def count_genres(row_df):
    """
    A trade off degree based in the user genre count

    :param row_df: A user dataframe row based in the genres distribution
    :return: A float that is the trade off degree
    """
    count = 0
    for i, number in row_df.iteritems():
        if number > 0.0:
            count += 1
    return count / len(row_df)