Simple proxy decorator in Python (with Flask and Requests)

proxy.py

import requests

from flask import Flask, request, Response, make_response


app = Flask(__name__)

DESTINATION_URL = 'http://any-external-service/'

def proxy_1(view_function):
  def wrapper(path):
    request_method = getattr(requests, request.method.lower())
    return request_method(f'{DESTINATION_URL}/{path}').content

  return wrapper

def proxy_2(view_function):
  def wrapper(path):
    request_method = getattr(requests, request.method.lower())
    response = request_method(f'{DESTINATION_URL}/{path}',
      data=request.form or request.json or request.data,
      headers=request.headers,
    )
    return response.content, response.status_code, response.headers.items()

  return wrapper

def proxy_2_1(view_function):
  def wrapper(path):
    request_method = getattr(requests, request.method.lower())
    response = clean_hop_by_hop_headers(
      request_method(f'{DESTINATION_URL}/{path}',
        data=request.form or request.json or request.data,
        headers=request.headers,
      )
    )
    return response.content, response.status_code, response.headers.items()

  return wrapper

def proxy_3(view_function):
  def wrapper(path):
    request_method = getattr(requests, request.method.lower())
    raw_response = clean_hop_by_hop_headers(
      request_method(f'{DESTINATION_URL}/{path}',
        data=request.form or request.json or request.data,
        headers=request.headers,
      ),
    )
    processed_response = view_function(raw_response)
    if isinstance(processed_response, Response):
      return processed_response
    return requests_to_flask_response(raw_response)

  return wrapper

def proxy_4(proxy_path=''):
  def real_proxy(view_function):
    def wrapper(path):
      final_path = proxy_path if proxy_path != '' else path
      request_method = getattr(requests, request.method.lower())
      raw_response = clean_hop_by_hop_headers(
        request_method(f'{DESTINATION_URL}/{final_path}',
          data=request.form or request.json or request.data,
          headers=request.headers,
        ),
      )
      processed_response = view_function(raw_response)
      if isinstance(processed_response, Response):
        return processed_response
      return requests_to_flask_response(raw_response)
    return wrapper

  return real_proxy

def clean_hop_by_hop_headers(response):
  hop_by_hop_headers = [
    'Connection', 'Keep-Alive', 'TE', 'Trailer', 'Transfer-Encoding', 'Upgrade',
    'Proxy-Authorization', 'Proxy-Authenticate'
  ]
  for header in hop_by_hop_headers:
    if header in response.headers:
      del response.headers[header]
  return response

def requests_to_flask_response(response):
  return response.content, response.status_code, response.headers.items()

@app.route('/<path:path>', methods=['GET', 'POST', 'PUT', 'DELETE'])
@proxy_4(proxy_path='/api')
def test_view(proxied_response):
  response = make_response({
    'status_message': proxied_response.json()['status']
  })
  response.status_code = 200
  response.headers = { **proxied_response.headers, 'x-foo': 'bar' }.items()
  return response