ModuleNotFoundError: No module named corsheaders.middleware

[rowanv]

Hi,

Thanks for forking this and maintaining it given the lack of updates on django-cors-headers. I'm finding that when I follow the installation instructions in the README.md, I get an error that seems to indicate that django-cors-middleware by itself is missing some sort of dependency. When I install both django-cors-headers==2.4.0 and django-cors-middleware=1.3.1, CORS issues are resolved without a problem. Any idea why this might be?

Including error that I got here, using Django==1.11.6.

======================================================================
ERROR: setUpClass (functional_tests.test_my_app.TestMyApp)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/Users/rowan/workspace/beacon/beacon/functional_tests/base.py", line 19, in setUpClass
    super().setUpClass()
  File "/Users/rowan/virtualenvs/beacon/lib/python3.6/site-packages/django/test/testcases.py", line 1352, in setUpClass
    raise cls.server_thread.error
  File "/Users/rowan/virtualenvs/beacon/lib/python3.6/site-packages/django/test/testcases.py", line 1281, in run
    handler = self.static_handler(_MediaFilesHandler(WSGIHandler()))
  File "/Users/rowan/virtualenvs/beacon/lib/python3.6/site-packages/django/core/handlers/wsgi.py", line 151, in __init__
    self.load_middleware()
  File "/Users/rowan/virtualenvs/beacon/lib/python3.6/site-packages/django/core/handlers/base.py", line 80, in load_middleware
    middleware = import_string(middleware_path)
  File "/Users/rowan/virtualenvs/beacon/lib/python3.6/site-packages/django/utils/module_loading.py", line 20, in import_string
    module = import_module(module_path)
  File "/usr/local/Cellar/python/3.6.5/Frameworks/Python.framework/Versions/3.6/lib/python3.6/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 994, in _gcd_import
  File "<frozen importlib._bootstrap>", line 971, in _find_and_load
  File "<frozen importlib._bootstrap>", line 953, in _find_and_load_unlocked
ModuleNotFoundError: No module named 'corsheaders.middleware'

[wsgomes]

In my case, this error happened after installing both (middleware then headers) and then removing middleware. It seems like removing middleware affects headers. To fix, just uninstall both and install one again.

[jamrod]

I had a similar error, "ModuleNotFoundError: No module named 'corsheaders'"
I had to open a terminal outside the virtual environment and install with "python -m pip install django-cors-headers" to fix.