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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 _fit(y, classes):
 """Calculate the total sum of squares for a vector y classified into classes Parameters y : array (n,1), variable to be classified classes : array (k,1), integer values denoting class membership """

    tss = 0
    for class_def in classes:
        yc = y[class_def]
        css = yc - yc.mean()
        css *= css
        tss += sum(css)
    return tss