Derive exception classes from Exception

Lib/tabnanny.py

@@ -47,7 +47,7 @@ def main():
     for arg in args:
         check(arg)
 
-class NannyNag:
+class NannyNag(Exception):
     def __init__(self, lineno, msg, line):
         self.lineno, self.msg, self.line = lineno, msg, line
     def get_lineno(self):

Lib/xdrlib.py

@@ -13,7 +13,7 @@ except ImportError:
 __all__ = ["Error", "Packer", "Unpacker", "ConversionError"]
 
 # exceptions
-class Error:
+class Error(Exception):
     """Exception class for this module. Use:
 
     except xdrlib.Error, var: