Office365-REST-Python-Client | Microsoft 365 & Microsoft Graph Library for Python | Content Management System library

I am trying to connect to a SharePoint Online site with Azure AD App-Only. I am using Office365-REST-Python-Client v2.3.5 (https://github.com/vgrem/Office365-REST-Python-Client).

I have followed the instructions of the following link to grant access via Azure AD App-Only: https://docs.microsoft.com/en-us/sharepoint/dev/solution-guidance/security-apponly-azuread. API Permission Sites.FullControl.All has been granted to my application via "Application Permissions" in the Microsoft Azure Portal. I have also made sure that admin consent has been granted to the API Permissions.

I am able to successfully access my SharePoint Online root site https://{my_tenant_name}.sharepoint.com and upload files to the document library "Documents" without any problems. But if I try to access another SharePoint Online site, https://{my_tenant_name}.sharepoint.com/sites/test, other than my the root site, I receive the following error:

"AADSTS500011: The resource principal named https://{my_tenant_name}.sharepoint.com/sites/test was not found in the tenant named {tenant_guid}. This can happen if the application has not been installed by the administrator of the tenant or consented to by any user in the tenant. You might have sent your authentication request to the wrong tenant."

I have double-checked the SharePoint Online site url, the tenant guid and API permissions including consent by admin but I am not sure what is causing the error.

Below is my code which can reproduce the problem:

A coworker made a working PowerShell script to retrieve Mailboxes and Groups from Office 365. We have both admin rights on Office 365 = I can get all of these information with a internet browser on EAC. When I'm executing the PowerShell script with my Office 365 credentials, I get the excepted results. It means that I have the rights access and permissions on Exchange.

My need is to create a Python script to do almost the same thing then to create a human-readable Excel Workbook (probably using openpyxl) and send email later. Many of you will ask to me why I don't complete the PowerShell script, the simple answer is that this script will be a little part of a biggest project, written in Python.

Here, the PowerShell script:

I have a list in sharepoint online: ListA

This list has 13 items. I want to add more ,let's say 3 more.

I also have a dataframe with 3 columns: Title, Scientist, ID

I would like to create multiple new items, one for each row, and upload them into the list

The goal of this code is to use Python to read an Excel file from a SharePoint folder using the Office365-REST-Python-Client 2.1.7.post1 module. I have worked with our IT Security Team to get ClientID and Client Secret codes for the authorization token and have verified they are working. But, whenever I attempt to access a given Excel file in a document library folder, I'm getting TypeError: 'NoneType' object is not subscriptable errors.

Here's the code: