[PyKDE] qApp is a QApplication instance

Giovanni Bajo rasky at develer.com
Mon Mar 21 16:01:32 GMT 2005

Phil Thompson <phil at riverbankcomputing.co.uk> wrote:

>>>>> sys.modules['qt'].__dict__['qApp'] = A(sys.argv)
>>>>> ...might do it. You have to make sure that this is done before the
>>>>> other
>>>>> modules that want to use it get imported.

>> Well, I'm trying, but it's almost impossible to do it. By the time the
>> constructor has executed, many modules are imported already. Even putting
>> the sys.modules line at the top of A's constructor is not enough because
>> of
>> the fact that many modules are already imported. I even tried reload the
>> modules but that caused other problems.
>> I understand that you consider this not stricly a bug. But there *is* a
>> need
>> to access the application from everywhere without passing it around, and
>> qApp exists exactly for that. In C++, you can downcast it to whatever app
>> type you defined and use it. This is impossible with PyQt.
> No it isn't - sip.cast()

What would the correct syntax would be, then?

def pyApp():
    import sip
    return sip.cast(qApp, App)

gives me a:

SystemError: error return without exception set

Giovanni Bajo

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