ModulNotFoundError matplotlib

[WicardBohnam]

You have two Python versions on your Pc.
This on mean that you have installed a Microsoft python 3.12 app version :

Requirement already satisfied: matplotlib in c:\users\richb\appdata\local\packages\pythonsoftwarefoundation.python.3.12_qbz5n2kfra8p0\localcache\local-packages\python312\site-packages (3.8.4)

Your first error message mean that you also have version from Python.org Python 3.12.2

  File "C:\Users\richb\AppData\Local\Programs\Python\Python312\Lib\idlelib\scatter_plot.py", line 1, in <module>
    import matplotlib.pyplot as plt
ModuleNotFoundError: No module named 'matplotlib

No problem to have several version Python,i have lot more.
Just that have you to choose right Python interpreter from Editor/Ide you run code from.
If this confusing for you,i would go with version from Python.org and uninstall the Microsoft python 3.1 2 app version.

Yeah, that was it, thanks so much. Deleted both versions, reinstalled Python from the Python.org, reinstalled pip and matplotlib.