Suddenly when running tests I get "TypeError: 'NoneType' object is not iterable

Question

This is phenomenally strange for me, things were working PERFECTLY fine until this morning.

When I attempt to run my unit test using the following (I have Python3 soft linked to python)

clear; python manage.py test list tests/  

I now get the following error message:

Traceback (most recent call last):
  File "manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "/usr/lib/python3.4/site-packages/django/core/management        /__init__.py", line 385, in execute_from_command_line
    utility.execute()
  File "/usr/lib/python3.4/site-packages/django/core/management        /__init__.py", line 377, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/usr/lib/python3.4/site-packages/django/core/management/commands    /test.py", line 50, in run_from_argv
    super(Command, self).run_from_argv(argv)
  File "/usr/lib/python3.4/site-packages/django/core/management    /base.py", line 288, in run_from_argv
    self.execute(*args, **options.__dict__)
  File "/usr/lib/python3.4/site-packages/django/core/management/commands    /test.py", line 71, in execute
    super(Command, self).execute(*args, **options)
  File "/usr/lib/python3.4/site-packages/django/core/management    /base.py", line 338, in execute
    output = self.handle(*args, **options)
  File "/usr/lib/python3.4/site-packages/django/core/management/commands    /test.py", line 88, in handle
    failures = test_runner.run_tests(test_labels)
  File "/usr/lib/python3.4/site-packages/django/test/runner.py", line     146, in run_tests
    suite = self.build_suite(test_labels, extra_tests)
  File "/usr/lib/python3.4/site-packages/django/test/runner.py", line     101, in build_suite
    suite.addTests(tests)
  File "/usr/lib64/python3.4/unittest/suite.py", line 60, in addTests
    for test in tests:
TypeError: 'NoneType' object is not iterable

I initially thought that I wrote something that completely messed everything up, so I saved this as a branch, reverted back in the master branch to a commit that I am CERTAIN works but I get the exact same error message.

I can't think of anything I did to make things fail like this, in fact, the above doesn't point to anything I've written which (in my case, I'm relatively new to Python/Django) is making it difficult for me to debug the error.

The ONLY thing I can think of that changed is my installation of The Silver Searcher (I use vim) which I removed and still the same error happens.

I've reinstalled django, but still to no avail.

This is on:

• OpenSuse 13.2
• Django 1.7
• Python 3.4.1

Can someone help me out in

• debugging the cause of this error (so that I don't fall in it again)
• how to go about fixing this?

Thank you

Answer 1

Just had this error, caused by an issue I had solved months ago and accidentally happened upon briefly again.

The problem is that when you specify the directory for django test you should use python notation for the directory, not standard shell notation. For example

Correct - project.tests.test_module

Incorrect - project/tests/test_module.py

Answer 2

I wasn't able to explain WHY this is so, but when I ran the "python manage.py test list/" without specifying the file name, things worked perfectly well.

Thanks to user Ella Shar, I will be changing the scheme/layout I set my tests to the approved dotted format as described in the documentation