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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 get_lookup_value(self, value):
 """ Override this method to convert displayed values to lookup values """

        choices = self._field_choices()
        if choices:
            if isinstance(value, list):
                return [c[0] for c in choices if c[1] in value]
            else:
                for c in choices:
                    if c[1] == value:
                        return c[0]
        return value