I am learning web dev (python, Django and very very limited amount of html/css and js). Am no expert, but this is my opinion.
To get familiar with the syntax of Python and basics, I would say a smart man can pick it up in about 200-300 hours. Usually around 200 hours.
Then you would have to learn frameworks like Django and a bit of html/css/js if you want to go the web dev route.
You can start cranking out small useful tools by the time you’re 300 hours into it.
To be employable, or to be able to solve basic problems that are worth paying for, I would say it would take at least 500 hours.
Consistency is the key. You can’t spend 100 hours on it, give up for a month and then start again. As with any language, learning is a life long pursuit. But you can start “communicating” in a productive manner is roughly 500ish hours (based on the track am following with python Django).
Like I said, not an expert, and these questions don’t really have answers - only opinions, and this is mine.
If you put in 2 hours a day, you will be surprised how much you know in just 6 months. Time flies, 6 months might seem a lot, but it’s not.