def add_ground_truths(classifications_df, cazy_dict):
    """Retrieve ground truth CAZyme/non-CAZyme classifications and add to the df of predictions.

    :param classifications_df: pandas dataframe of prediction tool CAZyme/non-CAZyme classifications
    for each protein. Each unqiue protein is one row, each prediction tool is one column.

    Return df containing the prediction tool predictions and CAZy ground truths added as an
    additional column, called 'CAZy'.
    """
    cazy_c_nc_classification = []
    # tool_predictions = clasifications_df

    protein_accessions = classifications_df.index
    for protein_accession in protein_accessions:
        try:
            cazy_dict[protein_accession]
            cazyme_classification = 1
        except KeyError:
            cazyme_classification = 0

        cazy_c_nc_classification.append(cazyme_classification)

    classifications_df["CAZy"] = cazy_c_nc_classification

    return classifications_df