A quirk of looking up the attribute on the GroupBy object is that you can even call non-aggregators like __iter__ or do silly things like .agg('agg', 'mean'). See similar questions with these tags.

Jun 8, 2012 · df_ret[dcol] = grouped.agg({dcol:min}) return df_ret The function df_wavg() returns a dataframe that's grouped by the "groupby" column, and that returns the sum of the weights for the …

Is there any other manner for expressing the input to agg()? Perhaps a list of tuples [(column, function)] would work better, to allow multiple functions applied to the same column?

Consider a database table holding names, with three rows: Peter Paul Mary Is there an easy way to turn this into a single string of Peter, Paul, Mary?

May 15, 2020 · I would like to calculate, by group, the mean of one column and the weighted mean of another column in a dataset using the .agg() function within pandas. I am aware of a few solutions, …

As @unutbu mentioned, the issue is not with the number of lambda functions but rather with the keys in the dict passed to agg() not being in data as columns. OP seems to have tried using named …

Mar 29, 2023 · 3 As you have seen, STRING_AGG is not allowed when using any kind of grouping set in a GROUP BY. You can hack it as follows

How to sort the aggregate values from STRING_AGG () IN PostgreSQL Asked 11 years, 6 months ago Modified 5 months ago Viewed 260k times

Apr 9, 2019 · Pandas groupby agg - how to get counts? Asked 6 years, 10 months ago Modified 2 years, 10 months ago Viewed 35k times

Jun 24, 2021 · SELECT STRING_AGG(ID) ID, (SELECT Country, City FOR JSON PATH) Json FROM Places GROUP BY Country, City I managed to get a similar result in SQL Server 2016 with the code …