Tests succeed, still get traceback

Question

I'm using Python's unittest library and all the tests succeed, but I still get a traceback and I can't understand how I can fix the problem.

........
----------------------------------------------------------------------
Ran 8 tests in 0.020s

OK

Traceback (most recent call last):
  File "C:\Users\Paul\Desktop\bloomfilter\test_bloomfilter.py", line 85, in <module>
    unittest.main()
  File "C:\Programming\PythonX86\Python27\lib\unittest\main.py", line 95, in __init__
    self.runTests()
  File "C:\Programming\PythonX86\Python27\lib\unittest\main.py", line 231, in runTests
    sys.exit(not self.result.wasSuccessful())
SystemExit: False
>>>

Does [this](http://stackoverflow.com/questions/79754/unittest-causing-sys-exit) help any? [For example, passing exit=False to main.) — DSM, Feb 08 '12 at 22:55

score 21 · Answer 1 · edited Jan 23 '19 at 11:04

21

To avoid the end of execution traceback:

if __name__ == '__main__':
    unittest.main(exit=False)

edited Jan 23 '19 at 11:04

Ratmir Asanov

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answered Feb 13 '14 at 02:45

Florent B.

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elegant, concise, precise. – Dan Niero Feb 14 '22 at 11:07

score 16 · Accepted Answer · answered Feb 08 '12 at 22:58

It appears that you are running in the Python shell, which catches exceptions for you so you can continue debugging. If you had been running from the command line, the line

sys.exit(not self.result.wasSuccessful())

would have exited your program with an exit code of 0, which indicates success (this might be counterintuitive if you're unfamiliar with how programs interact with the shell). Since you're running in the interpreter, however, the exception is caught.

I would suggest that there is nothing wrong with your program or your tests. The unittests framework probably just didn't expect to be run interactively!

Remi · Answer 3 · 2012-06-22T09:18:07.787

7

end your unittest file with:

if __name__=='__main__':
    try:
        unittest.main()
    except SystemExit as inst:
        if inst.args[0] is True: # raised by sys.exit(True) when tests failed
            raise

edited Jun 22 '12 at 09:18

answered Jun 21 '12 at 20:19

Remi

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You shouldn't check for `is True` - should just delete that part. Instead of all of this, though, you should instead provide `exit=False`... – Russia Must Remove Putin May 24 '17 at 18:07

Russia Must Remove Putin · Answer 4 · 2016-04-21T02:03:43.433

`sys.exit(not self.result.wasSuccessful())`

I ran into this when I assumed my __main__.py in my Python package would always have the __name__, "__main__" - but when I ran my unittests through discovery there, I found that they would be executed but with a different __name__ - "package.__main__".

Therefore I did need the following in my __main__.py just like in simple Python scripts:

if __name__ == '__main__':
    main()

instead of just

main()

If the main is unittest.main, call it with

if __name__ == '__main__':
    main(exit=False)

if you want the process to stick around in interactive mode if you're calling

python -im package_name

If you're using:

python -m unittest discover

then I don't think exit=False should matter.

The most complete and useful answer here. Man I hate how late answers get such a raw deal. — candied_orange, May 24 '17 at 06:24

score 1 · Answer 5 · answered Feb 08 '12 at 22:55

Whatever you're using to run these tests, it's catching the SystemExit exception and printing the traceback. When you write code that catches exceptions, you should take care to not catch exceptions that you don't actually want to catch, like SystemExit (raised by sys.exit() to end the program) and usually KeyboardInterrupt (raised by control-C.)

Tests succeed, still get traceback

5 Answers5

`sys.exit(not self.result.wasSuccessful())`

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