title: Pipenv trouble on MacOS "TypeError: 'module' object is not callable"
body: <p>I'm starting to try and get a working pipenv, however on my Mac, it is appears that my Python enviroment is a little screwed. I removed OS X python following this <a href="https://stackoverflow.com/questions/3819449/how-to-uninstall-python-2-7-on-a-mac-os-x-10-6-4">post</a> , and installed both python2.7 and python3.7 using brew. But now when trying to use pipenv(2.7) to create a virtualenv, and pipfile, I keep getting an error about python 3.7, when locking pacakges:</p>
  
  <pre><code>$ pipenv --python=/usr/local/bin/python install pynetbox ipaddress
  Virtualenv already exists!
  Removing existing virtualenv...
  Creating a virtualenv for this project...
  Pipfile: /Users/daniel/scripts/netbox/Pipfile
  
  ...
  
  adding ipaddress to Pipfile's [packages]...
  Pipfile.lock not found, creating...
  Locking [dev-packages] dependencies...
  Locking [packages] dependencies...
  c/lib/python3.7/site-packages/pipenv/utils.py", line 250, in actually_resolve_deps
      req = Requirement.from_line(dep)
    File "/usr/local/Cellar/pipenv/2018.7.1/libexec/lib/python3.7/site-packages/pipenv/vendor/requirementslib/models/requirements.py", line 704, in from_line
      line, extras = _strip_extras(line)
  TypeError: 'module' object is not callable
  /usr/local/Cellar/pipenv/2018.7.1/libexec/lib/python3.7/site-packages/pipenv/_compat.py:113: ResourceWarning: Implicitly cleaning up &lt;TemporaryDirectory '/var/folders/pc/hlxw3whn3cl1x3h45ll2m8gw0000gs/T/pipenv-TYWa8Y-requirements'&gt;
    warnings.warn(warn_message, ResourceWarning)
  </code></pre>
  
  <p>I have reinstalled PIP, and python a few times, and no luck. Any ideas would be greatly appreciated. Im sure by python is probably just in some bad state :(</p>