我如何更新Python虚拟环境以使用较新版本的Python？

Question

我最近在安装Python 3.8.0和Python 3.7.4的同时。

我有一些虚拟环境（使用基于v3.7.4的python -m venv <directory>创建。如何更新它们以使用v3.8.0？

我需要创建一个新的虚拟环境并重新安装依赖项，脚本等吗？

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注意：有一些现有的问与答（such as this）处理较旧的virtualenv软件包/工具。我对新的内置venv模块（这是新标准）特别感兴趣。

Answer 1

我猜您正在寻找的是--upgrade参数

python -m venv --help
usage: venv [-h] [--system-site-packages] [--symlinks | --copies] [--clear]
            [--upgrade] [--without-pip] [--prompt PROMPT]
            ENV_DIR [ENV_DIR ...]

Creates virtual Python environments in one or more target directories.

positional arguments:
  ENV_DIR               A directory to create the environment in.

optional arguments:
  -h, --help            show this help message and exit
  --system-site-packages
                        Give the virtual environment access to the system
                        site-packages dir.
  --symlinks            Try to use symlinks rather than copies, when symlinks
                        are not the default for the platform.
  --copies              Try to use copies rather than symlinks, even when
                        symlinks are the default for the platform.
  --clear               Delete the contents of the environment directory if it
                        already exists, before environment creation.
  --upgrade             Upgrade the environment directory to use this version
                        of Python, assuming Python has been upgraded in-place.
  --without-pip         Skips installing or upgrading pip in the virtual
                        environment (pip is bootstrapped by default)
  --prompt PROMPT       Provides an alternative prompt prefix for this
                        environment.