where is FileNotFoundError at?

[Mekire]

Interestingly FileNotFoundError is defined in my py3 install (3.5.1) but the docs seem to indicate using OSError and I can't find documentation for FileNotFoundError.
https://docs.python.org/3/library/except...ml#OSError

In my own personal experience I always caught IOError for this (which seems to be folded into OSError now).

Edit:
Actually here is the doc for FileNotFoundError
https://docs.python.org/3/library/except...FoundError
Sure seems it should still be defined in current distros.

https://www.python.org/dev/peps/pep-3151/