The following IDLE files need docstrings for their methods:

GrepDialog.py
SearchEngine.py
SearchDialogBase.py
SearchDialog.py
ReplaceDialog.py

Current module names, docstring status, and note.

grep - present, some args not doc'ed
replace - spotty; do not repetively doc 'event=None' args
search - ditto
searchbase - present
searchengine - present; do not separately docstring 'isxyz' wrappers

Closing """ must be on line by itself.

Parts of the patch should be usable at least as 'first drafts' for filling in missing docstrings.  I am not sure whether better to edit diff (maybe after splitting into diffs for each module) and apply (I have never done this with git) or to edit modules directly.

Cheryl, another one you might want to grab.

I've created the first PR for docstrings on replace.  Saimadhav Heblikar had added some docstrings under issue 21676, so I expanded on what he did.  I referred to Al's diff, but didn't use it much since there were already some docstrings.

For readability, I also changed some boolean values from 0 to False and 1 to True.  I had to figure out what `ok` did, so that helped.

I also left a note in `show_hit` because it isn't working right.  The text gets colorized with the `sel` tag instead of the `hit` tag.  effbot says this about tag ordering:
>>> If you attach multiple tags to a range of text, style options from the most recently created tag override options from earlier tags. In the following example, the resulting text is blue on a yellow background.

>>>    text.tag_config("n", background="yellow", foreground="red")
>>>    text.tag_config("a", foreground="blue")
>>>    text.insert(contents, ("n", "a"))

>>> Note that it doesn’t matter in which order you attach tags to a range; it’s the tag creation order that counts.

The note seems to be the important part here as the definition for `sel` is done before `hit` in colorizer.

There are several minor things to fix after this (and multiple issues), including the difference between find in search and replace.  It seems to me that is should be the same.  We will definitely need to test changes on both Windows and Linux.

The font color issue is essentially the one that resulted in white on white in the completions box.  We should always set both foreground and background to make sure consistent.  Another nit for followup.

New changeset 0bb5e75cf8bc9b197ffb91cba6f30543ed502708 by Cheryl Sabella in branch 'master':
bpo-23216: IDLE: Add docstrings to search modules (GH-12141)
https://github.com/python/cpython/commit/0bb5e75cf8bc9b197ffb91cba6f30543ed502708

New changeset b34f1aa81433d60aee7bd744352b347dd650ca84 by Miss Islington (bot) in branch '3.7':
bpo-23216: IDLE: Add docstrings to search modules (GH-12141)
https://github.com/python/cpython/commit/b34f1aa81433d60aee7bd744352b347dd650ca84