Create new column in dataframe

[snippsat]

import pandas as pd

data = {
    'Date': ['1/12/2002', '1/12/2002', '1/12/2002', '1/12/2002', '1/01/2003', '1/01/2003', '1/01/2003', '1/01/2003', '1/01/2003'],
    'id': [1, 1, 1, 2, 1, 1, 2, 2, 2],
    'class': ['L', 'H', 'L', 'L', 'L', 'H', 'H', 'L', 'L'],
    'amount': [5, 6, 7, 3, 2, 8, 7, 9, 1]
}

df = pd.DataFrame(data)
# Pivot the DataFrame
pivot_df = df.pivot_table(index=['Date', 'id'], columns='class', values='amount', aggfunc='sum', fill_value=0)
pivot_df.columns = [f'{col}_class' for col in pivot_df.columns]
# Reset index to get Date and id back as columns
pivot_df = pivot_df.reset_index()
print(pivot_df)

Output:
        Date  id  H_class  L_class
0  1/01/2003   1        8        2
1  1/01/2003   2        7       10
2  1/12/2002   1        6       12
3  1/12/2002   2        0        3