I totally agree this should be fixed (there was a similar issue for psutil: http://code.google.com/p/psutil/issues/detail?id=58) but communicate() and wait() should be affected in the same manner.

Probably it would make sense to add an is_running() method and decorate send_signal(), kill(), communicate() and wait() methods with a function which makes sure that the process is still running, otherwise raises an exception instead.

Maybe it would also makes sense to provide a brand new NoSuchProcess exception class.