python-requests: POST works, PUT fails - "Authentication credentials were not provided." - django

Question

Editing again with more updates:
Trying to troubleshoot python-requests to see if something is wrong with a PUT request, but not sure how to proceed.
Below is a snippet of my code:
def API_request(url=None, headers=None, payload=None, update=False):
r = None
if update and headers and payload:
print "put request to %s with %s of %s" % (url, headers, payload)
r = requests.put(url, headers=headers, data=payload)
if headers and payload and not update:
print "post request to %s with %s of %s" % (url, headers, payload)
r = requests.post(url, headers=headers, data=payload)
print r.status_code
print r.text
When the above sends a POST request to create a record, it works. However, whenever it sends a PUT request, I get a 401 error: "Authentication credentials were not provided." This happens across multiple endpoints.
401
{"detail":"Authentication credentials were not provided."}
If I copy/paste the relevant printed output from the above PUT print function into a direct HTTPie request, it works. The below request results in a successful 200 response and updated record on the server:
http --debug PUT [url] < [file containing payload] Authorization:'Token [token]'
If I hard code a simple script that does nothing more than import python and json and PUT the exact same data to the same url using the same headers (printed form the original statement), it works. The below script results in a successful 200 response and updated record on the server:
import requests, json
url = "[my url"
headers = {'Content-Type': 'application/json', 'Authorization': 'Token [my token]'}
data = {[my data]}
payload = json.dumps(data)
r = requests.put(url, headers=headers, data=payload)
print r.status_code
print r.text
I've sent the information from both scripts to https://requestbin.fullcontact.com/ and they look to be identical.
BIG ISSUE:
After an entire day of debugging I figured out that even the requests that were generating a 401 error were successfully hitting the server and updating the appropriate records. Put simply, this would not be possible without a correct and functional authentication. Given that, why would I be getting a 401 error from the PUT request?
Happy to answer any questions in comments.

Answer 1

The above was sending a follow-up GET request (without the header, so it was failing) after successfully sending the PUT request (which was succeeding). I caught this by logging all requests hitting the server.
I figured out why the follow up GET was being sent and corrected that. I still don't understand why the r.code and r.text response from the successful PUT was never printing and hitting the console. Had I seen that, it would have been much easier to find. However, since the main problem is resolved, I can't spend time troubleshooting that.
I should have been seeing both responses - the success and the fail in the console - problem for another time.