if the first column is the same and then append the row value together in pandas

The following are the details

Here is the data frame

Name| Filename| delimetier| good delimeter
A     123       48         a
B     123       48         b
C     123       49         c
A     123       48         d
A     123       48         c
B     123       48         d

What I want is

Name| Filename| delimetier| good delimeter
A     123       48         a, c, d
B     123       48         b, d
C     123       49         c

>Solution :

You can use a groupby.apply to achieve this result.

Using this data:

>>> df
  Name  Filename  delimeter good delimeter
0    A       123         48              a
1    B       123         48              b
2    C       123         49              c
3    A       123         48              d
4    A       123         48              c
5    B       123         48              d

Solution

out = (
    df.groupby(['Name', 'Filename', 'delimeter'], as_index=False)
    ['good delimeter'].apply(', '.join)
)

print(out)
  Name  Filename  delimeter good delimeter
0    A       123         48        a, d, c
1    B       123         48           b, d
2    C       123         49              c