reference using setuptools instead of pip internal

[tejaschumbalkar]

Issue: #113

Reference function using setuptools instead of pip internal function. Reference: pypa/pip#5243

[raimon49]

Thanks for the information.

There is a part in the test code that mocks get_installed_distributions(). It needs to be fixed before merging.

[raimon49]

I understood that it is better not to import functions from pip._internal. However, this ported code seems to have the advantage of working in many user environments.

Will import pkg_resources succeed in all user environments? For example, it seems to exist in pip._vendor.pkg_resources.

[jpmn]

Any hope in seeing a fix for this issue merged in? Using pip=21.3.1, it throws an exception:

File ".venv\Scripts\pip-licenses.exe\__main__.py", line 4, in <module>
File ".venv\lib\site-packages\piplicenses.py", line 44, in <module>
  from pip import get_installed_distributions
ImportError: cannot import name 'get_installed_distributions' from 'pip' (.venv\lib\site-packages\pip\__init__.py)

[raimon49]

@jpmn I haven't decided if I want to merge this PR or not.

Please install the latest version of pip-licenses in your environment and see if it solves the error.

# Update pip-licenses version to 3.5.3 or later
$ pip install -U pip-licenses

[jpmn]

I am using the latest version of pip-licenses, but I had to freeze my pip version until there is a fix. I might consider dropping the library in the medium-term if it is blocking my upgrade of pip.

Don't you experience the same behavior with more recent versions of pip?

[worroc]

This fix is required for many users, it is not acceptable to pin the pip version for a such long time. Is there road map to support pip >= 22?

[raimon49]

@worroc Who are "many users"? If this is about you, we need information about your environment.

At least in my environment it is working with pip 22.x.

$ pip-licenses --with-system
 Name               Version   License
 PTable             0.9.2     BSD License
 botocore           1.21.53   Apache Software License
 jmespath           0.10.0    MIT License
 pip                22.2.2    MIT License
 pip-licenses       3.5.3     MIT License

[raimon49]

This proposal was superseded by another excellent proposal that uses importlib_metadata.