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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _openFile(self):
 """Opens a file dialog and sets a value for the QLineEdit widget. This method is also a `SLOT`. """


        file_types = "Comma Separated Values (*.csv);;Text files (*.txt);;All Files (*)"
        ret = QtGui.QFileDialog.getOpenFileName(self,
                                                self.tr('open file'),
                                                filter=file_types)

        if isinstance(ret, tuple):
            ret = ret[0] #PySide compatibility maybe?

        if ret:
            self._filenameLineEdit.setText(ret)
            self._updateFilename()