A deep understanding of the programming language of choice is the most important thing in being an expert. This will always be true for any technology. Still, it is really hard to develop good software without knowing the common tools and practices that are common within the given language community. Python has no single feature that cannot be found in some other language. So, in direct comparison of syntax, expressiveness, or performance, there will always be a solution that is better in one or more fields. But, the area in which Python really stands out from the crowd is the whole ecosystem built around the language. The Python community spent years polishing standard practices and libraries that help to create more reliable software in a shorter time.
The most obvious and important part of the ecosystem is a huge collection of free and...