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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 count_mismatches_before_variant(reference_prefix, cdna_prefix):
 """ Computes the number of mismatching nucleotides between two cDNA sequences before a variant locus. Parameters reference_prefix : str cDNA sequence of a reference transcript before a variant locus cdna_prefix : str cDNA sequence detected from RNAseq before a variant locus """

    if len(reference_prefix) != len(cdna_prefix):
        raise ValueError(
            "Expected reference prefix '%s' to be same length as %s" % (
                reference_prefix, cdna_prefix))
    return sum(xi != yi for (xi, yi) in zip(reference_prefix, cdna_prefix))