[PyQt] Newbie's question about inheritance in QtPy4 classes
hpj at urpla.net
Wed Aug 18 21:11:13 BST 2010
On Wednesday 18 August 2010, 21:15:20 Igor pesando wrote:
> Hi all,
> sorry to bother but I'm learning PyQt4 and designer.
> Playing with the code suggested in some tutorials I came with the code
> below which should NOT work according to my understanding of inheritance
> but it works. The problem is that the class MyForm inherits from
> QMainWindow which does not inherit from QDockWidget even if they both
> inherit from QWidget.
> Therefore QtGui.QDockWidget.__init__(self, parent) should fail but
> everything works fine.
> As a matter of fact I tried a similar construction within plain
> python and I get an error message.
> So the question is why QtGui.QDockWidget.__init__(self, parent) works?
> import sys
> from PyQt4 import QtCore, QtGui
> class MyForm(QtGui.QMainWindow):
> def __init__(self, parent=None):
> QtGui.QDockWidget.__init__(self, parent)
> if __name__ == "__main__":
> app = QtGui.QApplication(sys.argv)
> myapp = MyForm()
This works because both classes inherits QWidget, and you don't try to make
any use from your form. Otherwise you would get you you deserve..
See it as a special case of freedom, that you better avoid ;-).
I can imagine, that it's going to be hairy to catch such faults for sip, aka
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