json dump to file

import json

data = {"key": "value"}

with open('data.json', 'w') as jsonfile:
    json.dump(data, jsonfile)

import json
with open('data.json', 'w') as f:
    json.dump(data, f)

import json

data = {}

with open('data.txt', 'w') as outfile:
    json.dump(data, outfile)

On a modern system (i.e. Python 3 and UTF-8 support), you can write a nice file with:

import json
with open('data.json', 'w', encoding='utf-8') as f:
    json.dump(data, f, ensure_ascii=False, indent=4)