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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_training_coverage(self):
 """ Returns a ratio of classifiers that were able to be trained successfully. """

        total = len(self.training_results)
        i = sum(1 for data in self.training_results.values() if not isinstance(data, basestring))
        return i/float(total)