On 8/10/2019 11:16 AM, Terry Reedy wrote:
On 8/10/2019 4:33 AM, Paul Moore wrote:

(Side issue)

This deserves its own thread.

As a Windows developer, who has seen far too many cases where use of
slashes in filenames implies a Unix-based developer not thinking
sufficiently about Windows compatibility, or where it leads to people
hard coding '/' rather than using os.sep (or better, pathlib), I
strongly object to this characterisation. Rather, I would simply say
"to make Windows users more aware of the clash in usage between
backslashes in filenames and backslashes as string escapes".

There are *many* valid ways to write Windows pathnames in your code:

1. Raw strings

As pointed out elsewhere, Raw strings have limitations, paths ending in \ cannot be represented, and such do exist in various situations, not all of which can be easily avoided... except by the "extra character contortion" of   "C:\directory\ "[:-1]  (does someone know a better way?)

It would be useful to make a "really raw" string that doesn't treat \ special in any way. With 4 different quoting possibilities ( ' " ''' """ ) there isn't really a reason to treat \ special at the end of a raw string, except for backward compatibility.

I wonder how many raw strings actually use the \"  escape productively? Maybe that should be deprecated too! ?  I can't think of a good and necessary use for it, can anyone?

Or invent "really raw" in some spelling, such as     rr"c:\directory\"
or e for exact, or x for exact, or <your favorite character here>"c:\directory\"

And that brings me to the thought that if   \e  wants to become an escape for escape, that maybe there should be an "extended escape" prefix... if you want to use more escapes, define   ee"string where \\ can only be used as an escape or escaped character, \e means the ASCII escape character, and \ followed by a character with no escape definition would be an error."

Of course "extended escape" could be spelled lots of different ways too, but not the same way as "really raw" :)

2. Doubling the backslashes
3. Using pathlib (possibly with slash as a directory separator, where
it's explicitly noted as a portable option)
4. Using slashes

IMO, using slashes is the *worst* of these. But this latter is a
matter of opinion - I've no objection to others believing differently,
but I *do* object to slashes being presented as the only option, or
the recommended option without qualification.

Perhaps Python Setup and Usage, 3. Using Python on Windows, should have a section of file paths, at most x.y.z, so visible in the TOC listed by https://docs.python.org/3/using/index.html