% python binarytest.py 
F.... 
============================================= 
FAIL: testDecimal (__main__.BadInputTest) 
--------------------------------------------- 
Traceback (most recent call last): 
File "binarytest.py", line 27, in testDecimal
self.assertRaises(InvalidBinaryError,Binary,0.5) 
File "/usr/local/Python-2.2 /Lib/unittest.py", 
   line 279, in failUnlessRaises 
   raise self.failureException, excName 
AssertionError: InvalidBinaryError 
----------------------------------------------- 
Ran 5 tests in 0.019s 
FAILED (failure s=1) 

Figure 1: Executing the tests in Listing Two produces this output.