How to calculate mean value of values on column which go comma?

I have a dataframe:

id   value
a1   1,2
b2   4
c1   NaN
c5   9,10,11

I want to create a new column mean_value which is equal to mean values in column value:

id   value     mean_value
a1   1,2          1.5
b2   4            4
c5   9,10,11      10

and I also want to remove those values in NaN in it. How to do that?

>Solution :

Here’s one way using str.split and mean:

df = df.assign(mean_value=df['value'].str.split(',', expand=True).astype(float)
               .mean(axis=1)).dropna()

Output:

   id    value  mean_value
0  a1      1,2         1.5
1  b2        4         4.0
3  c5  9,10,11        10.0