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 …

Mar 10, 2013 · 71 agg is the same as aggregate. It's callable is passed the columns (Series objects) of the DataFrame, one at a time. You could use idxmax to collect the index labels of …

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?

Sep 19, 2022 · select c.id , c.bereichsname , STRING_AGG(j.oberbereich,',') oberBereiches from stellenangebote_archiv as j join bereiche as c on j.bereich_id = c.id group by c.id, …

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 …

Mar 5, 2013 · The useful thing about Series.mode is that it always returns a Series, making it very compatible with agg and apply, especially when reconstructing the groupby output.

I can't figure out the difference between Pandas .aggregate and .apply functions. Take the following as an example: I load a dataset, do a groupby, define a simple function, and either …

Dec 28, 2017 · df.agg({"one": np.mean}) Looking at the source code, it appears that when you use average it's casting the DataFrame to be a numpy array, and then mean is taking the row …

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