pythoncom.CoInitializeEx

CoInitializeEx(flags)

Initialize the COM libraries for the calling thread.

Parameters

flags : int

Flags for the initialization.

Comments

There is no need to call this for the main Python thread, as it is called automatically by pythoncom (using sys.coinit_flags as the param, or COINIT_APARTMENTTHREADED if sys.coinit_flags does not exist).
You must call this manually if you create a thread which wishes to use COM.

Return Value

This function will raise pythoncom.error for all error return values, including RPC_E_CHANGED_MODE error. This is in contrast to pythoncom::CoInitialize which will hide that specific error. If your code is happy to work in a threading model other than the one you specified, you must explicitly handle (and presumably ignore) this exception.