Urllib3 session (persist settings between requests) - python-requests

Question

I wrote a Python script which makes several https requests one after the other by following redirections (its purpose is to login to AWS Cognito via a load balancer):
import requests
session = requests.session()
response = session.get(
f'https://<initial_url>',
allow_redirects=False,
verify=False,
)
response = session.get(
response.headers["Location"],
allow_redirects=False,
verify=False,
)
response = session.post(
response.headers["Location"],
allow_redirects=False,
verify=False,
data={
"_csrf": session.cookies["XSRF-TOKEN"],
"username": <user>,
"password": <password>,
},
)
This works as expected. I would like to use the urllib3 library instead of requests and I transformed the script as follows:
import urllib3
http = urllib3.PoolManager(cert_reqs="CERT_NONE")
response = session.request(
"GET",
f'https://<initial_url>',
redirect=False,
retries=False,
)
response = session.request(
"GET",
response.headers["Location"],
redirect=False,
retries=False,
)
csrf=<get the XSRF-TOKEN cookie from response.headers["Set-Cookie"]>
fields = {
"_csrf": csrf,
"username": <user>,
"password": <password>,
}
response = session.request(
"POST",
response.headers["Location"],
redirect=False,
retries=False,
fields=fields,
)
The GET requests work and the redirects are as expected, but the POST does not (I get an error from Cognito). Based on the documentation
https://docs.python-requests.org/en/latest/user/quickstart/
and
https://urllib3.readthedocs.io/en/latest/user-guide.html
I understand that the equivalent of requests/data is urllib3/fields, as both are used to form-encode data
In the first version of the code, I created a new requests.session() object before the POST request and used it for that and I got the same error as in the urrlib3 case, which led me to believe that urllib3.PoolManager() does not provide a session like requests.session() and that each request is made separately, which makes the POST request fail. Does anyone know if there is a way to have a session in urrlib3 ? I could not find anything in the documentation