pip 安装错误 Command _command

贵有恒，何必三更起、五更眠、最无益，只怕一日曝、十日寒。这篇文章主要讲述pip 安装错误 Command相关的知识，希望能为你提供帮助。
[python2.7版本] pip安装包或者 pip升级pip版本出现此错误：
?

······
File "/tmp/pip-build-vD3Ntt/pip/setup.py", line 7
def read(rel_path: str) -> str:
^
SyntaxError: invalid syntax

----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-build-vD3Ntt/pip/
You are using pip version 8.1.2, however version 21.2.3 is available.
You should consider upgrading via the \'pip install --upgrade pip\' command.

出现此错误后，执行升级pip和setuptools也出同样错误，网上搜索此错误解决方式都是升级pip和setuptools