def refresh(self):
    for key in self._operators.keys():
        if (len(key) == 2):
            self._doubleOperators.append(key)
        elif (len(key) == 3):
            self._tripleOperators.append(key)
def refresh(self):
    for key in self._operators.keys():
        if (len(key) == 2):
            self._doubleOperators.append(key)
        elif (len(key) == 3):
            self._tripleOperators.append(key)