How to find count of repeated number in a dataframe?

Question

In above image I want to find the count of a number which is repeated in 'Source' column and also want it'svalue

Expected output:-

Source   Count   Destination 
99        2       [81,230]
2997      4       [153,238,246,338] 
2183      3       [204,266,332]

Answer 1

def gen_df():
    df_str = '''
    Source   Count   Destination 
    99        2       [81,230]
    2997      4       [153,238,246,338] 
    2183      3       [204,266,332]
    '''
    df = pd.read_csv(io.StringIO(df_str.strip()), sep='\s+', index_col=False)
    # df.info()
    df['Destination'] = df['Destination'].map(eval)
    # df
    df_raw = df.explode('Destination')[['Source', 'Destination']].sort_values('Destination')
    df_raw.reset_index(drop=True, inplace=True)
    return df_raw

df_raw = gen_df()
print(df_raw)

#    Source Destination
# 0      99          81
# 1    2997         153
# 2    2183         204
# 3      99         230
# 4    2997         238
# 5    2997         246
# 6    2183         266
# 7    2183         332
# 8    2997         338

df_raw['count'] = 1
dfz = df_raw.groupby('Source').aggregate({'count':'sum', 'Destination': list })
print(dfz.reset_index())

#    Source  count           Destination
# 0      99      2             [81, 230]
# 1    2183      3       [204, 266, 332]
# 2    2997      4  [153, 238, 246, 338]

Answer 2

df.groupby("Source").apply(lambda df: pd.Series({"Count": len(df), 
                                                 "Destination": df["Destination"].values})).reset_index()