安装

快捷安装

# mac
$ brew install pyenv

源码安装

# Check out pyenv
$ git clone https://github.com/pyenv/pyenv.git ~/.pyenv
 
# Define environment variable PYENV_ROOT
$ echo 'export PYENV_ROOT="$HOME/.pyenv"' >> ~/.bash_profile
$ echo 'export PATH="$PYENV_ROOT/bin:$PATH"' >> ~/.bash_profile

# Add pyenv init to your shell
$ echo -e 'if command -v pyenv 1>/dev/null 2>&1; then\n  eval "$(pyenv init -)"\nfi' >> ~/.bash_profile

# Restart your shell
exec "$SHELL"

# Just run!
$ pyenv -v
pyenv 1.2.17-1-g89786b90

注意：

• Zsh：修改~/.zshrc文件而不是~/.bash_profile。
• Ubuntu、Fedora：修改~/.bashrc文件而不是~/.bash_profile。

使用

安装需要的python版本：

# install python
$ pyenv install 2.7.8

$ pyenv install 3.8.2

$ pyenv versions
  system
  2.7.8
* 3.8.2 (set by /Users/youshu/.pyenv/version)

一般有一个2.7，一个3.8就够了。

如果不确定哪些版本支持，可以查看pyenv支持安装的Python版本有哪些：

$ pyenv install --list

使用指定版本Python：

$ pyenv local 2.7.8
$ python -V
Python 2.7.8

使用local指令只是在当前shell切换到指定版本，如果需要全局生效，则需要使用global指令：

$ pyenv global 3.8.2
$ python -V
Python 3.8.2

使用最新版本

如果你需要的版本不在pyenv支持的列表里，可以手动新增。~/.pyenv/plugins/python-build/share/python-build/目录存放的就是各个版本的下载地址，文件名就是Python的版本名。

$ ls ~/.pyenv/plugins/python-build/share/python-build/
2.1.3                  3.3.6                  anaconda-1.6.1         ironpython-2.7.7       miniconda3-3.9.1       pypy-5.1               pypy3.3-5.2-alpha1 
...

下面是3.8.2的内容:

$ cat ~/.pyenv/plugins/python-build/share/python-build/3.8.2
#require_gcc
prefer_openssl11
export PYTHON_BUILD_CONFIGURE_WITH_OPENSSL=1
install_package "openssl-1.1.0j" "https://www.openssl.org/source/openssl-1.1.0j.tar.gz#31bec6c203ce1a8e93d5994f4ed304c63ccf07676118b6634edded12ad1b3246" mac_openssl --if has_broken_mac_openssl
install_package "readline-8.0" "https://ftpmirror.gnu.org/readline/readline-8.0.tar.gz#e339f51971478d369f8a053a330a190781acb9864cf4c541060f12078948e461" mac_readline --if has_broken_mac_readline
if has_tar_xz_support; then
  install_package "Python-3.8.2" "https://www.python.org/ftp/python/3.8.2/Python-3.8.2.tar.xz#2646e7dc233362f59714c6193017bb2d6f7b38d6ab4a0cb5fbac5c36c4d845df" ldflags_dirs standard verify_py38 copy_python_gdb ensurepip
else
  install_package "Python-3.8.2" "https://www.python.org/ftp/python/3.8.2/Python-3.8.2.tgz#e634a7a74776c2b89516b2e013dda1728c89c8149b9863b8cea21946daf9d561" ldflags_dirs standard verify_py38 copy_python_gdb ensurepip
fi

帮助

$ pyenv -h
Usage: pyenv <command> [<args>]

Some useful pyenv commands are:
   --version   Display the version of pyenv
   commands    List all available pyenv commands
   exec        Run an executable with the selected Python version
   global      Set or show the global Python version
   help        Display help for a command
   hooks       List hook scripts for a given pyenv command
   init        Configure the shell environment for pyenv
   install     Install a Python version using python-build
   local       Set or show the local application-specific Python version
   prefix      Display prefix for a Python version
   rehash      Rehash pyenv shims (run this after installing executables)
   root        Display the root directory where versions and shims are kept
   shell       Set or show the shell-specific Python version
   shims       List existing pyenv shims
   uninstall   Uninstall a specific Python version
   version     Show the current Python version and its origin
   version-file   Detect the file that sets the current pyenv version
   version-name   Show the current Python version
   version-origin   Explain how the current Python version is set
   versions    List all Python versions available to pyenv
   whence      List all Python versions that contain the given executable
   which       Display the full path to an executable

See `pyenv help <command>' for information on a specific command.
For full documentation, see: https://github.com/pyenv/pyenv#readme

参考

1、pyenv/pyenv: Simple Python version management
https://github.com/pyenv/pyenv