Invert a dictionaries keys and values

invert_dictionary.py

import json
import os

# Invert a dictionary's keys and values
# USAGE: FILE=myfile.json venv/bin/python invert_dictionary.py

FILE = os.getenv('FILE')


def main():
    with open(FILE, 'r') as dictfile:
        data = dictfile.read()
        json_data = json.loads(data)

    new_dict = {}
    for key, value in json_data.items():
        new_dict.update({value: key})

    print(json.dumps(new_dict, indent=4))


if __name__ == '__main__':
    main()