Dear Michael, I have done a number of operation in between. Providing that information does not help you How to reset index after grouping and various operations is of interest. How to type in a command to find out its current dataframe? Regards. David
On Friday, 13 May 2016, 20:58, Michael Selik <michael.se...@gmail.com> wrote: Just in case I misunderstood, why don't you make a little example of before and after the grouping? This mailing list does not accept attachments, so you'll have to make do with pasting a few rows of comma-separated or tab-separated values. On Fri, May 13, 2016 at 3:56 PM Michael Selik <michael.se...@gmail.com> wrote: In order to preserve your index after the aggregation, you need to make sure it is considered a data column (via reset_index) and then choose how your aggregation will operate on that column. On Fri, May 13, 2016 at 3:29 PM David Shi <davidg...@yahoo.co.uk> wrote: Hello, Michael, Why reset_index before grouping? Regards. David On Friday, 13 May 2016, 17:57, Michael Selik <michael.se...@gmail.com> wrote: On Fri, May 13, 2016 at 12:27 PM David Shi via Python-list <python-list@python.org> wrote: I lost my indexes after grouping in Pandas. I managed to rest_index and got back the index column. But How can I get back a index row? Was the grouping an aggregation? If so, the original indexes are meaningless. What you could do is reset_index before the grouping and when you aggregate decide how to handle the formerly-known-as-index column (min, max, mean, ?). -- https://mail.python.org/mailman/listinfo/python-list