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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 execute(self, commands, pretty_format=False):
 """ Parse and run a DQL string Parameters commands : str The DQL command string pretty_format : bool Pretty-format the return value. (e.g. 4 -> 'Updated 4 items') """

        tree = parser.parseString(commands)
        self.consumed_capacities = []
        self._analyzing = False
        self._query_rate_limit = None
        for statement in tree:
            try:
                result = self._run(statement)
            except ExplainSignal:
                return self._format_explain()
        if pretty_format:
            return self._pretty_format(tree[-1], result)
        return result