前言

目前 Python 同时更新与维护 Python2 和 Python3，选择 Python2 还是选择 Python3，取决于当前要使用的库、框架支持哪个版本，所以经常会遇到切换版本的情况。那么 macOS 下应该怎样有效的更改呢？很多小伙伴一定会想到修改环境变量，指定 Python 的默认路径，这样当然可以，然而不够优雅。那么怎样的方法才算优雅呢？当然是一条命令了。这里通过 brew 安装 pyenv，再用 pyenv 安装管理 Python。

macOS 使用 pyenv 安装和管理多个 Python 版本

更新历史

2018 年 12 月 16 日 - 初稿

阅读原文 - https://wsgzao.github.io/post/macos-pyenv/

扩展阅读

pyenv - https://github.com/pyenv/pyenv

pyenv 简介

pyenv lets you easily switch between multiple versions of Python. It's simple, unobtrusive, and follows the UNIX tradition of single-purpose tools that do one thing well.

This project was forked from rbenv and ruby-build, and modified for Python.

pyenv does...

• Let you change the global Python version on a per-user basis.
• Provide support for per-project Python versions.
• Allow you to override the Python version with an environment variable.
• Search commands from multiple versions of Python at a time. This may be helpful to test across Python versions with tox.

In contrast with pythonbrew and pythonz, pyenv does not...

• Depend on Python itself. pyenv was made from pure shell scripts. There is no bootstrap problem of Python.
• Need to be loaded into your shell. Instead, pyenv's shim approach works by adding a directory to your $PATH.
• Manage virtualenv. Of course, you can create virtualenv yourself, or pyenv-virtualenv to automate the process.

安装 pyenv

Homebrew 是 macOS 下非常高效的命令行软件包管理器，mac 必安装工具之一

# 安装 homebrew
/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
brew -v
Homebrew 1.8.5
Homebrew/homebrew-core (git revision 497ca; last commit 2018-12-16)
Homebrew/homebrew-cask (git revision 8be7c; last commit 2018-12-17)
安装 pyenv
brew update
brew install pyenv
pyenv -v
pyenv 1.2.8
安装管理多个 Python
pyenv install --list
Available versions:
2.1.3
2.2.3
2.3.7
2.4
2.4.1
2.4.2
2.4.3
2.4.4
2.4.5
2.4.6
2.5
2.5.1
2.5.2
2.5.3
2.5.4
2.5.5
2.5.6
2.6.6
2.6.7
2.6.8
2.6.9
2.7-dev
2.7
2.7.1
2.7.2
2.7.3
2.7.4
2.7.5
2.7.6
2.7.7
2.7.8
2.7.9
2.7.10
2.7.11
2.7.12
2.7.13
2.7.14
2.7.15
3.0.1
3.1
3.1.1
3.1.2
3.1.3
3.1.4
3.1.5
3.2
3.2.1
3.2.2
3.2.3
3.2.4
3.2.5
3.2.6
3.3.0
3.3.1
3.3.2
3.3.3
3.3.4
3.3.5
3.3.6
3.3.7
3.4.0
3.4-dev
3.4.1
3.4.2
3.4.3
3.4.4
3.4.5
3.4.6
3.4.7
3.4.8
3.4.9
3.5.0
3.5-dev
3.5.1
3.5.2
3.5.3
3.5.4
3.5.5
3.5.6
3.6.0
3.6-dev
3.6.1
3.6.2
3.6.3
3.6.4
3.6.5
3.6.6
3.6.7
3.7.0
3.7-dev
3.7.1
3.8-dev
activepython-2.7.14
activepython-3.5.4
activepython-3.6.0
anaconda-1.4.0
anaconda-1.5.0
anaconda-1.5.1
anaconda-1.6.0
anaconda-1.6.1
anaconda-1.7.0
anaconda-1.8.0
anaconda-1.9.0
anaconda-1.9.1
anaconda-1.9.2
anaconda-2.0.0
anaconda-2.0.1
anaconda-2.1.0
anaconda-2.2.0
anaconda-2.3.0
anaconda-2.4.0
anaconda-4.0.0
anaconda2-2.4.0
anaconda2-2.4.1
anaconda2-2.5.0
anaconda2-4.0.0
anaconda2-4.1.0
anaconda2-4.1.1
anaconda2-4.2.0
anaconda2-4.3.0
anaconda2-4.3.1
anaconda2-4.4.0
anaconda2-5.0.0
anaconda2-5.0.1
anaconda2-5.1.0
anaconda2-5.2.0
anaconda2-5.3.0
anaconda3-2.0.0
anaconda3-2.0.1
anaconda3-2.1.0
anaconda3-2.2.0
anaconda3-2.3.0
anaconda3-2.4.0
anaconda3-2.4.1
anaconda3-2.5.0
anaconda3-4.0.0
anaconda3-4.1.0
anaconda3-4.1.1
anaconda3-4.2.0
anaconda3-4.3.0
anaconda3-4.3.1
anaconda3-4.4.0
anaconda3-5.0.0
anaconda3-5.0.1
anaconda3-5.1.0
anaconda3-5.2.0
anaconda3-5.3.0
ironpython-dev
ironpython-2.7.4
ironpython-2.7.5
ironpython-2.7.6.3
ironpython-2.7.7
jython-dev
jython-2.5.0
jython-2.5-dev
jython-2.5.1
jython-2.5.2
jython-2.5.3
jython-2.5.4-rc1
jython-2.7.0
jython-2.7.1
micropython-dev
micropython-1.9.3
micropython-1.9.4
miniconda-latest
miniconda-2.2.2
miniconda-3.0.0
miniconda-3.0.4
miniconda-3.0.5
miniconda-3.3.0
miniconda-3.4.2
miniconda-3.7.0
miniconda-3.8.3
miniconda-3.9.1
miniconda-3.10.1
miniconda-3.16.0
miniconda-3.18.3
miniconda2-latest
miniconda2-3.18.3
miniconda2-3.19.0
miniconda2-4.0.5
miniconda2-4.1.11
miniconda2-4.3.14
miniconda2-4.3.21
miniconda2-4.3.27
miniconda2-4.3.30
miniconda3-latest
miniconda3-2.2.2
miniconda3-3.0.0
miniconda3-3.0.4
miniconda3-3.0.5
miniconda3-3.3.0
miniconda3-3.4.2
miniconda3-3.7.0
miniconda3-3.8.3
miniconda3-3.9.1
miniconda3-3.10.1
miniconda3-3.16.0
miniconda3-3.18.3
miniconda3-3.19.0
miniconda3-4.0.5
miniconda3-4.1.11
miniconda3-4.2.12
miniconda3-4.3.11
miniconda3-4.3.14
miniconda3-4.3.21
miniconda3-4.3.27
miniconda3-4.3.30
pypy-c-jit-latest
pypy-c-nojit-latest
pypy-dev
pypy-stm-2.3
pypy-stm-2.5.1
pypy-1.5-src
pypy-1.5
pypy-1.6
pypy-1.7
pypy-1.8
pypy-1.9
pypy-2.0-src
pypy-2.0
pypy-2.0.1-src
pypy-2.0.1
pypy-2.0.2-src
pypy-2.0.2
pypy-2.1-src
pypy-2.1
pypy-2.2-src
pypy-2.2
pypy-2.2.1-src
pypy-2.2.1
pypy-2.3-src
pypy-2.3
pypy-2.3.1-src
pypy-2.3.1
pypy-2.4.0-src
pypy-2.4.0
pypy-2.5.0-src
pypy-2.5.0
pypy-2.5.1-src
pypy-2.5.1
pypy-2.6.0-src
pypy-2.6.0
pypy-2.6.1-src
pypy-2.6.1
pypy-4.0.0-src
pypy-4.0.0
pypy-4.0.1-src
pypy-4.0.1
pypy-5.0.0-src
pypy-5.0.0
pypy-5.0.1-src
pypy-5.0.1
pypy-5.1-src
pypy-5.1
pypy-5.1.1-src
pypy-5.1.1
pypy-5.3-src
pypy-5.3
pypy-5.3.1-src
pypy-5.3.1
pypy-5.4-src
pypy-5.4
pypy-5.4.1-src
pypy-5.4.1
pypy-5.6.0-src
pypy-5.6.0
pypy-5.7.0-src
pypy-5.7.0
pypy-5.7.1-src
pypy-5.7.1
pypy2-5.3-src
pypy2-5.3
pypy2-5.3.1-src
pypy2-5.3.1
pypy2-5.4-src
pypy2-5.4
pypy2-5.4.1-src
pypy2-5.4.1
pypy2-5.6.0-src
pypy2-5.6.0
pypy2-5.7.0-src
pypy2-5.7.0
pypy2-5.7.1-src
pypy2-5.7.1
pypy2.7-5.8.0-src
pypy2.7-5.8.0
pypy2.7-5.9.0-src
pypy2.7-5.9.0
pypy2.7-5.10.0-src
pypy2.7-5.10.0
pypy2.7-6.0.0-src
pypy2.7-6.0.0
pypy3-dev
pypy3-2.3.1-src
pypy3-2.3.1
pypy3-2.4.0-src
pypy3-2.4.0
pypy3.3-5.2-alpha1-src
pypy3.3-5.2-alpha1
pypy3.3-5.5-alpha-src
pypy3.3-5.5-alpha
pypy3.5-c-jit-latest
pypy3.5-5.7-beta-src
pypy3.5-5.7-beta
pypy3.5-5.7.1-beta-src
pypy3.5-5.7.1-beta
pypy3.5-5.8.0-src
pypy3.5-5.8.0
pypy3.5-5.9.0-src
pypy3.5-5.9.0
pypy3.5-5.10.0-src
pypy3.5-5.10.0
pypy3.5-5.10.1-src
pypy3.5-5.10.1
pypy3.5-6.0.0-src
pypy3.5-6.0.0
pyston-0.5.1
pyston-0.6.0
pyston-0.6.1
stackless-dev
stackless-2.7-dev
stackless-2.7.2
stackless-2.7.3
stackless-2.7.4
stackless-2.7.5
stackless-2.7.6
stackless-2.7.7
stackless-2.7.8
stackless-2.7.9
stackless-2.7.10
stackless-2.7.11
stackless-2.7.12
stackless-2.7.14
stackless-3.2.2
stackless-3.2.5
stackless-3.3.5
stackless-3.3.7
stackless-3.4-dev
stackless-3.4.1
stackless-3.4.2
stackless-3.4.7
stackless-3.5.4
选择 Python 所需版本
pyenv install 2.7.15
pyenv install 3.6.7
初始化
pyenv init
Load pyenv automatically by appending
the following to ~/.zshrc:
eval “$(pyenv init -)”
重启 zsh
exec “$SHELL”
切换版本
pyenv global 2.7.15
pyenv shell 3.6.7
查看版本
pyenv versions
system
2.7.15

3.6.7 (set by PYENV_VERSION environment variable)

pyenv 常用的命令说明
使用方式: pyenv <命令> [<参数>]
命令:
commands    查看所有命令
local       设置或显示本地的 Python 版本
global      设置或显示全局 Python 版本
shell       设置或显示 shell 指定的 Python 版本
install     安装指定 Python 版本
uninstall   卸载指定 Python 版本)
version     显示当前的 Python 版本及其本地路径
versions    查看所有已经安装的版本
which       显示安装路径
pyenv
pyenv 1.2.8
Usage: pyenv <command> [<args>]
Some useful pyenv commands are:
commands    List all available pyenv commands
local       Set or show the local application-specific Python version
global      Set or show the global Python version
shell       Set or show the shell-specific Python version
install     Install a Python version using python-build
uninstall   Uninstall a specific Python version
rehash      Rehash pyenv shims (run this after installing executables)
version     Show the current Python version and its origin
versions    List all Python versions available to pyenv
which       Display the full path to an executable
whence      List all Python versions that contain the given executable
See `pyenv help <command>’ for information on a specific command.
For full documentation, see: https://github.com/pyenv/pyenv#readme

Mac 中安装 PySpider

在 PySpider 支持 Python3.7 之前只能暂时降级 Python

# 使用 pyenv 切换 python 版本
brew install pyenv
pyenv install 3.6.7
pyenv shell 3.6.7
创建 PySpider 虚拟环境
mkdir pyspider
cd pyspider
python -m venv venv
source venv/bin/active
pip install pyspider
安装期间出现 SSL 或 pycurl 错误
main.ConfigurationError: Curl is configured to use SSL, but we have not been able to determine which SSL backend it is using. Please see PycURL documentation for how to specify the SSL backend manually.
解决方法
pip uninstall pycurl
export PYCURL_SSL_LIBRARY=openssl
export LDFLAGS=-L/usr/local/opt/openssl/lib;export CPPFLAGS=-I/usr/local/opt/openssl/include;pip install pycurl --compile --no-cache-dir
重新安装并运行 pyspider
pip install pyspider
pyspider
[W 181217 15:23:35 run:413] phantomjs not found, continue running without it.
[I 181217 15:23:37 result_worker:49] result_worker starting…
[I 181217 15:23:37 processor:211] processor starting…
[I 181217 15:23:37 tornado_fetcher:638] fetcher starting…
[I 181217 15:23:37 scheduler:647] scheduler starting…
[I 181217 15:23:37 scheduler:782] scheduler.xmlrpc listening on 127.0.0.1:23333
[I 181217 15:23:37 scheduler:586] in 5m: new:0,success:0,retry:0,failed:0
[I 181217 15:23:37 app:76] webui running on 0.0.0.0:5000