Python pyspark GroupBy.size用法及代碼示例

>>> df = ps.DataFrame({'A': [1, 2, 2, 3, 3, 3],
...                    'B': [1, 1, 2, 3, 3, 3]},
...                   columns=['A', 'B'])
>>> df
   A  B
0  1  1
1  2  1
2  2  2
3  3  3
4  3  3
5  3  3

>>> df.groupby('A').size().sort_index()
A
1    1
2    2
3    3
dtype: int64

>>> df.groupby(['A', 'B']).size().sort_index()
A  B
1  1    1
2  1    1
   2    1
3  3    3
dtype: int64

>>> df.B.groupby(df.A).size().sort_index()
A
1    1
2    2
3    3
Name: B, dtype: int64

>>> df.groupby(df.A).B.size().sort_index()
A
1    1
2    2
3    3
Name: B, dtype: int64