A lot of people have already pointed out that the person saying it is an important detail. If your mom says you’re good at python, I’m going to get a very different idea about your skill level compared to your boss saying it.
Unless you are selling yourself in an interview context, I think it’s very poor form to qualify your own skill level. Let the skill speak for itself, it’s enough to say that you ‘do python’. Saying you’re good at something often comes off as braggadocios more than it is informative. If you must give context, it’s better to talk about how much experience you have, or other objective metrics
Qualifiers are too context dependant and no matter where your skill level is at, you wont ever have enough context to know how good you actually are, because you can’t know what you don’t know.
Nice to see curation used for something other than memes and hate groups