BUG: Look up the _repr_pretty_ method on the class within the MRO rath...

[rkern]

...er than the original leaf class.

Thanks, @doerwalter for finding this and suggesting the fix.

fixes #2122

[bfroehle]

Bah, didn't mean to accidentally close this PR. Reopening.

I'm a little curious why we don't just check for _repr_pretty_ on the actual object itself at the beginning of the method. I assume that it is so that the dispatch order can be more flexible:

• Derived registered printer
• Derived _repr_pretty_
• Base registered printer
• Base _repr_pretty_

However this does preclude adding _repr_pretty_ directly to the object as in

from __future__ import print_function

class A(object):
    _repr_pretty_ = None

a = A()
a._repr_pretty_ = lambda obj, p, cycle: print("A()")

All of this is surely outside the scope of the pull request (and original issue), but it is something to think about.

[bfroehle]

Looks good, thanks for the tests, too!