PERF: support mask in group_last by jbrockmendel · Pull Request #46107 · pandas-dev/pandas (original) (raw)

ser = pd.Series(range(10**5), dtype="Int64")
df = pd.DataFrame({"A": 1, "B": ser})
gb = df.groupby("A")

%timeit gb.last()
726 µs ± 26 µs per loop (mean ± std. dev. of 7 runs, 1000 loops each)  # <- main
527 µs ± 3.88 µs per loop (mean ± std. dev. of 7 runs, 1000 loops each)  # <- PR

Also the xref link doesn't seem to exist.

Fixed.