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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 compile_rules(self):
 """ Compile alert rules @rtype list of Rules """

        output = []
        # validate configuration, skip invalid section
        for key_name, section in self.config.items():
            rule = self.compile_section(section)
            if rule is not None:
                output.append(rule)
        return output