drop duplicated rows and add a count for the repeat count

I would like to add a repeat count for the duplicate rows. current example only drop duplicate rows.

import re
import pandas as pd

data = [
    ['A','B','C'],
    ['A','B','C'],
    ['A','D','C'],
    ['A','D','C']
]

df = pd.DataFrame(data,columns=['x1','x2','x3'])
print(df)

df1 = df.drop_duplicates(keep='first')
print(df1)

expected output:

:   x1 x2 x3
: 0  A  B  C
: 1  A  B  C
: 2  A  D  C
: 3  A  D  C
:   x1 x2 x3 count
: 0  A  B  C 2
: 2  A  D  C 2

>Solution :

Try this line:

df1 = df.groupby(['x1', 'x2', 'x3']).size().reset_index(name='count')

Here, we first group_by x1, x2, and x3, so there will be no duplicates and then count how many duplicates are grouped.