Why cProfile module doesn't work with unittest?

Question

I would to use cProfile module to profile my unit tests. But when I run

python -mcProfile mytest.py 

I got 'Ran 0 tests in 0.000s'. Here is the source code of mytest.py

import unittest  class TestBasic(unittest.TestCase):     def testFoo(self):         assert True == True  if __name__ == '__main__':     unittest.main() 

I've tested with other more complex unittests as well. Always got 'Ran 0 tests' if I run it with cProfile. Please help.

UPDATE: My OS is MacOS 10.7 with built-in python 2.7. The same code works properly on ubuntu.

Answer 1

You have to initialize the cProfiler in the Constructor of the test, and use the profile data in destructor -- I use it like that:

from pstats import Stats import unittest  class TestSplayTree(unittest.TestCase):     """a simple test"""      def setUp(self):         """init each test"""         self.testtree = SplayTree (1000000)         self.pr = cProfile.Profile()         self.pr.enable()         print "\n<<<---"      def tearDown(self):         """finish any test"""         p = Stats (self.pr)         p.strip_dirs()         p.sort_stats ('cumtime')         p.print_stats ()         print "\n--->>>"      def xtest1 (self):         pass 

In case that a test waits for input, one needs to call self.pr.disable() before that call, and re-enable it afterwards.

If you prefer pytest the method names are a bit different:

import cProfile import time  class TestProfile:     """ test to illustrate cProfile usage """      def setup_class(self):         self.pr = cProfile.Profile()         self.pr.enable()      def teardown_class(self):         self.pr.disable()         self.pr.print_stats(sort="tottime")      def test_sleep(self):         time.sleep(2) 

Answer 2

Specifying the module explicitly fixed this for me. That is, replacing...

    unittest.main() 

...(which tried to auto-discover what tests it should be running) with...

    unittest.main(module='mytest')  # if in 'mytest.py', or as appropriate for your filename/module 

...allowed proper profiling as python -m cProfile mytest.py.