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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 crps(self):
 """ Calculates the continuous ranked probability score. """

        return np.sum(self.errors["F_2"].values - self.errors["F_O"].values * 2.0 + self.errors["O_2"].values) / \
            (self.thresholds.size * self.num_forecasts)