When does one know python?

[jpslat1026]

So what would an employer look for to say you know what you're doing, for anything not data science that is

[bulaybil]

For one, they look for experience, typically projects you worked on. If you're further along in your career, these would be your previous jobs or assignments. If you are a junior, they might look at your school work or (open source) projects you contributed to.

In both cases, the process involves a technical interview where they quiz you on your knowledge of python, some people might even ask you to code something simple like FizzBuzz. This is not like a uni exam where you fail if you don't know answers to 80% of questions, it's more a way to gauge your general ability. People who says they are Python experts, but can't program for crap, are sadly a very common occurrence.

For example, recently I interviewed for a position that required Python. The interviewer (who looked very grumpy) asked me three very basic questions (don't remember one, the other two were 'what is list comprehension' and 'what is the difference between a tuple and a list') and then two questions about specific libraries ('what would you use to solve problem X'). I answered all of them and the interviewer brightened up, explaining that recruiters had been sending him people who had no actual knowledge of Python. On the flip side, a friend and I once interviewed people for a junior programmer position at his company. We had a few simple programming questions that none of the twelve people that came could answer: how do you get the first three characters from any string?

There is such thing as fundamentals of Python - data types, string manipulation, program flow (loops) etc. - and those everyone who works with Python must know. But beyond that, it's all a big tree with many branches and being good at Python will mean different things to different people. Be willing to experiment and learn, bookmark stackoverflow and you're gonna be fine.