ContinuumIO/blaze — pull request #459 by mrocklin (2014-08-12 15:32:07+00:00)
Title: pandas: enforce expression column names on `by`

Pandas and Blaze differ as to column names coming off of a split-apply-combine operation. This pull request renames the dataframe with the expression's columns to maintain consistency.

This renaming exposes a previously occuring error.