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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 chi_square_calc(classes, table, TOP, P, POP):
 """ Calculate chi-squared. :param classes: confusion matrix classes :type classes : list :param table: confusion matrix table :type table : dict :param TOP: test outcome positive :type TOP : dict :param P: condition positive :type P : dict :param POP: population :type POP : dict :return: chi-squared as float """

    try:
        result = 0
        for i in classes:
            for index, j in enumerate(classes):
                expected = (TOP[j] * P[i]) / (POP[i])
                result += ((table[i][j] - expected)**2) / expected
        return result
    except Exception:
        return "None"