Why am I unable to parse JSON data with Python3?

I hava a json file called json.json which has the following data:

[
    {
        "browser": "Mozilla",
        "browser_version": "5.0 (X11)",
        "operating_system": "Linux x86_64",
        "user_agent": "Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:81.0) Gecko/20100101 Firefox/81.0",
        "cookie": "",
        "java_enabled": "function javaEnabled() {    [native code]}",
        "pages_viewed": "3",
        "color_depth": "24",
        "screen_resolution": "1920x1080"
    },
    {
        "browser": "Mozilla",
        "browser_version": "5.0 (X11)",
        "operating_system": "Linux x86_64",
        "user_agent": "Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:81.0) Gecko/20100101 Firefox/81.0",
        "cookie": "",
        "java_enabled": "function javaEnabled() {    [native code]}",
        "pages_viewed": "3",
        "color_depth": "24",
        "screen_resolution": "1920x1080"
    }
]

My python code:

import json

#open and read file
json_file = open('json.json','r')
json_data = json_file.read()

#parse json data
obj = json.loads(json_data)

#print json data
print(str(obj['browser'])) #except to print: Mozilla
print(str(obj['browser_version'])) #except to print: 5.0 (X11)
print(str(obj['operating_system'])) #and so on...
print(str(obj['user_agent']))
print(str(obj['cookie']))
print(str(obj['java_enabled']))
print(str(obj['pages_viewed']))
print(str(obj['color_depth']))
print(str(obj['screen_resolution']))

I am trying to parse the data with python, however when I run the python code, I get the following error:

print(str(obj['browser']))
TypeError: list indices must be integers or slices, not str

My goal is to ONLY print the values of each JSON key.