Python3 Lettuce throws SyntaxError

Unfortunately for you, lettuce is not compatible with Python 3.

The project doesn't state anywhere what they are compatible with, but their source code is using Python 2 specific statements, like the print statement that triggered the exception. There are however more problems than just that print. There is an issue open asking for Python 3 support.

If you must use lettuce then you'll need to use Python 2.7 instead. Otherwise, there appears to be a fork called aloe that works with nose and Python 3.

There is now a fork of lettuce that seems to work on Python 3.

See also the github discussion.