pandas.Series.groupby — pandas 1.3.5 documentation
https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas...pandas.Series.groupby¶ Series. groupby (by = None, axis = 0, level = None, as_index = True, sort = True, group_keys = True, squeeze = NoDefault.no_default, observed = False, dropna = True) [source] ¶ Group Series using a mapper or by a Series of columns. A groupby operation involves some combination of splitting the object, applying a function, and combining the results.