__unicode__(self) doesn't get called by logging

Question

Long story short:

# this works as expected:
logging.error(my_object.__unicode__())

# this doesn't:
logging.error(my_object)

Same result with __str__(self). Why?

EDIT: __str__ actually works.

Answer 1

>>> class MyClass(object):
...     def __str__(self):
...         return "foobar"
...
>>> import logging
>>> logging.error(MyClass())
ERROR:root:foobar

Works as expected?!

Answer 2

Logging will call str() (which uses __str__() which falls back to __repr__() when it's not defined). This is because the logging framework is not Unicode safe (i.e. you can get errors when you try to write Unicode to the various logging sinks).