3 ms·

> Even `Path("config.json").read_text()` in a constructor isn't a good idea. If that call is necessary to ensure that the instance has a good/known internal st

• mjr00 2y ago
  You're right that consistent internal state is important, but you can accomplish this with class MyClass: def __init__(self, config: str): self._config = config And if your reaction is "that just means something else needs to call Path("config.json").read_text()", you're absolutely right! It's separation of concerns; let some other method deal with the possibility that `config.json` isn't accessible. In the real world, you'd presumably want even more specific checks that specific config values were present in the JSON file, and your constructor would look more like def __init__(self, host: str, port: int): and you'd validate that those values are present in the same place that loads the JSON. This simple change makes code so much more readable and testable.
  • asplake 2y ago
    Better still, pass the parsed config. Let the app decide how it is configured, and let it deal with any problems.