I have a CSV file consisting of multiple columns. Two of which are protein and organism. They have multiple repeating values.

ID   Protein   Organism            date
12   Prot      Homo sapiens        24-dec
ab1  domain    Mus musculus        12-Apr
14   Prot      Homo sapiens        15-Jun
ijk3 ring      Rattus              25-May
ghl  ring      Homo sapiens        23-Jul
cdk8 Prot      Gallus gallus       18-sep
23bg Prot      Eschereria coli     13-sep

I want to know which protein has the most multiple different values. For example,
in the above table, Prot has the most diverse organisms (Homo sapiens, Gallus, Eschereria). The output should look like this:

ID             Protein   Organism                                        date   count
[12,cdk8,23bg] Prot      [Homo sapiens, Gallus gallus, Eschereria coli]  24-dec  3
[ab1]          domain    [Mus musculus]                                  12-Apr  1
[ijk3, ghl]    ring      [Rattus, Homo sapiens]                          25-May  2

So, basically, I want to know the number of different values in column2(Organism) based on column1 (Protein).

I have tried reading values in a set using Pandas but the Organism column is still having duplicate values. Here is what I have tried.

import pandas as pd
import csv

df = pd.read_csv('prot_info.csv', delimiter = ',')

df_out = df.groupby('Protein').agg(set).reset_index()

df_out.to_csv('test.csv', sep='\t')

>Solution :

Try this :

import pandas as pd
import numpy as np

ujoin = lambda x: list(np.unique(x))

df_out = (df
         .groupby(['Protein'], as_index=False)
         .agg(**{'ID': ('ID', ujoin),
                 'Organism': ('Organism', ujoin),
                 'date': ('date', 'max'),
                 'Count': ('Organism', 'nunique'),
                })
        )

>>> print(df_out)

  Protein                    ID  \
0    Prot  [12, 14, 23bg, cdk8]   
1  domain                 [ab1]   
2    ring           [ghl, ijk3]   

                                         Organism    date  Count  
0  [Eschereria coli, Gallus gallus, Homo sapiens]  24-Dec      3  
1                                  [Mus musculus]  12-Apr      1  
2                          [Homo sapiens, Rattus]  25-May      2 

>>> display(df_out)