三周精通FastAPI：37 包含 WSGI - Flask，Django，Pyramid 以及其它

官方文档：https://fastapi.tiangolo.com/zh/advanced/wsgi/

包含 WSGI - Flask，Django，其它¶

您可以挂载多个 WSGI 应用，正如您在 Sub Applications - Mounts, Behind a Proxy 中所看到的那样。

为此, 您可以使用 WSGIMiddleware 来包装你的 WSGI 应用，如：Flask，Django，等等。

使用 WSGIMiddleware¶

您需要导入 WSGIMiddleware。

然后使用该中间件包装 WSGI 应用（例如 Flask）。

之后将其挂载到某一个路径下。

from fastapi import FastAPI from fastapi.middleware.wsgi import WSGIMiddleware from flask import Flask, request from markupsafe import escape flask_app = Flask(__name__) @flask_app.route("/") def flask_main(): name = request.args.get("name", "World") return f"Hello, {escape(name)} from Flask!" app = FastAPI() @app.get("/v2") def read_main(): return {"message": "Hello World"} app.mount("/v1", WSGIMiddleware(flask_app))

检查¶

现在，所有定义在 /v1/ 路径下的请求将会被 Flask 应用处理。

其余的请求则会被 FastAPI 处理。

如果您使用 Uvicorn 运行应用实例并且访问 http://localhost:8000/v1/，您将会看到由 Flask 返回的响应：

Hello, World from Flask! 

并且如果您访问 http://localhost:8000/v2，您将会看到由 FastAPI 返回的响应：

{ "message": "Hello World" } 

实践

使用中间件来挂载pyramid web应用

示例1

源代码

源文件存盘为fastapipyramid.py文件

from fastapi import FastAPI
from fastapi.middleware.wsgi import WSGIMiddleware
from pyramid.config import Configurator
from pyramid.response import Response


def pyramid_app(environ, start_response):
    config = Configurator()
    def hello_world(request):
        return Response('Hello from Pyramid!')
    config.add_route('hello', '/')
    config.add_view(hello_world, route_name='hello')
    app = config.make_wsgi_app()
    return app(environ, start_response)


app = FastAPI()
app.mount("/pyramid", WSGIMiddleware(pyramid_app))


@app.get("/")
async def read_main():
    return {"message": "Hello from FastAPI"}


if __name__ == "__main__":
    import uvicorn
    uvicorn.run(app, host="0.0.0.0", port=8000)

启动服务

uvicorn fastapipyramid:app --reload

测试

curl 127.0.0.1:8000
{"message":"Hello from FastAPI"}

curl 127.0.0.1:8000/pyramid/
Hello from Pyramid!

示例2

源代码

存为文件pyramid_fastapi.py

from fastapi import FastAPI, Request
from fastapi.middleware.wsgi import WSGIMiddleware
from pyramid_app import create_app  # 导入 Pyramid 应用

# 创建 FastAPI 应用
app = FastAPI()

# 创建 Pyramid WSGI 应用
pyramid_app = create_app()

# 使用 WSGIMiddleware 将 Pyramid 应用包装到 FastAPI 中
app.mount("/pyramid", WSGIMiddleware(pyramid_app))

# 你也可以在 FastAPI 中定义其他路由
@app.get("/fastapi")
def read_root():
    return {"message": "Hello from FastAPI!"}

启动服务：

uvicorn pyramid_fastapi:app --reload

测试

curl 127.0.0.1:8000/fastapi
{"message":"Hello from FastAPI!"}

curl 127.0.0.1:8000/pyramid/
Hello from Pyramid!

调试

启动pyramid报错

from backports import tarfile

ImportError: cannot import name 'tarfile' from 'backports' (/Users/skywalk/py311/lib/python3.11/site-packages/backports/init.py)

python pyramid_app.py
Traceback (most recent call last):
  File "/Users/skywalk/work/fastapi/pyramid_app.py", line 3, in <module>
    from pyramid.config import Configurator
  File "/Users/skywalk/py311/lib/python3.11/site-packages/pyramid/config/__init__.py", line 8, in <module>
    from pyramid.asset import resolve_asset_spec
  File "/Users/skywalk/py311/lib/python3.11/site-packages/pyramid/asset.py", line 2, in <module>
    import pkg_resources
  File "/Users/skywalk/py311/lib/python3.11/site-packages/pkg_resources/__init__.py", line 96, in <module>
    from jaraco.text import (
  File "/Users/skywalk/py311/lib/python3.11/site-packages/setuptools/_vendor/jaraco/text/__init__.py", line 12, in <module>
    from jaraco.context import ExceptionTrap
  File "/Users/skywalk/py311/lib/python3.11/site-packages/setuptools/_vendor/jaraco/context.py", line 17, in <module>
    from backports import tarfile
ImportError: cannot import name 'tarfile' from 'backports' (/Users/skywalk/py311/lib/python3.11/site-packages/backports/__init__.py)

pip安装包解决

pip install jaraco.context