QComboBox Signals doesn't invoke the called function

[ladiesfinger]

I'm using PyQt .

I had two comboboxes . First combobox has seven commands as text . Each command has its own options . ( i'll put options in the second combobox )

if user clicks commands combobox , then only the second combobox should appear with appropriate options loaded on it.

To do this action , i've tried to connect the 'changing' event with the function that implements the second combobox .

But , the function doesn't get invoked ..... ( i can't figure out what problem is )


i'll paste the code here :

self.connect(self.command,QtCore.SIGNAL('editTextChanged()'),self.optionopen)

self.connect(self.command,QtCore.SIGNAL('editTextChanged()'),self.optionopen)

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called function :

def optionopen(self):
    self.optionlab=QtGui.QLabel('Option:',self)
    self.loc.addWidget(self.optionlab,4,10)
    self.option=QtGui.QComboBox(self)
    self.loc.addWidget(self.option,4,14)
    self.option.insertItems(268,list)
    self.setLayout(self.loc)

def optionopen(self):
    self.optionlab=QtGui.QLabel('Option:',self)
    self.loc.addWidget(self.optionlab,4,10)
    self.option=QtGui.QComboBox(self)
    self.loc.addWidget(self.option,4,14)
    self.option.insertItems(268,list)
    self.setLayout(self.loc)

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I've tried out following functions:

changeEvent()
activated()
currentIndexChanged()
and finally
editTextChanged()

Plz , help me out .....
Any suggestions are welcome....