How to Handle a 401 Response When Calling SharePoint API with a Token in Python

What will you learn?

  • Learn how to authenticate and call SharePoint API using tokens in Python.
  • Understand how to troubleshoot and handle a 401 unauthorized error effectively.

Introduction to the Problem and Solution

When working with SharePoint APIs, encountering authentication challenges like receiving a 401 response despite providing a valid token is common. In this comprehensive guide, we delve into methods to effectively address this issue. By gaining insights into the root causes of this problem, we can implement suitable solutions for successful API interactions.


# Import necessary libraries
import requests

# Specify your SharePoint API endpoint and access token

# Prepare headers with authorization bearer token
headers = {
    "Authorization": f"Bearer {token}"

# Make a GET request to the SharePoint API endpoint
response = requests.get(url, headers=headers)

# Check if the response is successful or handle errors accordingly
if response.status_code == 200:
    print("Successful API call")
    print(f"Error: {response.status_code}")

# Copyright PHD


In this code snippet: 1. We import the requests library for sending HTTP requests conveniently. 2. Define the target URL of the SharePoint API and provide an access token for authentication. 3. Set up request headers with an authorization bearer token containing our access token. 4. Execute a GET request using requests.get() along with our URL and headers. 5. Verify the status code of the response; success is indicated by 200, else handle errors based on different status codes received.

    Why am I getting a 401 Unauthorized Error from SharePoint API?

    Possible reasons include invalid or expired tokens, incorrect permissions, or misconfigured authentication settings.

    How can I obtain an access token for SharePoint API?

    You can acquire an access token by registering your app in Azure AD, granting necessary permissions, and following OAuth authentication flows.

    Is there any specific format required for setting authorization headers in Python requests?

    Authorization headers should follow the format “Bearer ” for most APIs requiring Bearer Token authentication.

    What other HTTP status codes should I be aware of when working with APIs?

    Common status codes include 404 (Not Found), 500 (Internal Server Error), and 403 (Forbidden) among others.

    Can I use libraries other than requests for making HTTP calls in Python?

    Yes, alternatives like http.client, urllib, or third-party libraries such as httpx can also be used for making HTTP requests in Python.


    By following the outlined steps above, you can efficiently manage scenarios where you encounter a 401 unauthorized error while calling SharePoint APIs using Python scripts. Understanding authentication mechanisms is key to ensuring smooth interactions between your application and external services like Microsoft’s cloud platforms.

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