pythonの古いバージョンのインストール
pythonの古いバージョン（例えば、3.8とか）をインストールしたいとき、 パッケージのlinkをしないと、それが使えなくなっている。
今回、python3.8をbrewでインストールして、パッケージのlinkをやり直して、 コマンド名を「python」に書き換えるまでをやってみる。
#pythonのパス確認 => /usr/bin内のpythonが参照されている。 $ which python /usr/bin/python #python@3.8のインストール $ brew install python@3.8 #... #... #==> Summary #🍺 /usr/local/Cellar/tcl-tk/8.6.11_1: 3,041 files, 51.6MB #==> Installing python@3.8 #==> Pouring python@3.8-3.8.7_2.catalina.bottle.tar.gz #==> /usr/local/Cellar/python@3.8/3.8.7_2/bin/python3 -s setup.py --no-user-cfg i #==> /usr/local/Cellar/python@3.8/3.8.7_2/bin/python3 -s setup.py --no-user-cfg i #==> /usr/local/Cellar/python@3.8/3.8.7_2/bin/python3 -s setup.py --no-user-cfg i #==> Caveats #Python has been installed as # /usr/local/opt/python@3.8/bin/python3 # #Unversioned symlinks `python`, `python-config`, `pip` etc. pointing to #`python3`, `python3-config`, `pip3` etc., respectively, have been installed into # /usr/local/opt/python@3.8/libexec/bin # #You can install Python packages with # /usr/local/opt/python@3.8/bin/pip3 install <package> #They will install into the site-package directory # /usr/local/lib/python3.8/site-packages #...
ただ、これだけでは、pythonがアップデートされていない。
#pythonのパス確認 $ which python /usr/bin/python #python3のパス確認 $ which python3 /usr/bin/python3
python@3.8へとlinkを書き換える
そこで、python@3.8へとlinkを書き換える。
そうすると、/usr/local/bin内の、python3が参照される。
#リンクの上書き $ brew link --overwrite python@3.8 #パス確認 $ which python3 /usr/local/bin/python3
pythonとpip関連コマンドのエイリアス名を書き換える
次に、/usr/local/bin内で、pythonとpip関連コマンドのエイリアス名を書き換える。
#pythonとpip関連コマンドの表示 $ ls /usr/local/bin | grep -e "py" -e "pip" #pip3 #pip3.8 #pydoc3 #pydoc3.8 #python3 #python3-config #python3.8 #python3.8-config #エイリアス名の書き換え mv /usr/local/bin/pip3 /usr/local/bin/pip mv /usr/local/bin/pydoc3 /usr/local/bin/pydoc mv /usr/local/bin/python3 /usr/local/bin/python mv /usr/local/bin/python3-config /usr/local/bin/python-config
上記を行うと、python、pipコマンドがそれぞれ、python3.8と紐づけられる。
$ which python /usr/local/bin/python $ python -V Python 3.8.7 $ which pip /usr/local/bin/pip $ pip -V pip 20.3.3 from /usr/local/lib/python3.8/site-packages/pip (python 3.8)
以上、おしまい。
補足
2021年3月4日現在、brew infoで調べたところ、python@3.7以上しか、リポジトリにはないらしい。
$ brew info python@3.6 Error: No available formula or cask with the name "python@3.6". ==> Searching for a previously deleted formula (in the last month)... Error: No previously deleted formula found. $ brew info python@3.7 python@3.7: stable 3.7.10 (bottled) [keg-only] Interpreted, interactive, object-oriented programming language https://www.python.org/ Not installed From: https://github.com/Homebrew/homebrew-core/blob/HEAD/Formula/python@3.7.rb License: Python-2.0 ==> Dependencies Build: pkg-config ✔ Required: gdbm ✔, mpdecimal ✘, openssl@1.1 ✔, readline ✔, sqlite ✔, xz ✔ ==> Requirements Required: x86_64 architecture ✔ ==> Caveats Python has been installed as /usr/local/opt/python@3.7/bin/python3 Unversioned symlinks `python`, `python-config`, `pip` etc. pointing to `python3`, `python3-config`, `pip3` etc., respectively, have been installed into /usr/local/opt/python@3.7/libexec/bin You can install Python packages with /usr/local/opt/python@3.7/bin/pip3 install <package> They will install into the site-package directory /usr/local/lib/python3.7/site-packages See: https://docs.brew.sh/Homebrew-and-Python python@3.7 is keg-only, which means it was not symlinked into /usr/local, because this is an alternate version of another formula. ==> Analytics install: 33,684 (30 days), 73,067 (90 days), 197,222 (365 days) install-on-request: 27,647 (30 days), 63,841 (90 days), 141,223 (365 days) build-error: 0 (30 days) $ brew info python@3.8 python@3.8: stable 3.8.8 (bottled) [keg-only] Interpreted, interactive, object-oriented programming language https://www.python.org/ Not installed From: https://github.com/Homebrew/homebrew-core/blob/HEAD/Formula/python@3.8.rb License: Python-2.0 ==> Dependencies Build: pkg-config ✔ Required: gdbm ✔, mpdecimal ✘, openssl@1.1 ✔, readline ✔, sqlite ✔, tcl-tk ✔, xz ✔ ==> Caveats Python has been installed as /usr/local/opt/python@3.8/bin/python3 Unversioned symlinks `python`, `python-config`, `pip` etc. pointing to `python3`, `python3-config`, `pip3` etc., respectively, have been installed into /usr/local/opt/python@3.8/libexec/bin You can install Python packages with /usr/local/opt/python@3.8/bin/pip3 install <package> They will install into the site-package directory /usr/local/lib/python3.8/site-packages See: https://docs.brew.sh/Homebrew-and-Python python@3.8 is keg-only, which means it was not symlinked into /usr/local, because this is an alternate version of another formula. ==> Analytics install: 348,989 (30 days), 851,949 (90 days), 4,803,149 (365 days) install-on-request: 187,812 (30 days), 509,836 (90 days), 1,521,919 (365 days) build-error: 0 (30 days)
