psql_to_json.py

#!/usr/bin/env python3

import asyncio
import asyncpg

#DB_CONFIG = {
#    'host': 'localhost',
#    'user': 'drupal_user',
#    'password': 'password',
#    'port': 5432,
#    'database': 'drupaldb'
#}

async def run():
    conn = await asyncpg.connect(user='drupal_user', password='password',
                                 database='drupaldb', host='127.0.0.1')
    values = await conn.fetch('''COPY (select row_to_json(pg_stat_all_tables) from pg_stat_all_tables) TO '/tmp/out.json';''')
    await conn.close()

    for value in values:
        print(value)

loop = asyncio.get_event_loop()
loop.run_until_complete(run())