這樣的開發環境沒問題嗎？

如果把軟體開發比喻成音樂，開發環境就是開發者的樂器。好的開發環境會讓開發過程更順利，減少使用者需要煩惱的外務；當你專注在需要研究的課題上，便能完成更好的作品。最好的開發環境，應該讓你成為更好的開發者。

由於 Python 的根基來自 Unix 文化，它周圍的工具鏈（toolchain）也深受其「do one thing, and do it well」哲學影響，著重於創建單一功能，可與其他工具互動的元件。搭配開源社群常見的「bring your own tools」理念，Python 傳統上並沒有一個「標準」的工具搭配，而是讓大家發揮創意自由組合。這同時是優點，也是詛咒——不論你的背景為何，都可以在 Python 找到習慣的配置，但是經驗較少的人就容易犯錯，用了不適合自己，甚至根本錯誤的開發環境。

講者在這個議程將根據自己參與 Python 工具鏈專案、以及觀察、建議 Python 開發者建構環境的意見，描述常見的開發狀況、常見的組合、容易混淆的工具用法，並根據這些問題提出建議，希望讓大家能夠找到有用的資訊，建構讓自己更得心應手的開發環境。

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1. Ṝᒬత։ᚙ؀ڥ
   ᔒ໰୊䆩ʁ
   

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3. https://conda.io/docs/user-guide/
   

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7. Me
   • Call me TP
   • Follow @uranusjr
   • https://uranusjr.com
   

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11. http://macdown.uranusjr.com
    

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12. https://docs.pipenv.org
    

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14. https://xkcd.com/1987/
    

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15. *NOT FINE
    

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16. Application
    Dependencies
    Tools
    Interpreters
    

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18. Application
    Dependencies
    

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19. $ python3 -m venv --prompt="project" .venv
    $ . .venv/bin/activate
    (project) $ pip install -r requirements.txt
    

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20. cffi==1.5.2
    cryptography==1.2.2
    enum34==1.1.2
    Flask==0.10.1
    gunicorn==19.4.5
    idna==2.0
    ipaddress==1.0.16
    itsdangerous==0.24
    Jinja2==2.8
    MarkupSafe==0.23
    ndg-httpsclient==0.4.0
    pyasn1==0.1.9
    pycparser==2.14
    pyOpenSSL==0.15.1
    requests==2.9.1
    six==1.10.0
    Werkzeug==0.11.4
    requests[security]
    flask
    gunicorn==19.4.5
    

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21. https://gist.github.com/datagrok/2199506
    

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23. Python? Meh.
    

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24. https://docs.pipenv.org
    

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25. Pipenv
    • No more bin/activate
    • Subshell
    • Direct binary call
    • Declared dependencies
    • Locking into actual requirements
    

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27. Application
    Dependencies
    Tools
    

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28. SUDO PIP INSTALL PIPENV
    

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29. I TOLD YOU TO USE
    VIRTUAL ENVIRONMENTS
    

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31. $ mkdir -p ~/.local/bin ~/.local/venvs
    $ python3 -m venv ~/.local/venvs/pipenv
    $ ~/.local/venvs/pipenv/bin/pip install pipenv
    $ ln -s ~/.local/venvs/pipenv/bin/pipenv ~/.local/bin
    $ pipenv --version
    pipenv, version 11.10.3
    

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32. https://github.com/mitsuhiko/pipsi
    

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33. Rules of Thumb
    • Do not use sudo. Ever.
    • Always use virtual environments
    • Use --user when desperate
    

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34. $ python3 -m ~/.local/venvs/pipenv
    

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35. Application
    Dependencies
    Tools
    Interpreters
    

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36. I MEAN
    IT COULD BE WORSE
    

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38. Linux
    • Ubuntu: use “deadsnakes” PPA
    • Compile your own otherwise
    • Discussed later
    • Be careful with the package manager
    

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39. macOS
    • Do not use System Python
    • Do not use Homebrew Python
    • Must compile your own
    

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40. Compile Your Python
    • Install some build dependencies
    • pyenv install
    • You can use shims, but I hate them
    

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41. $ python-build 3.6.5 ~/.local/pythons/3.6
    $ python-build 3.5.4 ~/.local/pythons/3.5
    $ ln -s ~/.local/pythons/3.6/python3.6 ~/.local/bin
    $ ln -s ~/.local/pythons/3.5/python3.5 ~/.local/bin
    $ ln -s ~/.local/bin/python3.6 ~/.local/bin/python3
    

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42. $ python3.5 -V
    Python 3.5.4
    $ python3 -V
    Python 3.6.5
    $ python -V
    nope
    

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43. https://github.com/uranusjr/pythonup-macos
    

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44. $ pythonup install 3.6 # Build 3.6.
    $ pythonup upgrade 3.6 # Re-install if newer.
    $ pythonup use 3.6 # Link 3.6 scripts.
    

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45. python() {
    local PYTHON="$(which python)"
    if [[ "$PYTHON" == /usr/* ]]; then
    echo "nope" >&2 | echo >/dev/null
    else
    "$PYTHON" "$@"
    fi
    }
    Hide the Default Python
    

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46. Windows
    • No global Python to worry about
    • No support from pyenv
    • Building is drastically more difficult
    

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47. https://vstinner.readthedocs.io/cpython_windows.html
    

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48. ! Just use installers from python.org?
    

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49. " At least download them automatically?
    

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50. https://github.com/uranusjr/pythonup-windows
    

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51. $ pythonup install 3.6 # Download and install 3.6.
    $ pythonup upgrade 3.6 # Re-install if newer.
    $ pythonup use 3.6 # Link 3.6 scripts.
    

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52. THE CIRCLE
    IS NOW COMPLETE
    

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53. Summary (1/3)
    • Don’t use Homebrew Python
    • Prefer self-compiling if possible
    • Don’t add things to PATH; link* them
    

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54. Summary (2/3)
    • Always use virtual environments
    • You can call scripts in venv directly
    • Link* them in PATH!
    

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55. Summary (3/3)
    • Always use virtual environments (reprise)
    • Avoid activate scripts
    • Pipfile and Pipenv abstracts away warts
    

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56. Future Work
    • A lot of unfinished stuff already
    • Differences when developing a package
    • pyproject.toml and build system declaration
    

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57. JOIN!
    

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