def load_txt(label_file):
    """Load bounding boxes data from the given label file.

    Parameters
    label_file: str
        Path to label file.
    
    Returns
    data: list
        List of bounding boxes data.
    """
    data = []
    with open(label_file) as f:
        for line in f:
            row = line.strip().split()
            class_id = int(row[0])
            bboxes = list(map(float, row[1:]))
            data.append((class_id, *bboxes))
    return data