Updating Key in JSON File

[Larz60+]

I added code to print out dictionary before and after changes, also cleaned up code a bit
** Note ** Uses f-string which requires python 3.6 or newer

import json
import os


def replace_acls(self, filename, dn, role):
    with open(filename, 'r') as f:
        dn = f.read().replace(role, dn)
 
    with open(filename, 'w') as f:
        f.write(dn)

def display_dict(dictname, level=0):
    '''
    Display formatted dictionary 
    '''
    indent = " " * (4 * level)
    for key, value in dictname.items():
        if isinstance(value, dict):
            print(f'\n{indent}{key}')
            level += 1
            display_dict(value, level)
        else:
            print(f'{indent}{key}: {value}')
        if level > 0:
            level -= 1

def main():
    # anchor starting directory
    os.chdir(os.path.abspath(os.path.dirname(__file__)))

    with open('acl.json', 'r') as f:
        data = json.load(f)
    
    print(f'\nDictionary before modification', end='')
    display_dict(data)

    data['roles']['Deployer'] = ['CN=Dev_Deployer','OU=test','DC=example','DC=com']

    print(f'\nDictionary after modification', end='')
    display_dict(data)

    with open('acl.json', 'w') as f:
        json.dump(data, f, indent=2)

if __name__ == '__main__':
    main()

Output:

Output:
Dictionary before modification
operations

    ops_modify
        paths: ['ops_set_config']
        methods: ['GET']

    ops_read
        paths: ['ops_get_summary', 'ops_get_request_info']
        methods: ['GET']

roles
    Server Op: ['emc', 'mgmt', 'fips_read']
    Deployer: ['mgmt', 'config']
    KP Admin: ['mgmt', 'kp']

permissions
    logs: ['ops_read', 'file']
    adminusers: ['adminusers.read']

Dictionary after modification
operations

    ops_modify
        paths: ['ops_set_config']
        methods: ['GET']

    ops_read
        paths: ['ops_get_summary', 'ops_get_request_info']
        methods: ['GET']

roles
    Server Op: ['emc', 'mgmt', 'fips_read']
    Deployer: ['CN=Dev_Deployer', 'OU=test', 'DC=example', 'DC=com']
    KP Admin: ['mgmt', 'kp']

permissions
    logs: ['ops_read', 'file']
    adminusers: ['adminusers.read']