These examples use Python2 syntax.  Due to the change in Python from bytestring str objects
to unicode str objects, 2to3 does not perform an adequate transform of the code.  Examples
can be valid on both Python2.5 and Python3, but such code is less readable than it should be.

As a result, the Python3 examples are kept in a separate repo:

https://github.com/minrk/pyzmq-py3k-examples


The differences are very small, but important.