Added an else statement to cover all the cases and avoid a UnboundLocalError.
Merge branch 'master' into fix-datasource
Merge branch 'master' into fix-datasource
Removed the redundant exception.
Pep8.
More pep8.
Adding change to CHANGES.txt.
Adding test for new exception behavior.
Merge pull request #169 from enthought/fix-datasource

Fix UnboundLocalError when a datasource of the wrong shape is looked for