pandas.core.groupby.SeriesGroupBy.size#
- SeriesGroupBy.size()[source]#
Compute group sizes.
- Returns:
- DataFrame or Series
Number of rows in each group as a Series if as_index is True or a DataFrame if as_index is False.
See also
Series.groupby
Apply a function groupby to a Series.
DataFrame.groupby
Apply a function groupby to each row or column of a DataFrame.
Examples
For SeriesGroupBy:
>>> lst = ['a', 'a', 'b'] >>> ser = pd.Series([1, 2, 3], index=lst) >>> ser a 1 a 2 b 3 dtype: int64 >>> ser.groupby(level=0).size() a 2 b 1 dtype: int64
>>> data = [[1, 2, 3], [1, 5, 6], [7, 8, 9]] >>> df = pd.DataFrame(data, columns=["a", "b", "c"], ... index=["owl", "toucan", "eagle"]) >>> df a b c owl 1 2 3 toucan 1 5 6 eagle 7 8 9 >>> df.groupby("a").size() a 1 2 7 1 dtype: int64
For Resampler:
>>> ser = pd.Series([1, 2, 3], index=pd.DatetimeIndex( ... ['2023-01-01', '2023-01-15', '2023-02-01'])) >>> ser 2023-01-01 1 2023-01-15 2 2023-02-01 3 dtype: int64 >>> ser.resample('MS').size() 2023-01-01 2 2023-02-01 1 Freq: MS, dtype: int64