通过 FastAPI 中的异步编程增强您的 API 性能

admin数码23/12/2024 10:04:0400

准备构建高性能api？fastapi助您一臂之力！它能打造快速响应、高效处理高负载的api，本文将详解如何利用fastapi的异步编程实现这一目标，并指导您编写和测试异步端点。

学习目标

本文将带您掌握：

异步编程基础及优势。
FastAPI异步开发环境搭建。
异步端点的编写和测试实战。
使用异步库处理HTTP请求、文件及后台任务。

FastAPI异步编程优势

何为异步编程？

异步编程允许任务并发执行，尤其适用于网络请求、数据库查询或文件操作等需要等待响应的任务。

为何重要？

传统同步编程中，任务顺序执行，处理多个请求时容易延时。异步编程则可同时服务多个用户，最大化资源利用率，提升用户体验。

FastAPI环境配置

让我们开始构建！首先，安装所需库：

pip install "fastapi[standard]" httpx aiofiles pytest

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代码示例

以下示例演示FastAPI异步编程：

from fastapi import FastAPI, BackgroundTasks
import httpx
import aiofiles
import pytest
from fastapi.testclient import TestClient

app = FastAPI()

# API端点
@app.get("/item/{item_id}")
async def read_item(item_id: int):
    return {"item_id": item_id}

@app.get("/external-api")
async def call_external_api():
    async with httpx.AsyncClient() as client:
        response = await client.get("https://jsonplaceholder.typicode.com/posts/1")
    return response.json()

@app.get("/read-file")
async def read_file():
    async with aiofiles.open("example.txt", mode="r") as file:
        content = await file.read()
    return {"content": content}

def send_email(email: str, message: str):
    print(f"Sending email to {email}: {message}")

@app.post("/send-email/")
async def schedule_email(background_tasks: BackgroundTasks, email: str):
    background_tasks.add_task(send_email, email, "Welcome!")
    return {"message": "Email scheduled"}

# 测试代码
client = TestClient(app)

def test_read_item():
    response = client.get("/item/1")
    assert response.status_code == 200
    assert response.json() == {"item_id": 1}

def test_read_file():
    with open("example.txt", "w") as file:
        file.write("This is a test file.")
    response = client.get("/read-file")
    assert response.status_code == 200
    assert response.json() == {"content": "This is a test file."}

def test_schedule_email():
    response = client.post("/send-email/?email=test@example.com")
    assert response.status_code == 200
    assert response.json() == {"message": "Email scheduled"}

@pytest.mark.asyncio
async def test_call_external_api():
    async with httpx.AsyncClient() as async_client:
        response = await async_client.get("https://jsonplaceholder.typicode.com/posts/1")
    assert response.status_code == 200
    assert "id" in response.json()

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