Is there any example code of a cpython (not IronPython) client which can call Windows Communication Foundation (WCF) service?
WCF needs to expose functionality through a communication protocol. I think the most commonly used protocol is probably SOAP over HTTP. Let's assume that's what you're using then.
Take a look at this chapter in Dive Into Python. It will show you how to make SOAP calls.
I know of no unified way of calling a WCF service in Python, regardless of communication protocol.