gh-136507: Fix mimetypes CLI to handle multiple file parameters

[Wulian233]

• Issue: mimetypes CLI cannot handle multiple file parameters #136507

[Wulian233]

Supplement: #136507 (comment) , so this only in 3.14 and 3.15.

CC: @hugovk could you review this?

[mpkocher]

It's probably a good idea to add both success and failure test case for the multiple provided values (e.g., -e image/jpeg text/html, and -e image/jpeg text/xyz).

[encukou]

Could you also test the failure case?

[Wulian233]

Could you also test the failure case?

Sorry, I might not have understood it well. 9500cb3 Run this test was failing before the fix, now it runs pass after the fix

[mpkocher]

Is return help_text line used?

Either:

• delete return help_text (that branch of the code is never used)
• change return help_text to return "\n".join(results) and delete the other return calls at the end of each for type in args.type block.

[Wulian233]

not used, IDE already given a hint

In addition, test failure case have been added

[mpkocher]

Could you also test the failure case?

Sorry, I might not have understood it well. 9500cb3 Run this test was failing before the fix, now it runs pass after the fix

I believe there needs to be a test for the sys.exit calls. For example the case of error: media type unknown for dragons to stderr with a non-zero exit code.

Note that this appears to be slightly changing the interface from a streaming model to a fail fast on the first error case.

[hugovk]

With this PR we get both results when successful:

❯ ./python.exe -m mimetypes 1.pdf 1.pngtype: application/pdf encoding: Nonetype: image/png encoding: None

Or if it fails on the last one:

❯ ./python.exe -m mimetypes 1.pdf 1.pnxtype: application/pdf encoding: Noneerror: media type unknown for 1.pnx

But not if it fails on the first one (or both):

❯ ./python.exe -m mimetypes 1.pdx 1.pnxerror: media type unknown for 1.pdx

Shall we collect all results and display them all at the end?

❯ ./python.exe -m mimetypes 1.pdx 1.pngerror: media type unknown for 1.pdxtype: image/png encoding: None

Something like this:

diff --git a/Lib/mimetypes.py b/Lib/mimetypes.py index d38c6e1aba2..7d0f4c1fd40 100644 --- a/Lib/mimetypes.py+++ b/Lib/mimetypes.py@@ -718,8 +718,6 @@ def _parse_args(args): def _main(args=None): """Run the mimetypes command-line interface and return a text to print.""" - import sys- args, help_text = _parse_args(args) results = [] @@ -729,17 +727,21 @@ def _main(args=None): if guess: results.append(str(guess)) else: - sys.exit(f"error: unknown type{gtype}")- return '\n'.join(results)+ results.append(f"error: unknown type{gtype}")+ return results else: for gtype in args.type: guess, encoding = guess_type(gtype, not args.lenient) if guess: results.append(f"type:{guess} encoding:{encoding}") else: - sys.exit(f"error: media type unknown for{gtype}")- return '\n'.join(results)+ results.append(f"error: media type unknown for{gtype}")+ return results if __name__ == '__main__': - print(_main())+ import sys++ results = _main()+ print("\n".join(results))+ sys.exit(any(result.startswith("error: ") for result in results))

[Wulian233]

Very thanks! Applyed and fixed test

[hugovk]

Thank you!

[miss-islington-app]

Thanks @Wulian233 for the PR, and @encukou for merging it 🌮🎉.. I'm working now to backport this PR to: 3.14.
🐍🍒⛏🤖

[bedevere-app]

GH-138140 is a backport of this pull request to the 3.14 branch.

[mpkocher]

if name == 'main':

• print(_main())

• import sys
• results = _main()
• print("\n".join(results))
• sys.exit(any(result.startswith("error: ") for result in results))

Why not encapsulate the functionality in _main and have it return tuple[string, int] with the second parameter communicating the exit code?

Also, it would be better if errors were written to stderr, not stdout.