DataFrame如何才能从只有两列( " from“datetime和" to”datetime)变为只有一列date呢？

import pandas as pd
from datetime import datetime

df = pd.DataFrame({'from': ['2022-01-01 10:00:00', '2022-01-02 12:00:00'],
                   'to': ['2022-01-01 12:00:00', '2022-01-02 14:00:00']})

                  from                   to
0  2022-01-01 10:00:00  2022-01-01 12:00:00
1  2022-01-02 12:00:00  2022-01-02 14:00:00

df['date'] = df.apply(lambda row: datetime.strptime(row['from'], '%Y-%m-%d %H:%M:%S').date(), axis=1)

df = df.drop(['from', 'to'], axis=1)

         date
0  2022-01-01
1  2022-01-02