pydata/pandas — pull request #4549 by bburan-galenea (2013-08-13 12:49:27+00:00)
Title: ENH: Keep original traceback in DataFrame.apply

When "raise " is used inside a try/except block, the
original stacktrace (containing the code path that raised the original
exception). This makes debugging difficult since all we know is that an error
occured when `frame._apply_standard` attempted to call the provided function.
Preserve the original stacktrace by using "raise" instead of "raise ". This facilitates debugginb by allowing us to see where (in the
provided callable) the exception occured.