[PyQt] BUG: sip instance attribute error: Re: [eric4] python qscintilla traceback with current snapshot also

[Phil Thompson]

On Wed, 2 Feb 2011 22:25:09 +0100, "Hans-Peter Jansen" <hpj at urpla.net>
wrote:
> On Wednesday 02 February 2011, 22:16:46 Phil Thompson wrote:
>> On Wed, 2 Feb 2011 21:33:39 +0100, "Hans-Peter Jansen"
>> <hpj at urpla.net>
>>
>> wrote:
>> > [Oops, sorry, send too fast]
>> >
>> > Dear Phil,
>> >
>> > On Tuesday 01 February 2011, 22:26:43 Hans-Peter Jansen wrote:
>> >> Phil, something is badly broken with the current release and the
>> >> snapshots.
>> >
>> > Here's the essence of the issue:
>> >
>> > class A(object):
>> >     def __init__(self):
>> >         # catch access a non existing attribute
>> >         try:
>> >             print self.a, type(self.a)
>> >         except AttributeError:
>> >             pass
>> >
>> > a = A()
>> >
>> > from PyQt4.Qsci import QsciScintilla
>> >
>> > # derive from a sip wrapped class
>> > class B(QsciScintilla):
>> >     def __init__(self):
>> >         # access a non existing attribute results in:
>> >         # TypeError: 'sip.methoddescriptor' object is not callable
>> >         try:
>> >             print self.b, type(self.b)
>> >         except AttributeError:
>> >             pass
>> >
>> > b = B()
>> >
>> > results in:
>> >
>> > Traceback (most recent call last):
>> >   File "sipinstance.py", line 22, in <module>
>> >     b = B()
>> >   File "sipinstance.py", line 18, in __init__
>> >     print self.b, type(self.b)
>> > TypeError: 'sip.methoddescriptor' object is not callable
>> >
>> > Obviously, accessing non existing attributes in classes wrapped by
>> > sip causes havoc (an unexpected TypeError).
>> >
>> > At least for:
>> > python: 2.6
>> > sip: 4.12.1
>> > qt4: 4.6.3
>> > pyqt4: snapshot-4.8.4-278054fd857c
>> >
>> >
>> > I was able to fix eric with this diff:
>> >
>> > --- QScintilla/Editor.py~       2011-02-02 21:31:20.741149390 +0100
>> > +++ QScintilla/Editor.py        2011-02-02 21:31:30.683988621 +0100
>> > @@ -1258,7 +1258,7 @@ class Editor(QsciScintillaCompat):
>> >          """
>> >          try:
>>
>> self.supportedEols[self.getLineSeparator()].setChecked(True)
>>
>> > -        except AttributeError:
>> > +        except (AttributeError, TypeError):
>> >              pass
>> >
>> >      def __eolChanged(self):
>> >
>> > Note: self.supportedEols doesn't exist, when this method is called
>> > the first
>> > time.
>> >
>> > Guess, it's sip 4.12.2 time ;-)
>> >
>> > Pete
>>
>> If I run the code as above I get a "RuntimeError: underlying
>> C/C++..." as expected. Adding the missing call to
>> QsciScintilla.__init__() (and creating a QApplication at the start)
>> then it runs fine (ie. an AttributeError is raised).
> 
> You mean:
> 
> class A(object):
>     def __init__(self):
>         # catch access a non existing attribute
>         try:
>             print self.a, type(self.a)
>         except AttributeError:
>             pass
> 
> a = A()
> 
> from PyQt4 import QtGui
> from PyQt4.Qsci import QsciScintilla
> 
> app = QtGui.QApplication([])
> 
> # derive from a sip wrapped class
> class B(QsciScintilla):
>     def __init__(self):
>         super(B, self).__init__()
>         # access a non existing attribute results in:
>         # TypeError: 'sip.methoddescriptor' object is not callable
>         try:
>             print self.b, type(self.b)
>         except AttributeError:
>             pass
> 
> b = B()
> 
> 
> but still: 
> 
> Traceback (most recent call last):
>   File "sipinstance.py", line 28, in <module>
>     b = B()
>   File "sipinstance.py", line 24, in __init__
>     print self.b, type(self.b)
> TypeError: 'sip.methoddescriptor' object is not callable
> 
> It might be a Python version issue? (where I'm on 2.6, and you?)

I've tried it with 2.6, 2.7 and 3.2rc2 - works fine.

Phil