Plenty of well written questions and answers on StackOverflow would go a long way towards convincing me of both your ability to think critically and to communicate with a team.
Companies in my time were happy if you could recreate a couple of dozen Unix command line filters. Nowadays that is not enough. Cross platform scripting in multiple languages is the name of the game. SQL, php, Java and various flavors of C are often seen. An applicant is expected to be conversant in everything from lambda expressions and iterators to complex regexes and html parsers. Rather than jump in to studying all these things however, you should know the things you do know really well and be able to discuss them, in depth, with the interviewer.
If I were to set out an ultimate task list, it would be to code samples of the patterns in this page . When doing these don’t limit yourself to Python, if a call to a DB works then do that, if a call to command line utility satisfies the pattern then do that. It’s not the complexity of the code but your understanding of how the code implements the pattern and the clarity of the interface definition that is the seller.
solved If you were an employer looking at a novice coder, what would you consider a complex enough project to consider them a capable programmer? [closed]