Support string representation for all DNSExceptions.

Doc string is used in cases where more specific message was not provided
during instantiation/raise.

1 files changed, 6 insertions, 1 deletions

diff --git a/dns/exception.py b/dns/exception.py
index db6ef6e..575cebe 100644
--- a/dns/exception.py
+++ b/dns/exception.py
@@ -17,7 +17,12 @@
 
 class DNSException(Exception):
     """Abstract base class shared by all dnspython exceptions."""
-    pass
+    def __init__(self, *args):
+        if args:
+            super(DNSException, self).__init__(*args)
+        else:
+            # doc string is better implicit message than empty string
+            super(DNSException, self).__init__(self.__doc__)
 
 class FormError(DNSException):
     """DNS message is malformed."""