Retain strings in a column using a dictionary’s value

I want to retain the string with the largest value based on a dictionary’s key and value. Any suggestion to how to do it effectively?

fruit_dict = {
  "Apple": 10,
  "Watermelon": 20,
  "Cherry": 30
}

df = pd.DataFrame(
    {
        "ID": [1, 2, 3, 4, 5],
        "name": [
            "Apple, Watermelon",
            "Cherry, Watermelon",
            "Apple",
            "Cherry, Apple",
            "Cherry",
        ],
    }
)

   ID                name
0   1   Apple, Watermelon
1   2  Cherry, Watermelon
2   3               Apple
3   4       Cherry, Apple
4   5              Cherry

Expected output:

   ID        name
0   1  Watermelon
1   2      Cherry
2   3       Apple
3   4      Cherry
4   5      Cherry

Answer

One way it to use apply with max and fruit_dict.get as key:

new_df = (df.assign(name=df['name'].str.split(', ')
            .apply(lambda l: max(l, key=fruit_dict.get)))
          )

or, if you expect some names to be missing from the dictionary:

new_df = (df.assign(name=df['name'].str.split(', ')
            .apply(lambda l: max(l, key=lambda x: fruit_dict.get(x, float('-inf'))))
          )

output:

   ID        name
0   1  Watermelon
1   2      Cherry
2   3       Apple
3   4      Cherry
4   5      Cherry