def load_classes(classes_path):
    """
    Loads the classes from file `classes_path`.
    """
    c2i = {}
    i2c = {}

    with open(classes_path, 'r') as cf:
        for line in cf:
            line = line.strip()
            cols = line.split('\t')
            label, id = cols[0], int(cols[1])
            c2i[label] = id
            i2c[id] = label
    return c2i, i2c