3 ms·

Well, for good or for bad, python does the same.

• bpicolo 8y ago
  To be fair, there's utility to avoid it: check first or do a .get(). That helps you be expressive about what you think should/should not exist
  • p1necone 8y ago
    I can definitely see the use in that. In some situations a given key not being present would actually be exceptional.
• cpeterso 8y ago
  You can use dict's get() method to get back a None for missing keys instead of throwing a KeyError exception. That avoids the overhead of checking `if key in dict` or catching KeyError.
  • wool_gather 8y ago
    Another option, it's very easy to wrap a dict in a defaultdict: class optionaldict(defaultdict): """ A defaultdict that disregards KeyErrors and returns None for missing keys. """ def __init__(self, *original, **kwargs): super().__init__(lambda: None, *original, **kwargs)
    • Quelklef 8y ago
      This is almost always a bad idea, though; it doesn't distinguish between {k: None}[k] and {}[k]
    • bvrmn 8y ago
      It's not a generic option, you are polluting memory with non-existing keys.