Posting this because it can save some lives. If you use an empty list or dictionary as a default argument in #python, the same list will be used every time. So every call will just update the mutable element instead of re-defining it as empty 😱
Most IDEs will give you a vague warning (PyCharm does) but nothing more so it can be very sneaky and dangerous!
bonifartius 𒂼𒄄
