[python] Pull the value of a specific key from json to make it a list

[
        {
            "A":"C:/user/...",
            "B":2
        },
        {
            "A":"C:/abd/...",
            "B"4
        }
 ]

When the above file is referred to as example.json, I would like to make a list by extracting only the values for key'A'. How can I code in this case? (For example, I didn't write down the path name correctly, but the actual file contains all the data values correctly.)

with open('example.json') as make_json:
       json_data = json.load(make_json)

I read it like this A_value = json_data["A"] causes a TypeError that the index in the list must be integrers, not str.

I'd appreciate your help.