yolov8 运行报错 RuntimeError: An attempt has been made to start a new process before the

yolov8 RuntimeError:          
An attempt has been made to start a new process before the         
current process has finished its bootstrapping phase.          
This probably means that you are not using fork to start your         
child processes and you have forgotten to use the proper idiom         
in the main module:              
if __name__ == '__main__':                 
freeze_support()               
  ...         
 The "freeze_support()" line can be omitted if the program is not going to be frozen to produce an executable.

解决办法：

添加

if __name__ == '__main__':

即

from ultralytics import YOLO

# 加载模型
model = YOLO("yolov8n.yaml")  # 从头开始构建新模型
# model = YOLO("weights/yolov8n.pt")  # 加载预训练模型（推荐用于训练）

# Use the model
# results = model.train(data="ultralytics/datasets/rain.yaml", epochs=20, batch=-1)  # 训练模型
if __name__ == '__main__':
    # Use the model
    results = model.train(data="ultralytics/datasets/rain.yaml", epochs=150, batch=32)  # 训练模型
    results = model.val()  
    results = model("自己的验证图片")  
    success = YOLO("yolov8n.pt").export(format="onnx")