Pandas rolling apply function to entire window dataframe
Not with pd.DataFrame.rolling .... that function is applied iteratively to the columns, taking in a series of floats/NaN, and returning a series of floats/NaN, one-by-one. I think you'll have better luck with your intuition....
def rolling_pipe(dataframe, window, fctn): return pd.Series([dataframe.iloc[i-window: i].pipe(fctn) if i >= window else None for i in range(1, len(dataframe)+1)], index = dataframe.index) df.pipe(rolling_pipe, 3, lambda x: x.shape)