I am trying to take some working code and change from urlib2 to requests. The original code provides basic login information of username, password and posts the KEY and SECRET in the header of the urllib2 request.  The following code is my attempt to change to using the requests module and gain some functionality for making additional API calls.  I have tried dozens of combinations and all return a code 400.  Apparently, my requests code does not successfully furnish the needed information to return a 200 response and provide the needed authorization token.


## Import needed modules

import urllib2, urllib, base64
import httplib
import requests
import json

## initialize variables

KEY = "7f1xxxx-3xxx-4xxx-9a7f-8be66839dede"
SECRET = "45xxxxxx-45xxx-469a-9ae9-a7927a76cfeb"
userName = "my-email@xxx.com"
passWord = "mypassword"
URL = "https://company.com/auth/token"
token = None
sessionid = None


DATA = urllib.urlencode({"grant_type":"password",
                         "username":userName,
                          "password":passWord})

base64string = base64.encodestring('%s:%s' % (KEY, SECRET)).replace('n', '')
request = urllib2.Request(URL, DATA)
request.add_header("Authorization", "Basic %s" % base64string)
result = urllib2.urlopen(request)
token = result.read()
print token

client = requests.session()

payload = {"grant_type":"password",
           "username":userName,
           "password":passWord,
           "applicationId": KEY
           }

headers = {'content-type':'application/json',
           "grant_type":"password",
           "username":userName,
           "password":passWord,
           'applicationsId': KEY,
           'Authorization': base64string,
           'token': token,
           'sessionid': sessionid
           }

response = client.post(URL, params = payload, headers=headers)
token = response.content
print token
 {"error":"invalid_request"}

print response
 <Response [400]>