使用python -m pip install --upgrade pip升级pip 10.0.1报错：‘NoneType‘ object has no attribute ‘bytes‘

E:\Develop\Python\Pachong> python -m pip install --upgrade pip
Collecting pip
  Using cached https://files.pythonhosted.org/packages/54/eb/4a3642e971f404d69d4f6fa3885559d6756280
1b99d7592487f1ecc4e017/pip-20.3.3-py2.py3-none-any.whl
Installing collected packages: pip
  Found existing installation: pip 10.0.1
    Uninstalling pip-10.0.1:
      Successfully uninstalled pip-10.0.1
  Rolling back uninstall of pip
Exception:
Traceback (most recent call last):
	.
	.
	.
AttributeError: 'NoneType' object has no attribute 'bytes'

错误：
AttributeError: ‘NoneType’ object has no attribute ‘bytes’

python -m pip install --upgrade pip

修改为

easy_install -U pip