How to retain cookies for xmlrpc.client in Python 3?

Question

The default Python xmlrpc.client.Transport (can be used with xmlrpc.client.ServerProxy) does not retain cookies, which are sometimes needed for cookie

Answer 1

Existing answer from GermainZ works only for HTTP. After a lot of time fighting with it, there is HTTPS adaptation. Note the context option which is crucial.

class CookiesTransport(xmlrpc.client.SafeTransport):
    """A SafeTransport (HTTPS) subclass that retains cookies over its lifetime."""

    # Note context option - it's required for success
    def __init__(self, context=None):
        super().__init__(context=context)
        self._cookies = []

    def send_headers(self, connection, headers):
        if self._cookies:
            connection.putheader("Cookie", "; ".join(self._cookies))
        super().send_headers(connection, headers)

    def parse_response(self, response):
        # This check is required if in some responses we receive no cookies at all
        if response.msg.get_all("Set-Cookie"):
            for header in response.msg.get_all("Set-Cookie"):
                cookie = header.split(";", 1)[0]
                self._cookies.append(cookie)
        return super().parse_response(response)

The reason for it is that ServerProxy doesn't respect context option related to transport, if transport is specified, so we need to use it directly in Transport constructor.

Usage:

import xmlrpc.client
import ssl


transport = CookiesTransport(context=ssl._create_unverified_context())
# Note the closing slash in address as well, very important
server = xmlrpc.client.ServerProxy("https://<api_link>/", transport=transport)

# do stuff with server
server.myApiFunc({'param1': 'x', 'param2': 'y'})

Answer 2

This is a simple Transport subclass that will retain all cookies:

class CookiesTransport(xmlrpc.client.Transport):
"""A Transport subclass that retains cookies over its lifetime."""

    def __init__(self):
        super().__init__()
        self._cookies = []

    def send_headers(self, connection, headers):
        if self._cookies:
            connection.putheader("Cookie", "; ".join(self._cookies))
        super().send_headers(connection, headers)

    def parse_response(self, response):
        for header in response.msg.get_all("Set-Cookie"):
            cookie = header.split(";", 1)[0]
            self._cookies.append(cookie)
        return super().parse_response(response)

Usage:

proxy = xmlrpc.client.ServerProxy(URL, CookiesTransport())

Since xmlrpc.client in Python 3 has better suited hooks for this, it's much simpler than an equivalent Python 2 version.