Question

我最近将Python 3.8.2的Homebrew安装更新为3.8.3。这样做之后，我跑了

$ pip3 install -U pip

，以检查是否有任何pip更新。它将pip的安装从20.0.2更新到20.1.1，自从我运行该命令以来，pip每次尝试使用它都会引发错误。这是错误：

Traceback (most recent call last):
  File "/usr/local/lib/python3.8/site-packages/pkg_resources/__init__.py", line 584, in _build_master
    ws.require(__requires__)
  File "/usr/local/lib/python3.8/site-packages/pkg_resources/__init__.py", line 901, in require
    needed = self.resolve(parse_requirements(requirements))
  File "/usr/local/lib/python3.8/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/python3.8/site-packages), Requirement.parse('pip==20.0.2'))

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/local/opt/python@3.8/bin/pip3", line 6, in <module>
    from pkg_resources import load_entry_point
  File "/usr/local/lib/python3.8/site-packages/pkg_resources/__init__.py", line 3255, in <module>
    def _initialize_master_working_set():
  File "/usr/local/lib/python3.8/site-packages/pkg_resources/__init__.py", line 3238, in _call_aside
    f(*args, **kwargs)
  File "/usr/local/lib/python3.8/site-packages/pkg_resources/__init__.py", line 3267, in _initialize_master_working_set
    working_set = WorkingSet._build_master()
  File "/usr/local/lib/python3.8/site-packages/pkg_resources/__init__.py", line 586, in _build_master
    return cls._build_from_requirements(__requires__)
  File "/usr/local/lib/python3.8/site-packages/pkg_resources/__init__.py", line 599, in _build_from_requirements
    dists = ws.resolve(reqs, Environment())
  File "/usr/local/lib/python3.8/site-packages/pkg_resources/__init__.py", line 787, in resolve
    raise DistributionNotFound(req, requirers)
pkg_resources.DistributionNotFound: The 'pip==20.0.2' distribution was not found and is required by the application

在升级过程中似乎出现了问题，未能在代码中更改版本检查。我看到了this similar question，但是接受的答案对我没有用。 如何使pip再次可用？

Answer 1

根据Python文档，现在正确使用pip的方法是通过正确的Python可执行文件，例如

python3 -m pip install -U pip

Answer 2

我在Ubuntu上遇到了类似的问题，下面是解决问题的方法：

首先通过从OS软件包管理器中重新安装旧版本来还原旧版本（您可能需要先卸载）。
使用以下命令为您的用户升级到最新版本（而不是在系统位置安装）

pip3 install --user -U pip

希望这会有所帮助。

升级点后，它不再起作用

2 个答案: