.... ---------------------------------------------------------------------- Ran 4 tests in 0.000s OK 1 2 3 4 ('empty', None, None, 'val') None <_sre.SRE_Match object at 0x7fe28d5d6d30> <_sre.SRE_Match object at 0x7fe28d5d6d30> Negation <_sre.SRE_Match object at 0x7fe28d5d6d30>