Python 요청으로 원시 HTTP 요청을 인쇄하는 방법은 무엇입니까?

<code class="python">import requests

req = requests.Request('POST','http://stackoverflow.com',headers={'X-Custom':'Test'},data='a=1&b=2')
prepared = req.prepare()

def pretty_print_POST(req):
    print('{}\n{}\r\n{}\r\n\r\n{}'.format(
        '-----------START-----------',
        req.method + ' ' + req.url,
        '\r\n'.join('{}: {}'.format(k, v) for k, v in req.headers.items()),
        req.body,
    ))

pretty_print_POST(prepared)</code>

-----------START-----------
POST http://stackoverflow.com/
Content-Length: 7
X-Custom: Test

a=1&b=2

<code class="python">s = requests.Session()
s.send(prepared)</code>