Python Nose Import Error

Question

I can't seem to get the nose testing framework to recognize modules beneath my test script in the file structure. I've set up the simplest example that demonstrates the problem. I'll explain it below.

Here's the the package file structure:

./__init__.py
./foo.py
./tests
   ./__init__.py
   ./test_foo.py

foo.py contains:

def dumb_true():
    return True

tests/test_foo.py contains:

import foo

def test_foo():
    assert foo.dumb_true()

Both init.py files are empty

If I run nosetests -vv in the main directory (where foo.py is), I get:

Failure: ImportError (No module named foo) ... ERROR

======================================================================
ERROR: Failure: ImportError (No module named foo)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/lib/python/site-packages/nose-0.11.1-py2.6.egg/nose/loader.py", line 379, in loadTestsFromName
    addr.filename, addr.module)
  File "/usr/lib/python/site-packages/nose-0.11.1-py2.6.egg/nose/importer.py", line 39, in importFromPath
    return self.importFromDir(dir_path, fqname)
  File "/usr/lib/python/site-packages/nose-0.11.1-py2.6.egg/nose/importer.py", line 86, in importFromDir
    mod = load_module(part_fqname, fh, filename, desc)
  File "/home/user/nose_testing/tests/test_foo.py", line 1, in <module>
    import foo
ImportError: No module named foo

----------------------------------------------------------------------
Ran 1 test in 0.002s

FAILED (errors=1)

I get the same error when I run from inside the tests/ directory. According to the documentation and an example I found, nose is supposed to add all parent packages to the path as well as the directory from which it is called, but this doesn't seem to be happening in my case.

I'm running Ubuntu 8.04 with Python 2.6.2. I've built and installed nose manually (not with setup_tools) if that matters.

Answer 1

Another potential problem appears to be hyphens/dashes in the directory tree. I recently fixed a nose ImportError issue by renaming a directory from sub-dir to sub_dir.

Answer 2

You've got an __init__.py in your top level directory. That makes it a package. If you remove it, your nosetests should work.

If you don't remove it, you'll have to change your import to import dir.foo, where dir is the name of your directory.

Answer 3

I just ran into one more thing that might cause this issue: naming of tests in the form testname.test.py. That extra . confounds nose and leads to it importing things it should not. I suppose it may be obvious that using unconventional test naming conventions will break things, but I thought it might be worth noting.