title: Pylint: "Problem importing module ....: cannot import name 'Type'"
body: <p>Every run of pylint (no matter what program is checked) produces the following error message:</p>
  
  <pre><code>(env) $ pylint hello.py 
  Problem importing module logging.py: cannot import name 'Type'
  Problem importing module spelling.py: cannot import name 'Type'
  Problem importing module python3.py: cannot import name 'Type'
  Problem importing module typecheck.py: cannot import name 'Type'
  Problem importing module variables.py: cannot import name 'Type'
  Problem importing module refactoring.py: cannot import name 'Type'
  Problem importing module format.py: cannot import name 'Type'
  Problem importing module imports.py: cannot import name 'Type'
  Problem importing module utils.py: cannot import name 'Type'
  Problem importing module newstyle.py: cannot import name 'Type'
  Problem importing module exceptions.py: cannot import name 'Type'
  Problem importing module classes.py: cannot import name 'Type'
  Problem importing module stdlib.py: cannot import name 'Type'
  Problem importing module async.py: cannot import name 'Type'
  Problem importing module design_analysis.py: cannot import name 'Type'
  Problem importing module base.py: cannot import name 'Type'
  Problem importing module strings.py: cannot import name 'Type'
  Traceback (most recent call last):
    File "/Users/brunorijsman/python-logging-performance/env/bin/pylint", line 11, in &lt;module&gt;
      sys.exit(run_pylint())
    File "/Users/brunorijsman/python-logging-performance/env/lib/python3.5/site-packages/pylint/__init__.py", line 20, in run_pylint
      Run(sys.argv[1:])
    File "/Users/brunorijsman/python-logging-performance/env/lib/python3.5/site-packages/pylint/lint.py", line 1557, in __init__
      linter.enable("c-extension-no-member")
    File "/Users/brunorijsman/python-logging-performance/env/lib/python3.5/site-packages/pylint/utils.py", line 323, in enable
      msgid, enable=True, scope=scope, line=line, ignore_unknown=ignore_unknown
    File "/Users/brunorijsman/python-logging-performance/env/lib/python3.5/site-packages/pylint/utils.py", line 366, in _set_msg_status
      msg = self.msgs_store.get_message_definition(msgid)
    File "/Users/brunorijsman/python-logging-performance/env/lib/python3.5/site-packages/pylint/utils.py", line 989, in get_message_definition
      msgid_or_symbol=msgid_or_symbol
  pylint.exceptions.UnknownMessageError: No such message id c-extension-no-member
  </code></pre>
  
  <p>In this particular case, I was checking the following trivial program <code>hello.py</code>:</p>
  
  <pre><code>print("Hello")
  </code></pre>
  
  <p>But the problem also occurs when I don't check a program, e.g. <code>pylint --version</code></p>
  
  <p>Pylint is running in a virtual environment which I created as follows:</p>
  
  <pre><code>$ python3 -m virtualenv env
  Using base prefix '/Library/Frameworks/Python.framework/Versions/3.5'
  New python executable in /Users/brunorijsman/python-logging-performance/env/bin/python3
  Also creating executable in /Users/brunorijsman/python-logging-performance/env/bin/python
  Installing setuptools, pip, wheel...done.
  $ source env/bin/activate
  (env) $
  </code></pre>
  
  <p>(Note: I realize that module venv is recommended over virtualenv these days, but I have different problems with venv on macOS as described in <a href="https://stackoverflow.com/questions/49748063/pip-install-fails-for-every-package-could-not-find-a-version-that-satisfies">&#39;pip install&#39; fails for every package (&quot;Could not find a version that satisfies the requirement&quot;)</a>)</p>
  
  <p>I installed pylint into the virtual environment as follows:</p>
  
  <pre><code>(env) $ pip install pylint
  Collecting pylint
    Using cached https://files.pythonhosted.org/packages/a5/06/ecef826f319055e6b231716730d7f9047dd7524ffda224b521d989f085b6/pylint-2.2.2-py3-none-any.whl
  Collecting isort&gt;=4.2.5 (from pylint)
    Using cached https://files.pythonhosted.org/packages/1f/2c/22eee714d7199ae0464beda6ad5fedec8fee6a2f7ffd1e8f1840928fe318/isort-4.3.4-py3-none-any.whl
  Collecting astroid&gt;=2.0.0 (from pylint)
    Using cached https://files.pythonhosted.org/packages/fc/53/8809bc008bad0300897281a7b320b286dc0e84e836396c0cff6279841e8a/astroid-2.1.0-py3-none-any.whl
  Collecting mccabe (from pylint)
    Using cached https://files.pythonhosted.org/packages/87/89/479dc97e18549e21354893e4ee4ef36db1d237534982482c3681ee6e7b57/mccabe-0.6.1-py2.py3-none-any.whl
  Collecting typed-ast; python_version &lt; "3.7" and implementation_name == "cpython" (from astroid&gt;=2.0.0-&gt;pylint)
  Collecting wrapt (from astroid&gt;=2.0.0-&gt;pylint)
  Collecting six (from astroid&gt;=2.0.0-&gt;pylint)
    Using cached https://files.pythonhosted.org/packages/67/4b/141a581104b1f6397bfa78ac9d43d8ad29a7ca43ea90a2d863fe3056e86a/six-1.11.0-py2.py3-none-any.whl
  Collecting lazy-object-proxy (from astroid&gt;=2.0.0-&gt;pylint)
  Installing collected packages: isort, typed-ast, wrapt, six, lazy-object-proxy, astroid, mccabe, pylint
  Successfully installed astroid-2.1.0 isort-4.3.4 lazy-object-proxy-1.3.1 mccabe-0.6.1 pylint-2.2.2 six-1.11.0 typed-ast-1.1.0 wrapt-1.10.11
  </code></pre>
  
  <p>Version info:</p>
  
  <p>Operating system is macOS High Sierra 10.13.6</p>
  
  <pre><code>(env) $ python --version
  Python 3.5.1
  </code></pre>