升级pip,使用阿里镜像源
python.exe -m pip install --upgrade pip -i https://mirrors.aliyun.com/pypi/simple/
升级flake8
python.exe -m pip install -U flake8 --user -i https://mirrors.aliyun.com/pypi/simple/
python.exe -m pip install --upgrade pip -i https://mirrors.aliyun.com/pypi/simple/
python.exe -m pip install -U flake8 --user -i https://mirrors.aliyun.com/pypi/simple/