此环境由外部管理

Question

我正在尝试使用 pip 安装软件包，但是当运行命令

pip3 install requests

时，我收到以下错误：

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/>

我不确定为什么会发生这种情况，因为以前从未发生过，而且我在网上找到的任何内容似乎都无法帮助解决这个问题。 对于上下文，我使用的是 MAC，只写

pip

不起作用，只有

pip3

有效。

Answer 1

MacOS 似乎采用了包管理的指南，另见PEP 668。 基本上，您不应该混合系统安装的 Python 软件包和为 Python 开发安装的软件包。

如果您想在系统范围内安装软件包，请使用操作系统软件包管理器进行安装。如果适合您，请使用环境管理器（venv、conda 或任何变体/替代方案）。