[PyQt] problem with qthread and signal/slot

[Pradnyesh Sawant]

Hello,
i've written a small code which increments a counter in the backend,
and prints it on the frontend. However, i'm passing a dummy string var
along with it in the signal/slot mechanism. The problem is that from
the 2nd call onwards, the string gets printed, but NOT in the 1st
call. (eg, in the foll code i get:- 1, (2, 'a'), (3, 'a'), ...)
The code is:-
**************************************************
import time
import sys
from PyQt4 import QtGui, QtCore

class Counter(QtCore.QThread):
    def __init__(self):
        QtCore.QThread.__init__(self)
        self.cntr = 0
    def run(self):
        while True:
            self.cntr += 1
            self.emit(QtCore.SIGNAL("showCntr"), (self.cntr, "a"))
            time.sleep(1)
            if self.cntr == 10: break
class Gui(QtGui.QDialog):
    def __init__(self, parent = None):
        QtGui.QDialog.__init__(self, parent)
        frameStyle = QtGui.QFrame.Sunken | QtGui.QFrame.Panel

        self.lCntr = QtGui.QLabel()
        self.lCntr.setFrameStyle(frameStyle)
        loGrd = QtGui.QGridLayout()
        loGrd.addWidget(self.lCntr, 0, 0)
        self.setLayout(loGrd)
        self.setWindowTitle(self.tr("Counter"))
    def showCntr(self, val):
        print val
        self.lCntr.setText(str(val))
if __name__ == "__main__":
    app = QtGui.QApplication(sys.argv)
    dialog = Gui()
    cntr = Counter()
    cntr.start()
    QtCore.QObject.connect(cntr, QtCore.SIGNAL("showCntr"),
            dialog.showCntr, QtCore.Qt.QueuedConnection)
    sys.exit(dialog.exec_())
**************************************************
Also, this is my 1st ever prog with signals/slots across threads; and
am a newbie to python and pyqt. So please be considerate and kind
enough to point out mistakes/better approaches with the above code.

Thanks a lot!
-- 
warm regards,
Pradnyesh Sawant
--
Be yourself, everyone else is taken. --Anon