Time To Upgrade Your Python

今天在虛擬環境中使用pip 安裝pylint的時候發現出現了TLS版本太低問題。

(py3env) ☁  py3env  pip install pylint 
Collecting pylint
  Could not fetch URL https://pypi.python.org/simple/pylint/: 
There was a problem confirming the ssl certificate: 
[SSL: TLSV1_ALERT_PROTOCOL_VERSION] tlsv1 alert protocol version (_ssl.c:720) - skipping
  Could not find a version that satisfies the requirement pylint (from versions: )
No matching distribution found for pylint

而後想起了去年有一篇文章說python.org和pypi將中止對TLS 1.0和1.1的支持，而後又找到了這篇文章

http://pyfound.blogspot.in/2017/01/time-to-upgrade-your-python-tls-v12.html 

文章中明確說明

Mac users should pay special attention. So far, the system Python shipped with MacOS does not yet support TLSv1.2 in any MacOS version; beginning next June these system Pythons will no longer be able to "pip install" packages.

Mac用戶應該特別注意，到目前爲止，MacOS附帶的系統Python在任何MacOS版本中都不支持TLSv1.2。因此是時候升級一下python3的版本了，並且能夠體驗一下python 3.6的異步解析式和生成器。

記錄一下升級到os X升級到python3.6的過程。

一、有必要先切換一下Homebrew的源，中科大鏡像源

替換brew.git:
cd "$(brew --repo)"
git remote set-url origin https://mirrors.ustc.edu.cn/brew.git

替換homebrew-core.git:
cd "$(brew --repo)/Library/Taps/homebrew/homebrew-core"
git remote set-url origin https://mirrors.ustc.edu.cn/homebrew-core.git

二、更新python3，直接安裝就會自動更新。

brew install python3

更新過程當中會遇到一個問題：

Error: The `brew link` step did not complete successfully

Error: Permission denied @ dir_s_mkdir - /usr/local/Frameworks

遇到這個權限問題的時候執行下面，

sudo mkdir -p /usr/local/Frameworks

sudo chown -R $(whoami) /usr/local/* 

而後在執行

brew link python3

可能會遇到以後這個問題：

Linking /usr/local/Cellar/python3/3.6.4_1... 

Error: Could not symlink bin/idle3

Target /usr/local/bin/idle3

already exists. You may want to remove it:

  rm '/usr/local/bin/idle3'

To force the link and overwrite all conflicting files:

  brew link --overwrite python3

To list all files that would be deleted:

  brew link --overwrite --dry-run python3

就更具提示把該刪除的刪除一下就行了 

rm /usr/local/bin/idle3
rm /usr/local/bin/pydoc3

在執行
brew link --overwrite python3

這樣就安裝成功了。

 

參考連接：

brew源更新: https://www.zhihu.com/question/31360766

低版本TLS中止支持公告 ： http://pyfound.blogspot.in/2017/01/time-to-upgrade-your-python-tls-v12.html

brew安裝python3 issue ： https://github.com/Homebrew/homebrew-core/issues/20985