pydata/pandas — pull request #7442 by roblevy (2014-06-12 16:27:55+00:00)
Title: _sanitize_column now reports proper duplicate error

A very simple fix for GH7432. `internals.py` (line 3240) actually raises the correct exception (`ValueError: cannot reindex from a duplicate axis`) but the except: doesn't allow it to be raised. Here I've just allowed the exception itself to be raised since it's more useful to the user than the weird `TypeError` message.