sphinx-autodoc-typehints | Type hints support for the Sphinx autodoc | Code Analyzer library

After a lot of research, I stumbled on to Mamba doesn't find a solution when mixing conda forge defaults and not specifying Python explicitly 1102. So I just edited nbdev.yml from

Yes, these tracebacks indicate errors. The kinds of errors here are pkg_resources.ContextualVersionConflict which is kind of confusing because they don't have Error in their name. For these traceback blocks the last line is the error, the second to last is the way the error was raised.

pkg_resources.ContextualVersionConflict: (urllib3 1.25.8 (c:\users\dean\anaconda3\lib\site-packages), Requirement.parse('urllib3~=1.25.9'), {'parlai'})

Shows that you urllib3 is at 1.25.8, but it needs to be between 1.25.9 and 1.26.

pkg_resources.ContextualVersionConflict: (Sphinx 2.4.0 (c:\users\dean\anaconda3\lib\site-packages), Requirement.parse('Sphinx>=3.0'), {'sphinx-autodoc-typehints'})

means that your sphinx is 2.4.0 but should be greater than or equal to 3.0.

After some searching there were some flaws with my approach:

• Firstly a "list is a homogeneous structure containing values of one type. As such, List only takes a single type, and every element of that list has to have that type." (source). Consequently, I cannot do something like List[creator.Individual, creator.Individual], but should transform it to List[creator.Individual] or if you have multiple types in the list, you should use an union operator, such as List[Union[int,float]]
• Secondly, the type creator.Individual is not recognized by sphinx as a valid type. Instead I should define it using TypeVar as such:

BinaryIO and TextIO directly subclass IO[bytes] and IO[str] respectively, and add on a few extra methods -- see the definitions in typeshed for the specifics.

So if you need these extra methods, use BinaryIO/TextIO. Otherwise, it's probably best to use IO[...] for maximum flexibility. For example, if you annotate a method as accepting an IO[str], it's a bit easier for the end-user to provide an instance of that object.

Though all this being said, the IO classes in general are kind of messy at present: they define a lot of methods that not all functions will actually need. So, the typeshed maintainers are actually considering breaking up the IO class into smaller Protocols. You could perhaps do the same, if you're so inclined. This approach is mostly useful if you want to define your own IO-like classes but don't want the burden of implementing the full typing.IO[...] API -- or if you're using some class that's almost IO-like, but not quite.

All this being said, all three approaches -- using BinaryIO/TextIO, IO[...], or defining more compact custom Protocols -- are perfectly valid. If the sphinx extension doesn't seem to be able to handle one particular approach for some reason, that's probably a bug on their end.