class Node:
    def __init__(self, edges = set()):
        self.edges = edges


def main():
    foo = Node()
    bar = Node()
    quz = Node()

    foo.edges.add(bar)
    bar.edges.add(foo)

    assert(foo is not bar) # assertion succeeds
    assert(foo is not quz) # assertion succeeds
    assert(bar is not quz) # assertion succeeds
    assert(len(quz.edges) == 0) # assertion fails??


main()
spoiler

Mutable default values are shared across objects. The set in this case.

    • FizzyOrange@programming.dev
      link
      fedilink
      arrow-up
      0
      ·
      10 months ago

      Yeah I tried Ruff about a year ago and it only had really trivial lints so it wasn’t a good replacement for Pylint. Is it on par yet?

      • milkisklim@lemm.ee
        link
        fedilink
        arrow-up
        0
        ·
        edit-2
        10 months ago

        What do you mean by trivial? I am not necessarily the most experienced coder, but it does a great job yelling at me to keep methods short and simple.

        I’d suggest taking five minutes whenever and look up the ruff ruleset to see if it would be helpful for you.

        Also maybe because I don’t know how to use pylint in vs code, but the only semi useful thing it catches for me is if my venv doesn’t have a library the code imports.

        Edit: For example, Ruff has caught this bug (mutable argument defaults) in my code before.