I am using a possibly non-standard python package called Forthon, and when I inspect an object that is dependent on the Forthon class, I get the following error:

File "/Users/zerbeb/homemade_programs/config2class/src/method_parsing.py", line 18, in get_all_init_args
inherited_classes = inspect.getmro(class_obj)
File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/inspect.py", line 346, in getmro
if hasattr(cls, "__bases__"):
File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/inspect.py", line 337, in _searchbases
for base in cls.__bases__:
AttributeError: 'Forthon' object has no attribute '__bases__'

This was easy enough to fix, simply add "if not hasattr(cls,'__bases__'): return" to the _searchbases function:

def _searchbases(cls, accum):
    # Simulate the "classic class" search order.
    if cls in accum:
        return
    if not hasattr(cls, "__bases__"): #Additional code.
        return
    accum.append(cls)
    for base in cls.__bases__:
        _searchbases(base, accum)

Maybe you have a better solution, but I think this edge case can be trivially solved however you decide to edit the code.

Thanks!

Which version of python are you running? I can't match that traceback up to the code in the current 2.7 inspect module.

That said, the same issue probably exists in the current code. A 2.7 class is expected to have either an __mro__ or a __bases__ attribute, and if it has neither inspect probably *should* throw an error, since it can't know what to do with the class. The error could be clearer, though.

But, let's see what others think.

I am using Python 2.7.5.  The segment of code from inspect that I previously extracted came from line 332 although you may also find it by "finding" _searchbases.

This is really an issue with Forthon:

http://hifweb.lbl.gov/Forthon/

Specifically the Forthon class, which I think is older than current standards.  If you guys want this Forthon class to flag an error (I can work around that too), than the proposed fix I sent can be rejected, and this ticket can be closed.  I just wanted to bring this case to you attention just in case.

Thanks again,

Brandon

Quoting "R. David Murray" <report@bugs.python.org>:

R. David Murray added the comment:

Which version of python are you running?  I can't match that
traceback up to the code in the current 2.7 inspect module.

That said, the same issue probably exists in the current code.  A 2.7
class is expected to have either an __mro__ or a __bases__ attribute,
and if it has neither inspect probably *should* throw an error, since
it can't know what to do with the class.  The error could be clearer,
though.

But, let's see what others think.

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nosy: +r.david.murray

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Python tracker <report@bugs.python.org>
<http://bugs.python.org/issue25884\>

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The _searchbases function was removed here, when getmro was simplified following the removal of old style classes:

b82c8e5