问如何让熊猫显示所有的最大值？

EN

df_max = df.loc[df.groupby('date')['quantity'].transform('max') ==df['quantity'] ]

import pandas as pd
df = pd.DataFrame({"date":['2021-01-01','2021-01-01','2021-01-01','2021-01-01',
                        '2021-01-02','2021-01-02','2021-01-03','2021-01-03'],  
                   "quantity":[11, 2, 5, 8, 11, 8, 11, 4]})
print (df)

dfmax = df.loc[df.groupby('date')['quantity'].idxmax()]

print (dfmax)

         date  quantity
0  2021-01-01        11
1  2021-01-01         2
2  2021-01-01         5
3  2021-01-01         8
4  2021-01-02        11
5  2021-01-02         8
6  2021-01-03        11
7  2021-01-03         4

         date  quantity
0  2021-01-01        11
4  2021-01-02        11
6  2021-01-03        11

dfmax = df[df.groupby('date')['quantity'].apply(lambda x: x==x.max())]