pandas：删除重复行，同时保留虚拟变量值

我有以下数据框示例：

child_id   feature_1   feature_2   feature_3   feature_4   feature_5
   10          1           0           0          0            0
   10          0           0           1          0            0
   10          0           1           0          0            0
   10          0           0           0          1            0
   20          0           0           0          0            1
   20          1           0           0          0            0
   20          0           1           1          0            0
   20          0           0           0          0            0

但是，我想要这个堆叠的数据框，这样子 ID 就不会重复多次：

child_id   feature_1   feature_2   feature_3   feature_4   feature_5
   10          1           1           1           1           0
   20          1           1           1           0           1

由于每一行都不同，我不能简单地删除重复项。有任何想法吗？非常感谢！

child_id  = [10,10,10,10,20,20,20,20]  
feature_1 = [1,0,0,0,0,1,0,0]  
feature_2 = [0,0,1,0,0,0,1,0]
feature_3 = [0,1,0,0,0,0,1,1]  
feature_4 = [0,0,0,1,0,0,0,0]
feature_5 = [0,0,0,0,1,0,0,0]

import pandas as pd
df = pd.DataFrame(zip(child_id,feature_1,feature_2,feature_3,feature_4,feature_5),columns=['A','B','C','D','E','F'])
df

df.groupby('A').max()

 #10       1    1   1   1   0
 #20       1    1   1   0   1