bad_asyncio.py

import asyncio
import time

from firebase_admin import db

async def get_hero(key):
    ref = db.reference('heroes').child(key)
    # Calling a blocking method from a coroutine
    return ref.get()

async def get_heroes_range(start, end):
    coroutines = [get_hero('hero_{0}'.format(i)) for i in range(start, end)]
    completed, pending = await asyncio.wait(coroutines)
    for item in completed:
        print(item.result())

t0 = time.time()
event_loop = asyncio.new_event_loop()
try:
    event_loop.run_until_complete(get_heroes_range(0, 100))
finally:
    event_loop.close()
    print('Time elapsed:', (time.time() - t0), 'seconds')
    # Time elapsed: 18.832719087600708 seconds