I'm spawning this issue of as a separate feature from https://bugs.python.org/issue36906 (adding string dedent method and an optimization to do it at compile timer on constants).

It'd be great if docstrings were given a similar treatment.  Right now we carry the whitespace burden within the str constants for __doc__ stored in all code objects in the process.  This adds up.

This is not _quite_ the same as calling textwrap.dedent() or the upcoming str.dedent method on them at compile time.  We need to special case the first line of docstrings.  inspect.getdoc() is our library function that does this for us today.

Change of breaking things with this change?  not impossible, but extremely minor.  Something using docstrings as data _and_ depending on leading indentation whitespace preservation would not like this.  I am not aware of anything that would ever do that.

Hi, I'm working on a PR. It should be ready in a couple of days. It's more involved than what I thought as to avoid importing inspect during compilation I will probably need to port cleandoc() in C.

How about do `inspect.cleandoc()` instead of just a dedent?
Some method has docstring like this:

    """First line

    blah blah blah blah

        example code here
    ...
    """

In such docstring, dedent can not strip indent well.

There is existing attempt (in Japanese):

https://qiita.com/hhatto/items/3da6c6820817395f2c39#%E6%84%9A%E7%9B%B4%E3%81%AB%E5%AE%9F%E8%A3%85%E3%81%97%E3%81%9F%E3%82%B3%E3%83%BC%E3%83%89

This is the function I inlined and as far as I can tell, my approach as been similar to the one you linked.

I'm still need to fix some issues as doctest was expecting to find the string before dedenting though.