python 安装损坏：没有名为 Shutil 的模块

Question

我有 Linux Mint 19.3 Cinnamon，内核 4.15.0-124-generic。

我对Python安装进行了很多尝试和错误，恐怕现在已经搞砸了。 python 和 python3 命令都可以工作（尽管它们指向不同的版本）：

denis@denis-hp ~ $ python
Python 3.7.10 (default, Feb 20 2021, 21:17:23) 
[GCC 7.5.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> 
denis@denis-hp ~ $ python3
Python 3.6.9 (default, Jan 26 2021, 15:33:00) 
[GCC 8.4.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> 

但是一些使用 python 的程序，包括pip（但不包括pip3）会引发以下错误：

denis@denis-hp ~ $ pip
Traceback (most recent call last):
  File "/usr/local/bin/pip", line 5, in <module>
    from pip._internal.cli.main import main
  File "/home/denis/.local/lib/python3.7/site-packages/pip/_internal/cli/main.py", line 10, in <module>
    from pip._internal.cli.autocompletion import autocomplete
  File "/home/denis/.local/lib/python3.7/site-packages/pip/_internal/cli/autocompletion.py", line 9, in <module>
    from pip._internal.cli.main_parser import create_main_parser
  File "/home/denis/.local/lib/python3.7/site-packages/pip/_internal/cli/main_parser.py", line 7, in <module>
    from pip._internal.cli import cmdoptions
  File "/home/denis/.local/lib/python3.7/site-packages/pip/_internal/cli/cmdoptions.py", line 23, in <module>
    from pip._internal.cli.progress_bars import BAR_TYPES
  File "/home/denis/.local/lib/python3.7/site-packages/pip/_internal/cli/progress_bars.py", line 11, in <module>
    from pip._internal.utils.compat import WINDOWS
  File "/home/denis/.local/lib/python3.7/site-packages/pip/_internal/utils/compat.py", line 14, in <module>
    import shutil
ModuleNotFoundError: No module named 'shutil'

在尝试了很多事情并在谷歌上搜索错误但没有成功后，我出于绝望而在这里发帖...提前感谢您的帮助。