from PySide import QtGui, QtCore

m = QtGui.QStandardItemModel()
o = QtCore.QObject()

# from pyside docs: class PySide.QtGui.QCompleter(model[, parent=None])

# Model is not set correctly:
c = QtGui.QCompleter( m, o ) 
print c.model(), c.parent() # None <PySide.QtGui.QStandardItemModel object at 0x191d8c0>

# If parent is kwarg, it throws an exception:
c = QtGui.QCompleter( m, parent = o ) # PySide.QtGui.QCompleter(): got multiple values for keyword argument 'parent'.

# this is currently the only way to do it:
c = QtGui.QCompleter() 
c.setModel(m)
c.setParent(o)
print c.model(), c.parent()