How to group by with array in Python

I have a dataframe df_my that looks like this

       Rows   Seq    Alg          iMap_x
0      1000   1      Max(1,2)      12
1      1000   2      Min(4)        37
2      1000   3      Max(1,2)      28
3      1000   4      Max(1,2)      18
4      1000   5      Sum()         33
..
134    1000   135    Min(4)        04
135    1000   136    Sum()         11
136    1000   137    Max(1,2)      24

I want to have a new dataframe that group by Alg and have array of iMap_x

so it will look like this

       Alg           iMap_x
0      Max(1,2)      [12,28,18,..,24]
1      Min(4)        [37,..,04]
4      Sum()         [33,..,11]

I know that I can group by and sum or find the average

df_my[["Alg","iMap_x"]].groupby(by="Alg").sum()

but I do not know how to make an array !!

>Solution :

Try:

print(df[["Alg", "iMap_x"]].groupby("Alg").agg(list).reset_index())

Prints:

        Alg            iMap_x
0  Max(1,2)  [12, 28, 18, 24]
1    Min(4)           [37, 4]
2     Sum()          [33, 11]

DataFrame used: