client.py

import asyncio
import httpx
import time

async def get_data_api(city):
    url = f'http://127.0.0.1:8000/api/weather/{city}'

    for i in range(6):
        async with httpx.AsyncClient() as client:
            response = await client.get(url)
            response.raise_for_status()

        data = response.json()
        print('city: {}, temperature: {}, source: {}'.format(
            data.get('city'), data.get('temperature'), data.get('source')))

tasks = [
    asyncio.ensure_future(get_data_api('moskva')),
    asyncio.ensure_future(get_data_api('tokyo')),
    asyncio.ensure_future(get_data_api('london'))
]

start = time.time()

loop = asyncio.get_event_loop()
loop.run_until_complete(asyncio.gather(*tasks))
loop.close()

end = time.time() - start
print(f'time {end:0.2f} seconds')
print(f'mean time for 1 request: {end/18:0.2f} seconds')