Python pandas如何将多行合并为一行？

import pandas as pd

data = {'Name': ['John', 'Alice', 'Bob'],
        'Age': [25, 30, 35],
        'City': ['New York', 'Paris', 'London']}
df = pd.DataFrame(data)

   Name  Age      City
0  John   25  New York
1  Alice  30  Paris
2  Bob    35  London

def merge_rows(rows):
    return ', '.join(rows)

merged_row = df.groupby(level=0).agg({'Name': merge_rows, 'Age': merge_rows, 'City': merge_rows})

         Name      Age                 City
0  John, Alice, Bob  25, 30, 35  New York, Paris, London