Is it possible to design interfaces that classes must implement in Python?
There are some well-known 'independent' implementations of interfaces: Zope Interfaces :http://www.zope.org/Wikis/Interfaces/FrontPage - a separable component of the much larger app server Twisted Interfaces: see http://twistedmatrix.com/
PyProtocols: http://peak.telecommunity.com/PyProtocols.html, whose author is one of the protagonists in the PEP246 saga
There are also several possible light-weight roll-your-own solutions One common idiom is an abstract base class:
class SomeInterface(object):
def someMethod(self, argspec):
# Should never get here, because the implementation overrides this
method
raise NotImplmentedErrorbut the compiler doesn't pay any special attention to these classes so failure to implement the interface is detected at runtime
If it's not, is this functionality planned at all for the future?
Python Enhancement Proposals 245, and 246 http://www.python.org/peps/ discuss an interface syntax and the related topic of object adaptation. These are both current discussions among the Python developers with no decision on whether/when to introduce either as far as I know. Observer the fray at: http://mail.python.org/pipermail/python-dev/
Guido Van Rossum (Python creator and BDFL) recently blogged about "Optional Static Type Checking" http://www.artima.com/weblogs/viewpost.jsp?thread=89161
as part of long-range planning for a future Python 3000 (some years in the future)
HTH
Michael
-- http://mail.python.org/mailman/listinfo/python-list
