[python-win32] comtypes cryptic error - no attribute '__ctypes_from_outparam__'

[AKHIYAROV, Denis (WGK)]

Hello pywin32 users and developers,

I’m generally pretty happy about using COM through comtypes, but get this cryptic error below.

https://github.com/enthought/comtypes/issues/87
http://stackoverflow.com/questions/32869070/comtypes-com-objects-method-returns-tuple-object-has-no-attribute-ctypes

I'm invoking a method of COM object with string argument using comtypes and method returns (it should return a COM string):

---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-102-009507ff0086> in <module>()
----> 1 obj1=xobjData.GetDataType('string_name')

C:\Python\Python27\lib\site-packages\comtypes\__init__.pyc in call_with_inout(self_, *args, **kw)
    657             # be iterable.
    658             if len(outargs) == 1:  # rescode is not iterable
--> 659                 return rescode.__ctypes_from_outparam__()
    660
    661             rescode = list(rescode)

AttributeError: 'tuple' object has no attribute '__ctypes_from_outparam__'

Seems very cryptic error, any help?
%debug magic shows following:

> c:\python\python27\lib\site-packages\comtypes\__init__.py(659)call_with_inout()
    658             if len(outargs) == 1:  # rescode is not iterable
--> 659                 return rescode.__ctypes_from_outparam__()
    660

ipdb> outargs
{0: VARIANT(vt=0x8, u'string_name')}
ipdb> rescode
(VARIANT(vt=0x8, u'string_name'), u'Long')
ipdb> exit



Denis Tauzikhovich Akhiyarov, Senior Consultant
15115 Park Row - Suite 250
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Denis.Akhiyarov at woodgroupkenny.com<mailto:Denis.Akhiyarov at woodgroupkenny.com>
www.msikenny.com<http://www.msikenny.com/>
www.woodgroupkenny.com<http://www.woodgroupkenny.com/>
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