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importlib.metadata.version(None) returns arbitrary version number #93259
Description
The version() function of the importlib.metadata package returns an arbitrary version number when called with None. There's no documentation on what the return value means.
I would have expected one of the following instead:
- raise an error saying that the
distribution_nameparameter cannot beNone, or - explain what the return value means in the relevant documentation.
The current behaviour is confusing as one could think, for example, that the return value is the version of the project/package they call it from.
>>> import sys
>>> print(sys.version)
3.10.0 (tags/v3.10.0:b494f59, Oct 4 2021, 19:00:18) [MSC v.1929 64 bit (AMD64)]
>>> import importlib.metadata
>>> importlib.metadata.version(None)
'21.2.3'
I looks like the return value is the version of an arbitrary package installed in the Python virtual environment. Calling the function repeatedly seems to give the same value, but installing a new package can cause the return value to change.
System information
- CPython versions tested on: 3.10.0
- Operating system and architecture: Windows 10 Enterprise (64-bit operating system, x64-based processor)
Activity
warsaw commentedon May 26, 2022
I can't think of a valid meaning for
distribution_name=Nonein this or any related API. In a fresh checkout of CPythonmain, you do get an exception, but probably not the right one. It should probably quick raise aValueError.@jaraco
jaraco commentedon Jun 23, 2022
I'm unsure whether the input should produce a
ValueErroror aTypeError, but it also occurs to me that an empty string may also produce unexpected results.jaraco commentedon Jun 23, 2022
Hmm. The way it's currently implemented,
distribution_nameis passed through asContext.namewhereNoneis defined to mean "all distributions", andDistribution._from_nameis implemented to return the first matching distribution. I expect the only reason that Barry is getting thePackageNotFoundErroris because he's running in an environment where there are literally no distributions, but if there were a single distribution installed, I'd expect him to get the version for that one.jaraco commentedon Jun 23, 2022
I have a test capturing the failure and a potential fix in the aforementioned PR.
In Distribution.from_name, require a non-empty string. Fixes python/c…
In Distribution.from_name, require a non-empty string. Fixes python/c…
warsaw commentedon Jun 25, 2022
Indeed, and all I need to do to see the difference is invoke Python from a
./python.exe -m venv. Then I get22.0.4(from Python 3.12), which is of course the version of thepipdistribution in the venv.gh-93259: Validate arg to ``Distribution.from_name``. (GH-94270)
Revert 30935 defer bpo45162 to 312 (#94285)
pypi-importlib_metadata: Autospec creation for update from version 4.…