Aaron Hung

Aaron Hung

Life surfing

© 2019

Developing Python Packages
    Dec 22, 2021

    Introduce how to develop python package with easy framework

    Developing Python Packages

    Lesson 1

    • reuse
    • key function up to date

    • sharing

    • Terms
      • script : python file
      • package : a directory full of python code to be imported, such as numpy
      • subpackage, such as numpy.random
      • Module : a python file inside a package which stores the package code
      • library : a package or collection of package
    • Directory tree of package
      • simplemodule.py
      • init.py :

    • from scrip to package

    Documentation

    • Function
    • Class
    • Class method

    • docstring templates

    ` pyment -w -o google textanalysis.py `

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    def inches_to_feet(x, reverse=False):
    """Convert lengths between inches and feet.

    Parameters
    ----------
    x : numpy.ndarray
        Lengths in feet.
    reverse : bool, optional
        If true this function converts from feet to inches 
        instead of the default behavior of inches to feet. 
        (Default value = False)

    Returns
    -------
    numpy.ndarray
    """
    if reverse:
        return x * INCHES_PER_FOOT
    else:
        return x / INCHES_PER_FOOT

    Structuring imports

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    import mysklearn.preprocessing.normalize

from mysklearn import preprocessing


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    """User-facing functions."""
from impyrial.length.core import (
    UNITS,
    inches_to_feet,
    inches_to_yards
)

    Lesson 2 : install your own package

    • Package directory structure

    • setup.py

    • find_package

    [image:3ECF5F03-2C74-4140-9642-8F67E1DFE5B9-23475-00000614EA62826E/截圖 2021-12-20 下午11.15.26.png]

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    pip install -e .

    dealing with dependencies

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    pip freeze > requirements.txt

pip install - r requirements.txt

    Including licences and writing READMEs

    • license
      • to give others permission to use your code
    • README
      • Title
      • Description
      • Installation
      • Usage examples
      • Contributing
      • License

    • MANIFEST.in
      • List all the extra files to include in your package distribution
      • include README.md
      • include LICENSE

    Publishing your package

    • PyPI
    • Distributions
      • source distribution : a distribution package which is mostly your source code
      • wheel distribution : a distribution package which has been processed to make it faster to install
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    python setup.py sdist bdist_wheel

    • upload ```python twine upload dist/*

    twine upload -r testpypi dist/*

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    ## Lesson 3 : Testing your package
* Writing tests

![](https://i.imgur.com/jiPxE8c.png)


* Organizing tests inside your package

![](https://i.imgur.com/OSHL0IY.png)

    pytest

    會執行所有test開頭的module

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![](https://i.imgur.com/BPigsJn.png)


### Testing your package with different environments
* Testing multiple versions of Python
	* tox
		* tox.ini
			![](https://i.imgur.com/vALbdCL.png)

	
			![](https://i.imgur.com/bTIJBB0.png)

			
            ![](https://i.imgur.com/0PpE2eL.png)


### keeping your package stylish
* standard python style is described in PEP8
* a style guide dictates how code should be laid out
	* flake8
` flake8 features.py `

![](https://i.imgur.com/73NKpmS.png)

	* breaking the rule on purpose

![](https://i.imgur.com/AfsVTH7.png)

	* find/ignore specific rule
![](https://i.imgur.com/pYW9znU.png)


* setup.cfg

![](https://i.imgur.com/QULqZxU.png)

    [flake8]

    Ignore F401 violations in the main init.py file

    per-file-ignores =

    impyrial/init.py : F401

    Ignore all violations in the tests directoory

    exclude = tests/*

    ```

    Lesson 4: Rapid Package Development

    • Faster package development with templates
    • cookiecutter ` cookiecutter https://github.com/audreyr/cookiecutter-pypackage `

    version numbers and history

    • CONTRIBUTING.md
    • HISTORY.md
      • e.g. NumPy release notes

        History

        0.3.0

        Changed

        • ….

          Deprecated

        • …

          0.2.1

          Fixed

        • …

          0.2.0

          Added

        • ….

          Deprecated

        • …
        • …
    • Version number
      • setup.py
      • init.py
      • bumpversion
        • major
        • minor
        • patch

    Makefiles and classifier

    • Classifiers
      • inside setup.py of mysklearn

    • Makefiles
      • used to automate parts of building your package
        • make clean
        • make test
        • make dist

    • Advanced:
      • UT in DS
      • Package website : ReadtheDocs and Sphinx