我正在使用 python3.9 附带的 Debian 11。但是我不需要，我需要python3.7。所以，我安装了 pythonn3.7.9 并更新了替代品。
问题是当我将 python 版本切换到 3.7.9 时，我无法使用 pip 安装任何东西。pip install我在命令中收到以下错误：
sudo pip3 install requests
[sudo] password for deby:
Traceback (most recent call last):
File "/usr/bin/pip3", line 10, in <module>
from importlib.metadata import distribution
ModuleNotFoundError: No module named 'importlib.metadata'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/usr/bin/pip3", line 13, in <module>
from importlib_metadata import distribution
ModuleNotFoundError: No module named 'importlib_metadata'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/usr/local/lib/python3.7/site-packages/pkg_resources/__init__.py", line 584, in _build_master
ws.require(__requires__)
File "/usr/local/lib/python3.7/site-packages/pkg_resources/__init__.py", line 901, in require
needed = self.resolve(parse_requirements(requirements))
File "/usr/local/lib/python3.7/site-packages/pkg_resources/__init__.py", line 792, in resolve
raise VersionConflict(dist, req).with_context(dependent_req)
pkg_resources.VersionConflict: (pip 20.1.1 (/usr/local/lib/python3.7/site-packages), Requirement.parse('pip==20.3.4'))
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/usr/bin/pip3", line 15, in <module>
from pkg_resources import load_entry_point
File "/usr/local/lib/python3.7/site-packages/pkg_resources/__init__.py", line 3261, in <module>
@_call_aside
File "/usr/local/lib/python3.7/site-packages/pkg_resources/__init__.py", line 3245, in _call_aside
f(*args, **kwargs)
File "/usr/local/lib/python3.7/site-packages/pkg_resources/__init__.py", line 3274, in _initialize_master_working_set
working_set = WorkingSet._build_master()
File "/usr/local/lib/python3.7/site-packages/pkg_resources/__init__.py", line 586, in _build_master
return cls._build_from_requirements(__requires__)
File "/usr/local/lib/python3.7/site-packages/pkg_resources/__init__.py", line 599, in _build_from_requirements
dists = ws.resolve(reqs, Environment())
File "/usr/local/lib/python3.7/site-packages/pkg_resources/__init__.py", line 787, in resolve
raise DistributionNotFound(req, requirers)
pkg_resources.DistributionNotFound: The 'pip==20.3.4' distribution was not found and is required by the application
但是当我切换回 Python3.9 时，Pip 就可以工作了。我不知道如何解决这个问题。我在谷歌上查了一下，但找不到任何人遇到类似问题的问题。
