How to append to simple JSON object in a file?

Question

My JSON resource is out and I'm trying to fill in the gaps, so bear with me, as I don't quite know the terminology here. I'm working to update the worlds simplest JSON File in Python.

Current a.json :

{"quarters": ["Q2-2019", "Q3-2019", "Q4-2019", "Q1-2020", "Q2-2020", "Q3-2020", "Q4-2020",
              "Q1-2021"]}

I'm looking to append to this, with a result of

{"quarters": ["Q2-2019", "Q3-2019", "Q4-2019", "Q1-2020", "Q2-2020", "Q3-2020", "Q4-2020",
              "Q1-2021", "Q2-2021"]}

I can't seem to find a way to quickly add within the quarters "tag". I've been able to create new "tags", but that's not my intent here.

Answer 1

Use json.load() to parse the JSON into a dictionary. Then just append to the list in the dictionary and write it back out with json.dump

import json

with open('a.json') as f:
    data = json.load(f)
data['quarters'].append('Q2-2021')
with open('a.json', 'w') as f:
    json.dump(f, data)

Answer 2

a["quarters"].append("new_quarter")

should do it. If it isn't in JSON format already:

a = json.loads(a)
a["quarters"].append("new_quarter")