issue 6275

Add an "exc_value" attribute to the _AssertRaisesContext context manager in the unittest package.  This allows further tests on the exception that was raised after the context manager exits.

Lib/unittest/case.py

@@ -104,6 +104,7 @@ class _AssertRaisesContext(object):
         if not issubclass(exc_type, self.expected):
             # let unexpected exceptions pass through
             return False
+        self.exc_value = exc_value #store for later retrieval
         if self.expected_regex is None:
             return True