pip should use the distro module: platform.linux_distribution() has been deprecated in Python 3.5

[vstinner]

• Pip version: development version
• Python version: 3.5
• Operating System: Fedora 24

Description:

"pip install PrettyTable" logs a PendingDeprecationWarning because platform.linux_distribution() has been deprecated in Python 3.5:

.../pip/download.py:93: PendingDeprecationWarning: dist() and linux_distribution() functions are deprecated in Python 3.5
  zip(["name", "version", "id"], platform.linux_distribution()),

I suggest to replace the function with the distro module:

• https://pypi.python.org/pypi/distro
• https://github.com/nir0s/distro

FYI platform.linux_distribution() and platform.dist() have been deprecated by https://bugs.python.org/issue1322

[AbdealiLoKo]

Would this imply that if pip is installed, distro will also be installed ?

Because I want to use distro in my setup.py and would not need to download it inside setup.py or use setup_requires for it if it's available because of pip.

[vstinner]

Would this imply that if pip is installed, distro will also be installed ?

No, I suggest to put it in pip/_vendor/ "hidden" package.

[nir0s]

That would be swell. LMK if I can help.

[xavfernandez]

Seems like a good idea, it would be good to avoid PendingDeprecationWarning on 3.6.
cc @dstufft @pfmoore

[pfmoore]

It's only a tiny module, so I don't see a big issue. As I don't use Linux, I don't have any view on whether distro is the "right" solution here - I don't know what options exist - so I'm OK with whatever the experts agree on.

[dstufft]

I've planned on doing that yes, I jsut hadn't gotten around to it yet.

[nir0s]

If you provide me with the information, I can submit the PR

[xavfernandez]

I've pushed #3906 hopefully I did not forget anything ?

[xavfernandez]

@nir0s hmm for some reason, pip's tests get stuck on pypy with the vendored distro (==0.6.0): any clue ?

[xavfernandez]

My bad, it must have been a glitch in travis. Relaunching the build fixed it.

[chrullrich]

This change breaks pip on Windows fully, completely, and entirely:

(pipve) C:\Daten>python -m pip list
Traceback (most recent call last):
  File "C:\Program Files\Python35\lib\runpy.py", line 174, in _run_module_as_main
    mod_name, mod_spec, code = _get_module_details(mod_name, _Error)
  File "C:\Program Files\Python35\lib\runpy.py", line 133, in _get_module_details
    return _get_module_details(pkg_main_name, error)
  File "C:\Program Files\Python35\lib\runpy.py", line 109, in _get_module_details
    __import__(pkg_name)
  File "c:\daten\projekte\other\pip\pip\__init__.py", line 16, in <module>
    from pip.vcs import git, mercurial, subversion, bazaar  # noqa
  File "c:\daten\projekte\other\pip\pip\vcs\mercurial.py", line 9, in <module>
    from pip.download import path_to_url
  File "c:\daten\projekte\other\pip\pip\download.py", line 40, in <module>
    from pip._vendor import distro
  File "c:\daten\projekte\other\pip\pip\_vendor\distro.py", line 1040, in <module>
    _distroi = LinuxDistribution()
  File "c:\daten\projekte\other\pip\pip\_vendor\distro.py", line 591, in __init__
    if include_lsb else {}
  File "c:\daten\projekte\other\pip\pip\_vendor\distro.py", line 925, in _lsb_release_info
    raise subprocess.CalledProcessError(rc, cmd, err)
subprocess.CalledProcessError: Command 'lsb_release -a' returned non-zero exit status 1

platform.linux_distribution() did not attempt to run an external command to get LSB release information; the new code does, and then stumbles when the attempt to run a non-existing command fails with exit code 1 rather than 127.

If an lsb_release command returning the correct exit status (127) is provided to simulate the expected failure mode, the next failure is this:

(pipve) C:\Daten>python -m pip list
Traceback (most recent call last):
  File "C:\Program Files\Python35\lib\runpy.py", line 174, in _run_module_as_main
    mod_name, mod_spec, code = _get_module_details(mod_name, _Error)
  File "C:\Program Files\Python35\lib\runpy.py", line 133, in _get_module_details
    return _get_module_details(pkg_main_name, error)
  File "C:\Program Files\Python35\lib\runpy.py", line 109, in _get_module_details
    __import__(pkg_name)
  File "c:\daten\projekte\other\pip\pip\__init__.py", line 16, in <module>
    from pip.vcs import git, mercurial, subversion, bazaar  # noqa
  File "c:\daten\projekte\other\pip\pip\vcs\mercurial.py", line 9, in <module>
    from pip.download import path_to_url
  File "c:\daten\projekte\other\pip\pip\download.py", line 40, in <module>
    from pip._vendor import distro
  File "c:\daten\projekte\other\pip\pip\_vendor\distro.py", line 1040, in <module>
    _distroi = LinuxDistribution()
  File "c:\daten\projekte\other\pip\pip\_vendor\distro.py", line 592, in __init__
    self._distro_release_info = self._distro_release_info()
  File "c:\daten\projekte\other\pip\pip\_vendor\distro.py", line 977, in _distro_release_info
    basenames = os.listdir(_UNIXCONFDIR)
FileNotFoundError: [WinError 3] The system cannot find the path specified: '/etc'

[chrullrich]

Note that the full distro package (as opposed to the version integrated into pip) defends itself aggressively against failing in this manner:

(pipve) C:\Daten>python
Python 3.5.2 (v3.5.2:4def2a2901a5, Jun 25 2016, 22:18:55) [MSC v.1900 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import distro
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "c:\daten\projekte\other\distro\distro.py", line 39, in <module>
    raise ImportError('Unsupported platform: {0}'.format(sys.platform))
ImportError: Unsupported platform: win32