In Django, how can I get an exception's message?

ValidationError actually holds multiple error messages.

The output of print err is [u'Empty URL'] because that is the string returned by repr(err.messages) (see ValidationError.__str__ source code).

If you want to print a single readable message out of a ValidationError, you can concatenate the list of error messages, for example:

    # Python 2 
    print '; '.join(err.messages)

    # Python 3
    print('; '.join(err.messages))