Metadata-Version: 2.1 Name: backcall Version: 0.1.0 Summary: Specifications for callback functions passed in to an API Home-page: https://github.com/takluyver/backcall Author: Thomas Kluyver Author-email: takowl@gmail.com License: BSD Platform: UNKNOWN Classifier: Development Status :: 2 - Pre-Alpha Classifier: Intended Audience :: Developers Classifier: License :: OSI Approved :: BSD License Classifier: Natural Language :: English Classifier: Programming Language :: Python :: 2 Classifier: Programming Language :: Python :: 2.7 Classifier: Programming Language :: Python :: 3 Classifier: Programming Language :: Python :: 3.3 ======== backcall ======== .. image:: https://travis-ci.org/takluyver/backcall.png?branch=master :target: https://travis-ci.org/takluyver/backcall Specifications for callback functions passed in to an API If your code lets other people supply callback functions, it's important to specify the function signature you expect, and check that functions support that. Adding extra parameters later would break other peoples code unless you're careful. backcall provides a way of specifying the callback signature using a prototype function:: from backcall import callback_prototype @callback_prototype def handle_ping(sender, delay=None): # Specify positional parameters without a default, and keyword # parameters with a default. pass def register_ping_handler(callback): # This checks and adapts the function passed in: callback = handle_ping.adapt(callback) ping_callbacks.append(callback) If the callback takes fewer parameters than your prototype, *backcall* will wrap it in a function that discards the extra arguments. If the callback expects more arguments, a TypeError is thrown when it is registered. For more details, see the `docs `_ or the `Demo notebook `_. The tests are run with `pytest `_. In the root directory, execute:: py.test