Pepacz Pepacz - 25 days ago 6
Python Question

pandas - number of unique rows occurrences in dataframe

How can I count number of occurrences of each unique row in a

DataFrame
?

df = {'x1': ['A','B','A','A','B','A','A','A'], 'x2': [1,3,2,2,3,1,2,3]}
df = pd.DataFrame(df)

df
x1 x2
0 A 1
1 B 3
2 A 2
3 A 2
4 B 3
5 A 1
6 A 2
7 A 3


And I would like to obtain

x1 x2 count
0 A 1 2
1 A 2 3
2 A 3 1
3 B 3 2

Answer

IIUC you can pass param as_index=False as an arg to groupby:

In [100]:
df.groupby(['x1','x2'], as_index=False).count()

Out[100]:
  x1  x2  count
0  A   1      2
1  A   2      3
2  A   3      1
3  B   3      2