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Unable to find an entry point named 'PyNumber_Divide' when trying to call an overridden division operator #802

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Description

@lostmsu

Environment

  • Pythonnet version: 2.3
  • Python version: 3.6.6
  • Operating System: Windows 10 x64

Details

I was trying to dynamically call overridden division operator:

dynamic tf = Py.Import("tensorflow");
var c = tf.constant(42, tf.float32) / 2;

Traceback:

    System.EntryPointNotFoundException: 'Unable to find an entry point named 'PyNumber_Divide' in DLL 'python36'.'

at Python.Runtime.Runtime.PyNumber_Divide(IntPtr o1, IntPtr o2)
at Python.Runtime.PyObject.TryBinaryOperation(BinaryOperationBinder binder, Object arg, Object& result)
at CallSite.Target(Closure , CallSite , Object , Int32 )
at System.Dynamic.UpdateDelegates.UpdateAndExecute2[T0,T1,TRet](CallSite site, T0 arg0, T1 arg1)

It works for + 2 in place of / 2, but might affect other operators too.

Workaround

The workaround is to do .__div__(2) instead of / 2

Activity

  1. den-run-ai commented on Jan 16, 2019

    @den-run-ai
    Contributor

    @lostmsu there are some other funny things with dynamic - see #86. Can you make sure that this is reproducible without using dynamic in pythonnet?

  2. lostmsu commented on Jan 17, 2019

    @lostmsu
    MemberAuthor

    @denfromufa I don't think #86 is directly related. The fact that PyNumber_Divide wrapper exists already seems to be an issue on its own.
    Existence of #86 just indicates TryBinaryOperation is very incomplete.

  3. den-run-ai commented on Jan 17, 2019

    @den-run-ai
    Contributor
  4. den-run-ai commented on Jan 17, 2019

    @den-run-ai
    Contributor

    @lostmsu the issue is that python 3 does not have this method, it is only in Python 2:

    https://docs.python.org/2/c-api/number.html#c.PyNumber_Divide

    Instead probably this one should be used:

    https://docs.python.org/3/c-api/number.html#c.PyNumber_TrueDivide

    Let me know if you like to submit a PR?

  5. lostmsu commented on Jan 17, 2019

    @lostmsu
    MemberAuthor

    @denfromufa I might get to work on this, but not soon enough :(

  6. filmor commented on Jan 18, 2019

    @filmor
    Member

    Ooh, this is a nasty issue, I'll look into it.

  7. self-assigned this
    on Jan 18, 2019
  8. added this to the 2.4.0 milestone on Jan 18, 2019
  9. added a commit that references this issue on Feb 2, 2019
    f27695b
  10. added a commit that references this issue on Feb 25, 2019
    7bc2495
  11. added a commit that references this issue on Jun 17, 2020
    a98099a
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