filter dataframe after groupby and nunique in pandas

Question

i tried df.groupby(\"item\")[\"variable\"].nunique() and it returns a unique count of every item object.

i want to filter to only return the count of \

Answer 1

When you want the groupby to be mapped to every row of the input, think about transform:

df = df[df.groupby("item")["variable"].transform('nunique') > 3]