>>> foo = {"foo": None}
>>> print(foo.get('foo', {}).get('bar'))
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
AttributeError: 'NoneType' object has no attribute 'get'
>>> print((foo.get('foo') or {}).get('bar'))
None> Blowing up on `None` is an easy short-circuit.
The thing being discussed is attempting to access deeply nested values, so short-circuiting here is a win-win. I.e., you wouldn't want to unnecessarily traverse tons of empty dictionaries using the `.get() or {}` trick.