ipython/ipython — pull request #1535 by doerwalter (2012-03-30 11:12:08+00:00)
Title: Fix pretty printing dispatch

This patch fixes a problem mentioned here:

http://mail.scipy.org/pipermail/ipython-dev/2012-March/008874.html

Search for the best method to use for pretty printing an object
now no longer prefers any registered printer in type_printers for
the class or any of the base classes over a _repr_pretty_ method
defined in the class or any of its base classes.

Instead the mro is walked, looking for both registered printers
and _repr_pretty_ methods, so that the inheritance hierarchy will
be taken into account.