Session Key Authentication fails sometimes

[Sravan2]

Apologies if this is in the wrong place. 

Im using the Splunk REST API to connect and run search requests through a Python script. I sadly don't have access to the SDK so I have to use the REST API. The issue I'm running into is that after the initial authentication and login, I get back the session key to use for subsequent API calls. The subsequent API calls have a chance to run into a 401 error more often than not, and my current working solution is to use a while loop to keep sending the information until it works. The code looks like below. I set a delay an API call happens every few seconds, but I can't figure out why it will usually fail, but then randomly choose to work. 

done = False
while not done:
    r = requests.post(host + '/services/search/jobs/', headers={'Authorization':'Splunk %s' %Session_key}, data={'Search':query}, verify=False)
    if r.status+code ==201:
        done = True

[marnall]

Is there any reason why you aren't creating a token from the interface under Settings->Users and Authentication->Tokens, and then using it to call the API? That would be much more reliable than using a single session key.