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.

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)

This is almost always a bad idea, though; it doesn't distinguish between

    {k: None}[k]

and

    {}[k]

It's not a generic option, you are polluting memory with non-existing keys.

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

I can definitely see the use in that. In some situations a given key not being present would actually be exceptional.