[kovitch]

Solved.

For the record:

# Additional imports
from ctypes import pythonapi, c_void_pointer, py_object

# Setup arguments and return types
pythonapi.PyCObject_AsVoidPtr.restype = c_void_p
pythonapi.PyCObject_AsVoidPtr.argtypes = [ py_object ]

# Convert PyCObject to a void pointer
hWnd = pythonapi.PyCObject_AsVoidPtr( view.winId() )

# Then use hWnd
viz.go( viz.EMBEDDED, window=int( hWnd ) )