Python Error when installing ruamel.yaml package with pip

Question

I am receiving an error when I want to install the ruamel.yaml package

Here is the command:

python --version;pip --version;pip install ruamel.yaml

And the output:

Python 2.7.10
pip 10.0.0 from /Library/Python/2.7/site-packages/pip (python 2.7)
Collecting ruamel.yaml
  Downloading https://files.pythonhosted.org/packages/c1/ad/9557a78f1b61951623c56225e05dacdd81f80519f13fc39a926a5793edfa/ruamel.yaml-0.15.37.tar.gz (280kB)
    100% |████████████████████████████████| 286kB 4.4MB/s
    Complete output from command python setup.py egg_info:
    sys.argv ['-c', 'egg_info', '--egg-base', 'pip-egg-info']
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/private/var/folders/8j/69k5q3yn4y51g5nt2g7g9b9n24s68p/T/pip-install-htyM8C/ruamel.yaml/setup.py", line 917, in <module>
        main()
      File "/private/var/folders/8j/69k5q3yn4y51g5nt2g7g9b9n24s68p/T/pip-install-htyM8C/ruamel.yaml/setup.py", line 905, in main
        setup(**kw)
      File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/core.py", line 111, in setup
        _setup_distribution = dist = klass(attrs)
      File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/setuptools/dist.py", line 272, in __init__
        _Distribution.__init__(self,attrs)
      File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/dist.py", line 287, in __init__
        self.finalize_options()
      File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/setuptools/dist.py", line 326, in finalize_options
        ep.require(installer=self.fetch_build_egg)
      File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/pkg_resources/__init__.py", line 2385, in require
        reqs = self.dist.requires(self.extras)
      File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/pkg_resources/__init__.py", line 2617, in requires
        dm = self._dep_map
      File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/pkg_resources/__init__.py", line 2606, in _dep_map
        if invalid_marker(marker):
      File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/pkg_resources/__init__.py", line 1424, in is_invalid_marker
        cls.evaluate_marker(text)
      File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/pkg_resources/__init__.py", line 1549, in _markerlib_evaluate
        env = cls._translate_metadata2(_markerlib.default_environment())
      File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/pkg_resources/__init__.py", line 1537, in _translate_metadata2
        for key, value in env
      File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/pkg_resources/__init__.py", line 1536, in <genexpr>
        (key.replace('.', '_'), value)
    ValueError: too many values to unpack

    ----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /private/var/folders/8j/69k5q3yn4y51g5nt2g7g9b9n24s68p/T/pip-install-htyM8C/ruamel.yaml/

To give a bit of a background. I installed python3 with brew and I uninstalled it thereafter.

Now I cannot install ruamel.yaml

Has anybody had the same issue? How did you solve it?

Answer 1

You should do a pip list and check your version of setuptools should be (28.8.0). If you have an older version, upgrade with pip install -U setuptools.

You should consider upgrading from 2.7.10 to a newer version of Python 2 (currently 2.7.14), which should solve your SSL problems. Make sure you don't overwrite the system python if you are running on Linux.