投稿者: notemite_admin

mysqlclient をインストールしたので、実際にクエリを実行できるか簡単に確認します。

今回は WordPress で自動作成されたテーブルで、現在公開されている記事のタイトルを select しました。

% python3
Python 3.9.0 (default, Jan  3 2021, 10:29:59) 
[GCC 4.2.1 20070831 patched [FreeBSD]] on freebsd9
Type "help", "copyright", "credits" or "license" for more information.

>>> import MySQLdb
>>> conn = MySQLdb.connect(host='mysqlXXX.db.sakura.ne.jp', db='abcabc_notemite',user='abcabc',passwd='xxxxxxxxxxxx',charset='utf8mb4')
>>> c = conn.cursor()
>>> c.execute('select post_title from nm_posts where post_status = "publish"')
20
>>> c.fetchall()
(('サンプルページ',), ('【Wordpress】ショートコードを別ファイル管理でリスク低減',), ('【WordPress】ショートコードの表示・非表示を一発で切り替えたい',), ('【ターミナル】Mac のログインシェルを zsh に変える',), ('【Python】Macbook に Python3 をインストール',), ('【Python】「pip install requests」でエラー「pip3 install requests」で成功',), ('【Python】Mac に Beautifulsoup4 をインストール',), ('Homebrew を Macbook Pro へインストール',), ('Homebrew を使って Macbook に Wget をインストール',), ('【Wordpress】確かに「--」と書いたのに「–」と表示される件',), ('【８ステップでがんばる】さくらレンタルサーバーでWordPressサイト立ち上げ',), ('【ターミナル】さくらのレンタルサーバーにSSHでログインする方法',), ('さくらレンタルサーバに Python3 をインストールする方法',), ('【Python】さくらレンタルサーバーに requests モジュールをインストール',), ('【Python】Mac に MySQL モジュールをインストールする方法',), ('【2020年10月〜12月】YouTube 急上昇入りランキング',), ('さくらレンタルサーバーに libffi をインストールする',), ('【2020年1月〜】YouTube 急上昇入りランキング',), ('さくらレンタルサーバーで Python3 を再インストール',), ('【Python3】mysqlclient のために _ctypes と格闘した記録',))
>>> 

execute() の実行結果（上記「20」の部分）はクエリの結果として返されたレコード数を表示しています。fetchall() を実行しないとクエリの実行結果は見れないんですね。

環境

OS: macOS Catalina バージョン 10.15.4
Python: Python 3.8.3

やりたいこと

Python で MySQLdb モジュールを使える様にしたい。

mysql をインストール

まず Homebrew で MySQL をインストールする必要があるので「brew install mysql」を実行します。

これをしていないとこの後 pip で「mysqlclient」のインストールができません。

(scraping) % brew install mysql
Updating Homebrew...
==> Auto-updated Homebrew!
Updated 1 tap (homebrew/core).
==> New Formulae
acl2                       heksa                      nfpm
act                        httpx                      ngs
airshare                   hy                         notmuch-mutt
alsa-lib                   i686-elf-binutils          numcpp
amp                        i686-elf-gcc               oci-cli
apidoc                     idris2                     omake
arb                        infracost                  openfst
argo                       inja                       oq
argocd                     inko                       ormolu
arrayfire                  ioctl                      ory-hydra
asimov                     jerryscript                osi
asroute                    jimtcl                     osm
athenacli                  jinx                       packetbeat
austin                     jobber                     packr
awsweeper                  jsonnet-bundler            pandoc-include-code
blogc                      k9s                        pandocomatic
bombadillo                 kde-karchive               parallel-hashmap
bond                       kde-kdoctools              periscope
borgbackup                 kde-ki18n                  pipgrip
box2d                      kde-threadweaver           po4a
buildozer                  kona                       podman
c7n                        kondo                      postgresql@12
cadence                    ksync                      prometheus-cpp
carton                     kubie                      promtail
cassowary                  ladspa-sdk                 protoc-gen-go-grpc
castget                    latexindent                protoc-gen-gogo
cbc                        ldpl                       protoc-gen-gogofaster
cdktf                      leaf                       pwncat
cgl                        libaio                     python@3.7
chalk-cli                  libcouchbase@2             python@3.9
charge                     libdmx                     reg
chart-testing              libdrm                     rgf
choose-rust                libfontenc                 rqlite
chrony                     libfs                      rust-analyzer
clair                      libgccjit                  rustscan
clang-format@8             libgnt                     s2n
cli11                      libhandy                   saltwater
cloud-nuke                 libice                     scw@1
cloudformation-cli         libirecovery               sdns
cloudformation-guard       libmnl                     server-go
coconut                    libnetfilter-queue         shallow-backup
colfer                     libnetworkit               sheldon
commitizen                 libnfnetlink               shtools
copilot                    liboqs                     silicon
coredns                    libpciaccess               simdjson
cortex                     libpthread-stubs           skylighting
cpio                       libseccomp                 sleef
cpm                        libsm                      smlpkg
cpr                        libx11                     snap
croaring                   libxau                     so
croc                       libxaw                     solidity
cubejs-cli                 libxaw3d                   sonic
cvs-fast-export            libxcb                     sponge
datasette                  libxcomposite              sqlite-utils
dbdeployer                 libxcursor                 standardese
diskonaut                  libxdamage                 staticcheck
dnsprobe                   libxdmcp                   structurizr-cli
doctest                    libxext                    subfinder
dosbox-staging             libxfixes                  termcolor
dotnet                     libxfont                   terraform-ls
duckscript                 libxft                     terraform@0.12
eksctl                     libxi                      terrascan
eleventy                   libxinerama                tfsec
empty                      libxkbfile                 thanos
envoy                      libxmu                     toot
fava                       libxpm                     torchvision
fblog                      libxrandr                  tre-command
fennel                     libxrender                 trunk
fetch                      libxres                    ugrep
flank                      libxscrnsaver              uptoc
fleet-cli                  libxshmfence               usb.ids
flit                       libxt                      util-macros
folderify                  libxtst                    vapor
font-util                  libxv                      vcpkg
foreman                    libxvmc                    vgrep
fpart                      libxxf86dga                vivid
fpdns                      libxxf86vm                 vlang
functionalplus             litecli                    volk
gateway-go                 localstack                 vsearch
gcc@9                      logcli                     vtk@8.2
git-hooks-go               loki                       webify
git-hound                  lunchy                     wgcf
gitql                      lunchy-go                  wownero
gitui                      macos-trash                wren
gluon                      mandown                    wren-cli
go@1.14                    mariadb@10.4               x86_64-elf-gdb
gofish                     marked                     xcb-proto
golangci-lint              mask                       xdpyinfo
gostatic                   matplotplusplus            xorgproto
gradle-profiler            mhonarc                    xtrans
gravity                    microplane                 yj
grpcui                     naabu                      z.lua
gulp-cli                   nanorc                     zoxide
halide                     nest                       zsh-you-should-use
hashlink                   networkit
hasura-cli                 never
==> Updated Formulae
Updated 4645 formulae.
==> Renamed Formulae
elasticsearch@6.8 -> elasticsearch@6
gst-validate -> gst-devtools
interactive-rebase-tool -> git-interactive-rebase-tool
jfrog-cli-go -> jfrog-cli
kibana@6.8 -> kibana@6
mkl-dnn -> onednn
==> Deleted Formulae
baidupcs-go         elasticsearch@5.6   marathon-swift      unravel
biogeme             highlighting-kate   python              urbit
cargo-completion    i386-elf-grub       residualvm          wpscan
cryptopp            kibana@5.6          sflowtool           xu4
elasticsearch@2.4   lumo                tomee-jax-rs

==> Downloading https://homebrew.bintray.com/bottles/openssl%401.1-1.1.1h.catali
==> Downloading from https://d29vzk4ow07wi7.cloudfront.net/4e5357c0cfd55cfa4ef0b
######################################################################## 100.0%
==> Downloading https://homebrew.bintray.com/bottles/protobuf-3.13.0.catalina.bo
==> Downloading from https://d29vzk4ow07wi7.cloudfront.net/af2990ba0a6e5588ef2af
######################################################################## 100.0%
==> Downloading https://homebrew.bintray.com/bottles/mysql-8.0.21_1.catalina.bot
==> Downloading from https://d29vzk4ow07wi7.cloudfront.net/81e92d0df39edaff415e7
######################################################################## 100.0%
==> Installing dependencies for mysql: openssl@1.1 and protobuf
==> Installing mysql dependency: openssl@1.1
==> Pouring openssl@1.1-1.1.1h.catalina.bottle.tar.gz
==> Caveats
A CA file has been bootstrapped using certificates from the system
keychain. To add additional certificates, place .pem files in
  /usr/local/etc/openssl@1.1/certs

and run
  /usr/local/opt/openssl@1.1/bin/c_rehash

openssl@1.1 is keg-only, which means it was not symlinked into /usr/local,
because macOS provides LibreSSL.

If you need to have openssl@1.1 first in your PATH run:
  echo 'export PATH="/usr/local/opt/openssl@1.1/bin:$PATH"' >> ~/.zshrc

For compilers to find openssl@1.1 you may need to set:
  export LDFLAGS="-L/usr/local/opt/openssl@1.1/lib"
  export CPPFLAGS="-I/usr/local/opt/openssl@1.1/include"

==> Summary
🍺  /usr/local/Cellar/openssl@1.1/1.1.1h: 8,067 files, 18.5MB
==> Installing mysql dependency: protobuf
==> Pouring protobuf-3.13.0.catalina.bottle.tar.gz
==> Caveats
Emacs Lisp files have been installed to:
  /usr/local/share/emacs/site-lisp/protobuf
==> Summary
🍺  /usr/local/Cellar/protobuf/3.13.0: 266 files, 19.8MB
==> Installing mysql
==> Pouring mysql-8.0.21_1.catalina.bottle.tar.gz
==> /usr/local/Cellar/mysql/8.0.21_1/bin/mysqld --initialize-insecure --user=ken
==> Caveats
We've installed your MySQL database without a root password. To secure it run:
    mysql_secure_installation

MySQL is configured to only allow connections from localhost by default

To connect run:
    mysql -uroot

To have launchd start mysql now and restart at login:
  brew services start mysql
Or, if you don't want/need a background service you can just run:
  mysql.server start
==> Summary
🍺  /usr/local/Cellar/mysql/8.0.21_1: 290 files, 291.2MB
==> `brew cleanup` has not been run in 30 days, running now...
Removing: /Users/xxxxxxxx/Library/Caches/Homebrew/gettext--0.20.2_1.catalina.bottle.tar.gz... (8.4MB)
Removing: /Users/xxxxxxxx/Library/Caches/Homebrew/libidn2--2.3.0.catalina.bottle.tar.gz... (233.6KB)
Removing: /Users/xxxxxxxx/Library/Caches/Homebrew/libunistring--0.9.10.catalina.bottle.tar.gz... (1.4MB)
Removing: /usr/local/Cellar/openssl@1.1/1.1.1g... (8,059 files, 18MB)
Removing: /Users/xxxxxxxx/Library/Caches/Homebrew/openssl@1.1--1.1.1g.catalina.bottle.tar.gz... (5.3MB)
Removing: /Users/xxxxxxxx/Library/Caches/Homebrew/tree--1.8.0.catalina.bottle.tar.gz... (49.5KB)
Removing: /Users/xxxxxxxx/Library/Caches/Homebrew/wget--1.20.3_2.catalina.bottle.tar.gz... (1.4MB)
Removing: /Users/xxxxxxxx/Library/Logs/Homebrew/tree... (64B)
Removing: /Users/xxxxxxxx/Library/Logs/Homebrew/wget... (64B)
Removing: /Users/xxxxxxxx/Library/Logs/Homebrew/libidn2... (64B)
Removing: /Users/xxxxxxxx/Library/Logs/Homebrew/libunistring... (64B)
Removing: /Users/xxxxxxxx/Library/Logs/Homebrew/gettext... (64B)
Removing: /Users/xxxxxxxx/Library/Logs/Homebrew/openssl@1.1... (64B)
Pruned 1 symbolic links and 2 directories from /usr/local
==> Caveats
==> openssl@1.1
A CA file has been bootstrapped using certificates from the system
keychain. To add additional certificates, place .pem files in
  /usr/local/etc/openssl@1.1/certs

and run
  /usr/local/opt/openssl@1.1/bin/c_rehash

openssl@1.1 is keg-only, which means it was not symlinked into /usr/local,
because macOS provides LibreSSL.

If you need to have openssl@1.1 first in your PATH run:
  echo 'export PATH="/usr/local/opt/openssl@1.1/bin:$PATH"' >> ~/.zshrc

For compilers to find openssl@1.1 you may need to set:
  export LDFLAGS="-L/usr/local/opt/openssl@1.1/lib"
  export CPPFLAGS="-I/usr/local/opt/openssl@1.1/include"

==> protobuf
Emacs Lisp files have been installed to:
  /usr/local/share/emacs/site-lisp/protobuf
==> mysql
We've installed your MySQL database without a root password. To secure it run:
    mysql_secure_installation

MySQL is configured to only allow connections from localhost by default

To connect run:
    mysql -uroot

To have launchd start mysql now and restart at login:
  brew services start mysql
Or, if you don't want/need a background service you can just run:
  mysql.server start

長々とログが出ましたが、入力待ちになったら which コマンドで mysql がインストールされたのを確認します。

(scraping) % which mysql
/usr/local/bin/mysql

/usr/local/bin/mysql にインストールされています。

MySQL の動作を確認

MySQL を起動

「mysql.server start」と入力して MySQL を起動してみます。

% mysql.server start
Starting MySQL
.. SUCCESS! 
% 

無事起動しました。

MySQL をシャットダウン

「mysql.server stop」でシャットダウンすることができます。

% mysql.server stop
Shutting down MySQL
.. SUCCESS!
%

mysqlclient をインストール

pip で mysqlclient をインストールします。

(scraping) % pip install mysqlclient
Collecting mysqlclient
  Using cached https://files.pythonhosted.org/packages/a5/e1/e5f2b231c05dc51d9d87fa5066f90d1405345c54b14b0b11a1c859020f21/mysqlclient-2.0.1.tar.gz
Installing collected packages: mysqlclient
  Running setup.py install for mysqlclient ... done
Successfully installed mysqlclient-2.0.1
WARNING: You are using pip version 19.2.3, however version 20.2.3 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
(scraping) % 

MySQLdb モジュールが使えることを確認

Python で MySQLdb モジュールがインポートできることを確認して完了です。

>>> import MySQLdb
>>>