abrightersun.de Unicode __repr__ and __str__ functions that return non-ascii characters result on my IPython installation in a stack trace. Try this:
In [1]: class Foo(object):
...: def __repr__(self):
...: return u"äöü"
...:
In [2]: Foo()
Out[2]: ---------------------------------------------------------------------------
UnicodeEncodeError Traceback (most recent call last)
<ipython-input-2-bbcd91f35259> in <module>()
----> 1 Foo()
... (several lines omitted)
/usr/lib/python2.7/dist-packages/IPython/lib/pretty.pyc in _default_pprint(obj, p, cycle)
478 if getattr(klass, '__repr__', None) not in _baseclass_reprs:
479 # A user-provided repr.
--> 480 p.text(repr(obj))
481 return
482 p.begin_group(1, '<')
UnicodeEncodeError: 'ascii' codec can't encode characters in position 0-2: ordinal not in range(128)
The culprit is the default encoding of the output stream: While sys.stdout.encoding is UTF-8, sys.getdefaultencoding() returns ascii. The solution is to run the following code:
import sys
reload(sys)
sys.setdefaultencoding('utf-8')
Insert this into your ipython_config.py (you may need to create it: ipython profile create) and the error goes away!