requests is a synchronous library. You need to use an asyncio-based library to make requests asynchronously.
httpx
httpx is typically used in FastAPI applications to request external services. It provides synchronous and asynchronous clients which can be used in def and async def path operations appropriately. It is also recommended for asynchronous tests of application. I would advice using it by default.
from fastapi import FastAPI
from time import time
import httpx
import asyncio
app = FastAPI()
URL = "http://httpbin.org/uuid"
async def request(client):
response = await client.get(URL)
return response.text
async def task():
async with httpx.AsyncClient() as client:
tasks = [request(client) for i in range(100)]
result = await asyncio.gather(*tasks)
print(result)
@app.get("https://stackoverflow.com/")
async def f():
start = time()
await task()
print("time: ", time() - start)
Output
['{\n "uuid": "65c454bf-9b12-4ba8-98e1-de636bffeed3"\n}\n', '{\n "uuid": "03a48e56-2a44-48e3-bd43-a0b605bef359"\n}\n',...
time: 0.5911855697631836
aiohttp
aiohttp can also be used in FastAPI applications, if you prefer one.
from fastapi import FastAPI
from time import time
import aiohttp
import asyncio
app = FastAPI()
URL = "http://httpbin.org/uuid"
async def request(session):
async with session.get(URL) as response:
return await response.text()
async def task():
async with aiohttp.ClientSession() as session:
tasks = [request(session) for i in range(100)]
result = await asyncio.gather(*tasks)
print(result)
@app.get("https://stackoverflow.com/")
async def f():
start = time()
await task()
print("time: ", time() - start)
If you want to limit the number of requests executing in parallel, you can use asyncio.semaphore like so:
MAX_IN_PARALLEL = 10
limit_sem = asyncio.Semaphore(MAX_IN_PARALLEL)
async def request(client):
async with limit_sem:
response = await client.get(URL)
return response.text