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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 validate(self, qstr, editing=True):

 """Validate entered path"""

        if self.selected_text == qstr and qstr != '':
            self.valid.emit(True, True)
            return

        valid = self.is_valid(qstr)
        if editing:
            if valid:
                self.valid.emit(True, False)
            else:
                self.valid.emit(False, False)