GroupBy Doesn't Always Maintain Column Index Name (original) (raw)

Just as a follow up to #29124 discovered during #29753 - looks like the column name is dropped for any/all and transformation functions in groupby

df = pd.DataFrame([[1]], columns=pd.Index(["a"], name="idx")) df.groupby([1]).sum() idx a 1 1 df.groupby([1]).any() a 1 True df.groupby([1]).shift() a 0 NaN