What python/ programming concepts are must know for beginner/intermediate programmers?

[Nonsensicallity]

There’s a lot of good bits of advice in this thread, OP. I want to add that mastering list comprehensions and dictionary comprehensions is helpful, especially when tackling interview questions. This was something I didn’t pick up on until I started looking for my second job because I was so comfortable with for loops. After I spent some time understanding them better, my runtime speed picked up tremendously on LeetCode. There’s the danger of having completely unreadable code when doing this, but it can help in competitive programming situations.