Some citations:
As we discussed previously, automation objects are COM objects that expose methods and properties using the IDispatch interface. So how do we use these objects from Python? The win32com.client package contains a number of modules to provide access to automation objects. This package supports both late and early bindings, as we will discuss.
To use an IDispatch-based COM object, use the method win32com.client.Dispatch(). This method takes as its first parameter the ProgID or CLSID of the object you wish to create. If you read the documentation for Microsoft Excel, you'll find the ProgID for Excel is Excel.Application, so to create an object that interfaces to Excel, use the following code:
import win32com.client
xl = win32com.client.Dispatch("Excel.Application")
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The WScript.Shell object provides functions to read system information and environment variables, work with the registry and manage shortcuts. (from: 1 2)