当你使用MacOS 通过brew 安装了python，并且是python3.12。
当你想使用pip3 安装第三方库时，你遇到了以下报错：

error: externally-managed-environment

× This environment is externally managed
╰─> To install Python packages system-wide, try brew install
xyz, where xyz is the package you are trying to
install.

If you wish to install a Python library that isn't in Homebrew,
use a virtual environment:

python3 -m venv path/to/venv
source path/to/venv/bin/activate
python3 -m pip install xyz

If you wish to install a Python application that isn't in Homebrew,
it may be easiest to use 'pipx install xyz', which will manage a
virtual environment for you. You can install pipx with

brew install pipx

You may restore the old behavior of pip by passing
the '--break-system-packages' flag to pip, or by adding
'break-system-packages = true' to your pip.conf file. The latter
will permanently disable this error.

If you disable this error, we STRONGLY recommend that you additionally
pass the '--user' flag to pip, or set 'user = true' in your pip.conf
file. Failure to do this can result in a broken Homebrew installation.

Read more about this behavior here: <https://peps.python.org/pep-0668/>

note: If you believe this is a mistake, please contact your Python installation or OS distribution provider. You can override this, at the risk of breaking your Python installation or OS, by passing --break-system-packages.
hint: See PEP 668 for the detailed specification.

解决方法

你可以像这里描述的那样使用Python的venv。
但是，如果你确实需要继续使用pip3 install xyz这种方法来安装第三方库，那么有两个解决方案：

• use pip’s argument --break-system-packages,
• 在 ~/.config/pip/pip.conf 添加上这一行:

[global]
break-system-packages = true