pip install *.whl fails on Windows

[peterjc]

Description

On Linux and macOS I have scripted a build process which makes a wheel, and then (usually in in a clean environment) installs the wheel. The wheel filename depends on the version etc, and by construction there is only one wheel present.

This works on Linux and macOS:

$ cd dist
$ ls *.whl  # confirm exactly one wheel present
$ pip install *.whl

The equivalent fails on Windows:

> cd dist
> dir *.whl
> pip install *.whl
WARNING: Requirement '*.whl' looks like a filename, but the file does not exist
ERROR: *.whl is not a valid wheel filename

Expected behavior

I am expecting pip on Windows to expand the wildcard glob, and substitute the single matching filename.

If this is something you won't fix, suggestions for a workaround would be useful.

pip version

21.1.3

Python version

3.9.5

OS

Windows

How to Reproduce

Contrived test case:

> mkdir dist # new empty dir
> cd dist
> echo > empty.whl
> dir *.whl  # confirm only one wheel
> pip install *.whl

Output

Expected behaviour is to interpret *.whl as empty.whl, thus expect:

ERROR: empty.whl is not a valid wheel filename

Actual:

WARNING: Requirement '*.whl' looks like a filename, but the file does not exist
ERROR: *.whl is not a valid wheel filename

Code of Conduct

• I agree to follow the PSF Code of Conduct.

[pfmoore]

That's a difference in the Windows and Unix shells, not a bug in pip. On Unix, the shell expands *.whl but on Windows it doesn't.

[peterjc]

Yes, I know. But from an end user perspective it is a frustrating behaviour change (which would be supported with the glob library when pip is run on Windows).

So this is considered a won't fix?

On the bright side, I have a work around now:

for %%w in (*.whl) do pip install %%w

Double percentage signs not needed directly at the Windows terminal.

[pfmoore]

I get your point, but making it "work" would be complex - because whether to expand is dependent on the shell, not the OS (bash on Windows is a thing, as is Powershell on Unix), so how would we write the logic? And we don't want to double-expand on shells that do expand, so "expand always" has its own issues.

IMO, it's not so much "won't fix" as "far more complicated than it's worth".

By the way, when you say "behaviour change", I assume you mean "works differently on different systems", not "used to work in older versions of pip"? Because I don't recall that we ever did a manual glob here, but I could be wrong...

[pradyunsg]

This isn't something that pip should handle IMO. This is a platform-specific feature, outside of pip, and I don't think we should try to reconcile differences across platforms.

[peterjc]

I've been away from Windows too long - things like this catch me by surprise. Thanks for the discussion, I agree we can close this.