If you run
import unittest
class Test_Unittest(unittest.TestCase):
def test_assert(self):
assert False
def test_assertFalse(self):
self.assertFalse(True)
if __name__ == '__main__':
unittest.main()
You get the same logging information, the same failure:
FF
======================================================================
FAIL: test_assert (__main__.Test_Unittest)
----------------------------------------------------------------------
Traceback (most recent call last):
File "/home/unutbu/pybin/test.py", line 6, in test_assert
assert False
AssertionError
======================================================================
FAIL: test_assertFalse (__main__.Test_Unittest)
----------------------------------------------------------------------
Traceback (most recent call last):
File "/home/unutbu/pybin/test.py", line 8, in test_assertFalse
self.assertFalse(True)
AssertionError
----------------------------------------------------------------------
Ran 2 tests in 0.000s
FAILED (failures=2)
The reason both are handled the same is because unittest.TestCase
defines
failureException = AssertionError
When you say assert False
an AssertionError is raised.
When you say self.assertFalse(True)
, a failureExeception
is raised.
Since these exceptions are the same, there is no apparent difference.
assert
and self.assertFalse
do differ in conventional usage, however.
assert
is used to declare that a certain condition should hold at a certain point in the code. It is used as a crutch during development, but is not meant to be used in production code. If you run python -O my_unittest.py
, all assert statements are ignored. That would subvert your intended usage of assert
, possibly making your unit tests pass even when there is a failure.
Even though (without the -O flag) the result is the same, assert
is not meant to be used in unit test code. Use self.assertTrue
or self.assertFalse
when writing unit tests.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…