fix getproperty exceptions

[aplavin]

this throws KeyError as before when the attribute isn't there (AttributeError in python)
when the attribute is present, but its computation throws a python exception, this PR rethrows it in julia

fixes #696

[codecov-commenter]

Codecov Report

Merging #997 (d2b9cd0) into master (b27bd5a) will decrease coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #997      +/-   ##
==========================================
- Coverage   68.36%   68.35%   -0.02%     
==========================================
  Files          20       20              
  Lines        2023     2038      +15     
==========================================
+ Hits         1383     1393      +10     
- Misses        640      645       +5     

Flag	Coverage Δ
unittests	68.35% <100.00%> (-0.02%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
src/PyCall.jl	72.18% <100.00%> (+1.49%)	⬆️
src/gui.jl	0.00% <0.00%> (ø)

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[aplavin]

bump

[stevengj]

Looks good, modulo a couple of minor tweaks noted above.

[aplavin]

I also pushed the corresponding setproperty fix, if you know the proper way to check the exception please update it as well! For now, getproperty tests fail with your changes.

[stevengj]

What is e.T that pyisinstance(e.T, @pyglobalobjptr(:PyExc_AttributeError)) fails to give the expected result?

[aplavin]

In the two corresponding cases, it's:

e.T = PyObject <class 'ValueError'>
# and
e.T = PyObject <class 'AttributeError'>

[stevengj]

What does pyisinstance(e.T, @pyglobalobjptr(:PyExc_AttributeError)) return in those cases?

[stevengj]

Oh, I see the problem. e.T is not an instance of AttributeError, it is the type itself. So the correct check is

if PyPtr(e.T) != @pyglobalobjptr(:PyExc_AttributeError)

(The goal here is to avoid the string conversion. Also, checking whether it is actually PyExc_AttributeError, not just named "AttributeError", is in principle more robust.)