Have inspect.getdoc follow the MRO when a method docstring is only one line.

Feature or enhancement

"Hot" on the heels of 3.5ish's https://github.com/python/cpython/issues/59787 comes another idea: An age old pattern we have in our codebase is for people to put """See base class.""" as the docstring on methods to appease lint tooling demanding a docstring on non-trivial methods. As a consequence code written this way doesn't trigger the inspect.getdoc() feature from #59787 and the help() text in a Notebook for such functions is the content-free oneliner instead of heading up the MRO chain.

I propose a new feature: If the docstring for a method exists but is <= 1 line, follow the MRO as if there were no docstring and return

f"{onelinedoc}:\n{mro_doc}" as the docstring. Do this recursively, but collapse duplicate docstrings gathered along the way so that you could wind up with [good]:

"""See base class:
Fill a hovercraft with eels of the chosen species.

Args:
  species: A set of allowed Eel types.
  count: float, a non-negative number of eels to add. Fractions are allowed.
"""

rather than this degenerate pattern in deep heirarchies that could otherwise result [bad]:

"""See base class:
See base class:
See base class:
Fill a hovercraft with ...
"""

Collapsing identical docstrings along the heirarchy in this case also works for the situation where they're all the same cut and pasted oneliner and nothing else.

從 inspect.getdoc 入口點和 issue 中提出的範例開始。判斷遞迴 MRO 查找應如何處理單行 docstring 和重複文字，然後確認產生的文件是否在沒有重複行的情況下保留所需的展開形式。