macOS系统下新版本发布时，如何更新已安装的Python 3.6.5？

Hey there! Since you're running macOS with Python 3.6.5 already, let's walk through the most reliable ways to update to a newer Python version—no messy system overrides, promise:

If you want a no-fuss, straightforward update, go with the official Python installer:

• Head to the official Python website and download the latest stable release's .pkg installer.
• Open the downloaded file and follow the installation wizard. By default, it’ll install the new version in /Library/Frameworks/Python.framework/Versions/.
• After installation, check your current Python version with python3 --version. If it still shows 3.6.5, you’ll need to add the new version to your system path:
  1. Open your shell config file (either ~/.zshrc for Zsh or ~/.bash_profile for Bash) in a text editor.
  2. Add this line, replacing [NEW_VERSION] with the actual version number (like 3.12):

     export PATH="/Library/Frameworks/Python.framework/Versions/[NEW_VERSION]/bin:$PATH"
     

  3. Save the file, then run source ~/.zshrc (or source ~/.bash_profile) to apply the changes. Now python3 --version should show the new version.

If you already use Homebrew for package management, this is super smooth:

• First, make sure Homebrew is up to date:

  brew update
  

• Install the latest Python release:

  brew install python
  

• Homebrew will automatically set the new Python version as your default. Verify with python3 --version.
• If you have old Python versions lingering, clean them up with:

  brew cleanup python
  

If you need to switch between multiple Python versions (like keeping 3.6.5 for old projects and using a new version for others), pyenv is your best bet—it keeps versions isolated so you don’t mess up your system or existing projects:

• Install pyenv via Homebrew:

  brew install pyenv
  

• Configure your shell to use pyenv. Open your ~/.zshrc or ~/.bash_profile and add these lines:

  export PYENV_ROOT="$HOME/.pyenv"
  command -v pyenv >/dev/null || export PATH="$PYENV_ROOT/bin:$PATH"
  eval "$(pyenv init -)"
  

• Save the file and run source ~/.zshrc (or your respective config file) to activate the changes.
• List all available Python versions you can install:

  pyenv install --list
  

• Install the version you want (replace 3.12.0 with your target version):

  pyenv install 3.12.0
  

• Set the new version as your global default:

  pyenv global 3.12.0
  

• Verify with python --version (pyenv makes python point to your selected version now).

Quick Notes: #

• Never mess with the system Python: macOS relies on its built-in Python version for system tools. All methods above install separate, independent Python versions so you won’t break your OS.
• When using pip, the new Python version will have its own pip (usually pip3). Run pip3 install [package-name] to install packages for the new version.

内容的提问来源于stack exchange，提问作者berkb