Well, it's definitely up to how fast you can learn and your solution-solving skills.
Although Python is quite an easy programming language, I would not underestimate the difficulty of finding solutions for each problem.
Learning the language, itself can take you a lot. However, it can also take you a little.
Personally, it took me 3 months to properly know the Python language. Then it took me 6 more to get to the advanced level with it -
So if you are looking for a number, I guess around 6-9 months to be at least medium-advanced level.
Of course, this does not apply to everyone, as we are all different. Hence the duration can be longer or less long.