gistfile1.py

$ cat tests/TestSequenceFunctions.py           
import random
import unittest

class TestSequenceFunctions(unittest.TestCase):

    def setUp(self):
        self.seq = range(10)

    def test_shuffle(self):
        # make sure the shuffled sequence does not lose any elements
        random.shuffle(self.seq)
        self.seq.sort()
        self.assertEqual(self.seq, range(10))

        # should raise an exception for an immutable sequence
        self.assertRaises(TypeError, random.shuffle, (1,2,3))

$ python -m unittest tests.TestSequenceFunctions
Traceback (most recent call last):
  File "/usr/lib/python2.7/runpy.py", line 162, in _run_module_as_main
    "__main__", fname, loader, pkg_name)
  File "/usr/lib/python2.7/runpy.py", line 72, in _run_code
    exec code in run_globals
  File "/usr/lib/python2.7/unittest/__main__.py", line 12, in <module>
    main(module=None)
  File "/usr/lib/python2.7/unittest/main.py", line 94, in __init__
    self.parseArgs(argv)
  File "/usr/lib/python2.7/unittest/main.py", line 149, in parseArgs
    self.createTests()
  File "/usr/lib/python2.7/unittest/main.py", line 158, in createTests
    self.module)
  File "/usr/lib/python2.7/unittest/loader.py", line 128, in loadTestsFromNames
    suites = [self.loadTestsFromName(name, module) for name in names]
  File "/usr/lib/python2.7/unittest/loader.py", line 91, in loadTestsFromName
    module = __import__('.'.join(parts_copy))
ImportError: No module named tests


... I don't get it. I thought a path corresponds to the module name.