[Python-ideas] Working with Path objects: p-strings?

[Chris Angelico]

On Tue, Mar 29, 2016 at 10:21 PM, Steven D'Aprano <steve at pearwood.info> wrote:
> Unless I'm missing something, pathlib doesn't support bytes filenames.
> So the question doesn't come up. Any path you can use with pathlib is a
> valid Python string, because you can only create paths using Python
> strings.
>
> So if I have a Linux file b'\xD8\x01', I can't create a path object to
> work with it.

Actually you can. Here's an annotated interactive session illustrating
byte smuggling:

>>> # Create a file using a bytes name
... with open(b'\xD8\x01',"w") as f: f.write("Demo text\n")
...
10
>>> import os, pathlib
>>> # By default, you get text strings.
... os.listdir()
['\udcd8\x01']
>>> os.listdir(".")
['\udcd8\x01']
>>> # But you can request byte strings.
... os.listdir(b".")
[b'\xd8\x01']
>>> # pathlib works with text strings the same way.
... list(pathlib.Path(".").glob("*"))
[PosixPath('\udcd8\x01')]
>>> # And you can cast that to str and open it.
... open(str(pathlib.Path("\uDCD8\x01"))).read()
'Demo text\n'

So it looks like the only missing piece of the puzzle is a way to
construct a Path from a bytes, which would do the same transformation
of \xD8 to \uDCD8.

ChrisA