after groupby how to add values in two rows to a list

In [1]: df = pd.DataFrame( {‘a’:[‘A’,’A’,’B’,’B’,’B’,’C’], ‘b’:[1,2,5,5,4,6]})<br /> df</p> <p>Out[1]:<br /> a b<br /> 0 A 1<br /> 1 A 2<br /> 2 B 5<br /> 3 B 5<br /> 4 B 4<br /> 5 C 6</p> <p>In [2]: df.groupby(‘a’)[‘b’].apply(list)<br /> Out[2]:<br /> a<br /> A [1, 2]<br /> B [5, 5, 4]<br /> C [6]<br /> Name: b, dtype: object</p> <p>In [3]: df1 = df.groupby(‘a’)[‘b’].apply(list).reset_index(name=”new”)<br /> df1<br /> Out[3]:<br /> a new<br /> 0 A [1, 2]<br /> 1 B [5, 5, 4]<br /> 2 C [6]