Your two statements don't directly seems to support each other, I'm not sure if I should interpret them separately.
As for the second, there's zillions of things that can explain that and I'm definitely not clear that your being less productive in Python than in C# has anything to do with how much time you've spent on either. Which is the whole point, programming languages aren't equal. Neither are libraries.
If you set aside the time to learn the libraries and narrow it down only to syntax, that certainly the time to learn it will vary from person to person but isn't a multi-month task for anyone. I think you are scoping it in the larger context of non-shared libraries.
The best example I could give would be learning VB.NET when you already know C# (or vice versa).
As for the second, there's zillions of things that can explain that and I'm definitely not clear that your being less productive in Python than in C# has anything to do with how much time you've spent on either. Which is the whole point, programming languages aren't equal. Neither are libraries.
If you set aside the time to learn the libraries and narrow it down only to syntax, that certainly the time to learn it will vary from person to person but isn't a multi-month task for anyone. I think you are scoping it in the larger context of non-shared libraries.
The best example I could give would be learning VB.NET when you already know C# (or vice versa).