Crash on missing version metadata during resolution

[lamdacoolest]

TypeError: expected string or bytes-like object, got 'NoneType'

[ichard26]

We're going to need more information than this. Please share the entire traceback and the command you were running. Thanks!

[lamdacoolest]

PS D:\FIN377\Class-Notes> pip install pandas_datareader
Collecting pandas_datareader
Using cached pandas_datareader-0.10.0-py3-none-any.whl.metadata (2.9 kB)
ERROR: Exception:
Traceback (most recent call last):
File "C:\Users\ASUS\anaconda3\Lib\site-packages\pip_internal\cli\base_command.py", line 105, in _run_wrapper
status = _inner_run()
^^^^^^^^^^^^
File "C:\Users\ASUS\anaconda3\Lib\site-packages\pip_internal\cli\base_command.py", line 96, in _inner_run
return self.run(options, args)
^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\ASUS\anaconda3\Lib\site-packages\pip_internal\cli\req_command.py", line 67, in wrapper
return func(self, options, args)
^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\ASUS\anaconda3\Lib\site-packages\pip_internal\commands\install.py", line 379, in run
requirement_set = resolver.resolve(
^^^^^^^^^^^^^^^^^
File "C:\Users\ASUS\anaconda3\Lib\site-packages\pip_internal\resolution\resolvelib\resolver.py", line 95, in resolve
^^^^^^^^^^^^^^^^^
File "C:\Users\ASUS\anaconda3\Lib\site-packages\pip_vendor\resolvelib\resolvers.py", line 546, in resolve
state = resolution.resolve(requirements, max_rounds=max_rounds)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\ASUS\anaconda3\Lib\site-packages\pip_vendor\resolvelib\resolvers.py", line 427, in resolve
failure_causes = self._attempt_to_pin_criterion(name)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\ASUS\anaconda3\Lib\site-packages\pip_vendor\resolvelib\resolvers.py", line 239, in _attempt_to_pin_criterion
criteria = self._get_updated_criteria(candidate)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\ASUS\anaconda3\Lib\site-packages\pip_vendor\resolvelib\resolvers.py", line 230, in _get_updated_criteria
self._add_to_criteria(criteria, requirement, parent=candidate)
File "C:\Users\ASUS\anaconda3\Lib\site-packages\pip_vendor\resolvelib\resolvers.py", line 148, in _add_to_criteria
matches = self._p.find_matches(
^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\ASUS\anaconda3\Lib\site-packages\pip_internal\resolution\resolvelib\provider.py", line 232, in find_matches
return self._factory.find_candidates(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\ASUS\anaconda3\Lib\site-packages\pip_internal\resolution\resolvelib\factory.py", line 451, in find_candidates
return self._iter_found_candidates(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\ASUS\anaconda3\Lib\site-packages\pip_internal\resolution\resolvelib\factory.py", line 342, in _iter_found_candidates
_get_installed_candidate(),
^^^^^^^^^^^^^^^^^^^^^^^^^^
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PS D:\FIN377\Class-Notes> pip install pandas_datareader
Collecting pandas_datareader
Using cached pandas_datareader-0.10.0-py3-none-any.whl.metadata (2.9 kB)
ERROR: Exception:
Traceback (most recent call last):
File "C:\Users\ASUS\anaconda3\Lib\site-packages\pip_internal\cli\base_command.py", line 105, in _run_wrapper
status = _inner_run()
^^^^^^^^^^^^
File "C:\Users\ASUS\anaconda3\Lib\site-packages\pip_internal\cli\base_command.py", line 96, in _inner_run
return self.run(options, args)
^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\ASUS\anaconda3\Lib\site-packages\pip_internal\cli\req_command.py", line 67, in wrapper
return func(self, options, args)
^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\ASUS\anaconda3\Lib\site-packages\pip_internal\commands\install.py", line 379, in run
requirement_set = resolver.resolve(
^^^^^^^^^^^^^^^^^
File "C:\Users\ASUS\anaconda3\Lib\site-packages\pip_internal\resolution\resolvelib\resolver.py", line 95, in resolve
^^^^^^^^^^^^^^^^^
File "C:\Users\ASUS\anaconda3\Lib\site-packages\pip_vendor\resolvelib\resolvers.py", line 546, in resolve
state = resolution.resolve(requirements, max_rounds=max_rounds)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\ASUS\anaconda3\Lib\site-packages\pip_vendor\resolvelib\resolvers.py", line 427, in resolve
failure_causes = self._attempt_to_pin_criterion(name)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\ASUS\anaconda3\Lib\site-packages\pip_vendor\resolvelib\resolvers.py", line 239, in _attempt_to_pin_criterion
criteria = self._get_updated_criteria(candidate)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\ASUS\anaconda3\Lib\site-packages\pip_vendor\resolvelib\resolvers.py", line 230, in _get_updated_criteria
self._add_to_criteria(criteria, requirement, parent=candidate)
File "C:\Users\ASUS\anaconda3\Lib\site-packages\pip_vendor\resolvelib\resolvers.py", line 148, in _add_to_criteria
matches = self._p.find_matches(
^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\ASUS\anaconda3\Lib\site-packages\pip_internal\resolution\resolvelib\provider.py", line 232, in find_matches
return self._factory.find_candidates(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\ASUS\anaconda3\Lib\site-packages\pip_internal\resolution\resolvelib\factory.py", line 451, in find_candidates
return self._iter_found_candidates(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\ASUS\anaconda3\Lib\site-packages\pip_internal\resolution\resolvelib\factory.py", line 342, in _iter_found_candidates
_get_installed_candidate(),
^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\ASUS\anaconda3\Lib\site-packages\pip_internal\resolution\resolvelib\factory.py", line 288, in _get_installed_candidate
if not specifier.contains(installed_dist.version, prereleases=True):
^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\ASUS\anaconda3\Lib\site-packages\pip_internal\metadata\importlib_dists.py", line 168, in version
return parse_version(self._dist.version)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\ASUS\anaconda3\Lib\site-packages\pip_vendor\packaging\version.py", line 56, in parse
return Version(version)
^^^^^^^^^^^^^^^^
File "C:\Users\ASUS\anaconda3\Lib\site-packages\pip_vendor\packaging\version.py", line 200, in init
match = self._regex.search(version)
^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: expected string or bytes-like object, got 'NoneType'

[lamdacoolest]

i cannot download the packages :(

[ichard26]

You likely have a package installed with broken metadata. It's easiest to simply restart from scratch, deleting and recreating your Python environment.

Alternatively, you can manually remove the offending package with the broken metadata:

• Try running pip list and look for a package with None as the version
• Once identified, run pip show <package> and note the installation location
• You can try to uninstall the package at this point, although it may leave dangling files
• If the error still isn't resolved, go to the folder you noted earlier in File Explorer, and look for folders for folders named either <package> or <package>-<some-version>.dist-info

Better error handling would be ideal.

[notatallshaw]

Also, it's bad practise to use pip to install packages directly into the Anaconda base environment.

If you need to use pip with a conda environment you should create a fresh conda environment, activate it, and install what packages you want into that: https://docs.conda.io/projects/conda/en/latest/user-guide/tasks/manage-environments.html

[notatallshaw]

Also, what version of pip are you using? pip -V

[sbidoul]

This is similar to #13227, likely due to #12656.

[sepehr-rs]

@notatallshaw I think you can close this too after merging #13513