Dealing with multiple context managers

[heras]

Hi,

How do you structure code around multiple context managers? I looking to make something like this:

#main.py
import file_io.py
import rest_api.py
main():
    main program flow here
    read something from a log file
    GET something from a REST API
    write it to the log file
    POST something to the REST API

#file_io.py
#maybe this could be a class
def read():
    with open('log.txt') as log_file:
        read last entry in log_file
        return entry

def write(something):
    with open('log.txt') as log_file:
        write something to log_file

#rest_api.py
#maybe this could be a class too
token = 'super secret'
header = {"Authorization":"Bearer {}".format(token)}
url = 'api.some_site/endpoint'

with requests.Session() as rest_session:
    rest_session.headers.update(headers)
    GET/PUT/POST stuff depending on main()
    return data to main

I can live with opening and closing a file all the time for every operation, but can I avoid stuffing all my main() logic in the API context manager? Maybe at some point there will be another website with a different API that the program also needs to work with. Or is this a case where you wouldn't wrap the requests.Session() in a context manager and pass the session object around as needed while making sure you catch all exception? Sorry if this is a bit fuzzy. Please let me know if you need more clarification.