from ultralytics import YOLO

# Load a model # 三选一
# model = YOLO('yolov8n.yaml')  # build a new model from YAML
# model = YOLO('yolov8n.pt')  # load a pretrained model (recommended for training)
model = YOLO('yolov8n.yaml').load('yolov8n.pt')  # build from YAML and transfer weights

# Train the model
model.train(data='train.yaml', epochs=100, imgsz=640)