Pipenv - Melbourne Python User Group (MPUG)

August 2018 presentation introducing the Pipenv dependency management tool.

Transcript

1. pipenv
   The Future of Python Dependency Management
   

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2. Rory Hart
   Biarri Rail
   Railroad Planning & Scheduling Software
   CTO - Biarri Rail
   @falican
   

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3. Hiring
   Senior Fullstack Python + Javascript
   

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4. Acknowledgement
   This talk liberally borrows from Kenneth Reitz’s PyCon talk of the same name.
   Follow @kennethreitz - creator of Requests: HTTP for Humans
   

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5. The Current State of Things
   

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6. A lot of tooling for newbies
   • pip
   • requirements.txt
   • requirements_dev.txt
   • requirements_*.txt
   • virtualenv
   • + virtualenvwrapper
   • pyenv
   • + pyenv-virtualenv
   • + a bunch more plugins …
   • anaconda
   

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7. This tooling has a missing feature
   Management of “transitive dependencies”.
   A B C
   A C
   

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8. Why do we need this?
   $ pip install requests
   Collecting requests
   Collecting urllib3<1.24,>=1.21.1 (from requests)
   Collecting certifi>=2017.4.17 (from requests)
   Collecting idna<2.8,>=2.5 (from requests)
   Collecting chardet<3.1.0,>=3.0.2 (from requests)
   Installing collected packages: urllib3, certifi, idna, chardet, requests
   Successfully installed certifi-2018.4.16 chardet-3.0.4 idna-2.6 requests-2.19.1 urllib3-1.23
   $ pip install requests
   Collecting requests
   Collecting urllib3<1.24,>=1.21.1 (from requests)
   Collecting certifi>=2017.4.17 (from requests)
   Collecting idna<2.8,>=2.5 (from requests)
   Collecting chardet<3.1.0,>=3.0.2 (from requests)
   Installing collected packages: urllib3, certifi, idna, chardet, requests
   Successfully installed certifi-2018.4.16 chardet-3.0.4 idna-2.7 requests-2.19.1 urllib3-1.23
   

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9. But pip has this feature right?
   Sort of . . .
   $ pip freeze > requirements.txt
   $ cat requirements.txt
   certifi==2018.4.16
   chardet==3.0.4
   idna==2.7
   requests==2.19.1
   urllib3==1.23
   But this mixes “what I want installed” with ”what I need installed”.
   

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10. So we have two problems in Python
    1. Managing application dependencies is complex for newbies.
    2. Dependency management could be better.
    

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11. A solution is at hand
    

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12. What do other languages do?
    Nodejs: yarn & npm (lockfile)
    PHP: Composer (lockfile)
    Rust: Cargo (lockfile)
    Ruby: Bundler (lockfile)
    

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13. $ cat Pipfile
    [[source]]
    url = "https://pypi.org/simple"
    verify_ssl = true
    name = "pypi"
    [packages]
    requests = "*”
    [dev-packages]
    [requires]
    python_version = "3.6"
    A new standard that will
    eventually be supported by pip.
    https://github.com/pypa/pipfile
    Pipfile
    

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14. Pipfile.lock
    

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16. Already usable with pipenv
    Officially recommended tool on python.org.
    Automates virtualenv.
    Simplifies different python versions (with pyenv).
    Ensures deterministic builds!
    

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17. Demo Time!
    

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18. Questions?
    

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