What are the key features of Python?

a brief explanation of main functions…

Search through DuckDuckGo. This search returns good answers. I checked the first two, these are excellent.

These answer the question in your title. I can not think of any “main functions” in Python, the sole function of a computer language is to enable you to write programs. Find a good tutorial to get a feel for what that entails, see this page to get started.

Key features of Python:

I’m not sure what you mean by “a brief explanation of main functions”.
Do you mean, what are the main functions (uses) of Python?

The main function of Python is to write programs, mostly scripts,
utilities, programs used for data science, text analysis, statistics,
numerical calculations, web development, GUI applications, etc.

Or do you mean, what are main functions in programming?

A “main function” is a function in the program that controls all the
other functions, and performs the main task of that program. For
example, if you have a program that displays a video in a GUI window,
the “main function” would open a window and display the video in it.

Does this help? If not, you will need to be more specific about your
question.