Two ways:
1. Obtain the cookies object directly, which is suitable for situations that do not need to be encapsulated by yourself
response.cookies
requests.post(.....cookies=cookies)
2. Obtain the sessionid directly, and then encapsulate the cookies object by yourself, which is suitable for situations where you need to modify the cookies object
sessionid = response.cookies["sessionid"]
cookies={"sessionid":sessionid,"xxx":"yyy"}
requests.post(.....cookies=cookies)