You appear to care about what titles you have. Eventually you will understand that what titles you have doesn't matter, only what you can do. This transition requires time and experience.
Now: "I want to be known as an advanced Python programmer."
In the future: "I want to be an advanced Python programmer."
The second state doesn't really have a title associated with it, because it's about experience and skill, not words.
> I have been coding in python for last one year for my company but it does not increase the expertise level of python.
That's only true if you keep creating the same programs in the same way, over and over. The solution is to program on your own, choose your own projects, don't be limited by what you're required to do for work.
And stop caring about what it's called.
> Any idea idea on how to practically make use of concepts like descriptors etc to understand python in depth?
Yes. Read code examples online and recreate them. Make sure you understand the concepts.
Read code. Explore code. Pair program. See how others would solve a similar coding challenge.
I run a Python training course called Real Python (http://www.realpython.com) and that's exactly the question that we've been pondering. How do we take people to the next level? More importantly: Can we take people to the next level.
I'd love to talk more about this. Email me - michael (at) realpython (dot) com.