requests 中间件的写法

test.py

from requests import Session, Response
from requests.adapters import HTTPAdapter


class MiddlewareHTTPAdapter(HTTPAdapter):
    def __init__(self, middlewares=None, *args, **kwargs):
        self.middlewares = middlewares or []
        super().__init__(*args, **kwargs)

    def register(self, middleware):
        self.middlewares.append(middleware)

    def send(self, request, *args, **kwargs):
        for middleware in self.middlewares:
            middleware.before_send(request, **kwargs)

        return super().send(request, *args, **kwargs)

    def build_response(self, req, resp):
        response = super().build_response(req, resp)
        for middleware in reversed(self.middlewares):
            response = middleware.after_build_response(req, resp, response)
        return response


class LoggingMiddleware:
    def before_send(self, request, *args, **kwargs):
        print(f'URL: {request.url}')

    def after_build_response(self, req, resp, response):
        print(f'{response.url}: {response.status_code}')
        return response


if __name__ == '__main__':
    session = Session()
    middlewares = [LoggingMiddleware()]
    adapter = MiddlewareHTTPAdapter(middlewares)
    session.mount('http://', adapter)
    session.mount('https://', adapter)
    session.get('https://www.douban.com')