Python v2->v3 アップデート

note.md

実行環境

• macOS Mojave ver 10.14.1
• Homebrew 1.8.4
• Xcode 10.1(10B61)

1. バージョン確認

$ python -V
Python 2.7.10

2. Homebrewを最新にする

$ brew update

3. インストール

$ brew install python3

4. Error, Error, Error...

Error: An unexpected error occurred during the `brew link` step
The formula built, but is not symlinked into /usr/local
Permission denied @ dir_s_mkdir - /usr/local/Frameworks
Error: Permission denied @ dir_s_mkdir - /usr/local/Frameworks

5. Fix Error

$ sudo mkdir /usr/local/Frameworks
$ sudo chown $(whoami):admin /usr/local/Frameworks

$ brew reinstall python

# ???
$ python -V
Python 2.7.10

6. 結局

$ python3 -V
Python 3.7.1

参考

• https://qiita.com/crankcube@github/items/15f06b32ec56736fc43a
• https://qiita.com/Jung0/items/d4012814e6fb1b694208
• https://www.python.jp/install/macos/index.html