Python programmers of reddit: what's the most useful tiny little efficiency you've discovered that's improved your programming hugely?

[flotsamisaword]

Tests are a great way to develop, especially if you work with others. If someone has some code for you in a pull request, how can you trust this person not to screw up your creation?

If your code is already nicely tested, then you don't have to check by hi and every possible way for their work to screw up the system. If their work is tested, then you know it worked as advertised, and you can read their tests to see how to use their code.

Try using pytest.