still learning - code efficiency, which of these is better?

[Mekire]

The functions are so short that I would one-line both of them:

def both_ends(string):
    return string[:2] + string[-2:] if len(string) >= 2 else ""


def fix_start(string):
  return string[0] + string[1:].replace(string[0], "*")

An experienced python programmer would have no issue reading either of these.  As a beginner it would certainly be easier to understand separated into more lines.

This isn't really a question of efficiency, but rather of readability.