! git clone https://github.com/ultralytics/yolov5 # clone %cd yolov5 %pip install -qr requirements.txt --trusted-host mirrors.tuna.tsinghua.edu.cn # install import torch import utils display = utils.notebook_init() # checks #出错原因:git环境变量设置问题 #简便解决办法:在导入包的上方增加以下代码 import os os.environ["GIT_PYTHON_REFRESH"] = "quiet"