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diff --git a/docs/quick_tutorial/package.rst b/docs/quick_tutorial/package.rst new file mode 100644 index 000000000..94cb39fc9 --- /dev/null +++ b/docs/quick_tutorial/package.rst @@ -0,0 +1,111 @@ +============================================ +02: Python Packages for Pyramid Applications +============================================ + +Most modern Python development is done using Python packages, an approach +Pyramid puts to good use. In this step we redo "Hello World" as a minimal +Python package inside a minimal Python project. + + +Background +========== + +Python developers can organize a collection of modules and files into a +namespaced unit called a :ref:`package <python:tut-packages>`. If a directory +is on ``sys.path`` and has a special file named ``__init__.py``, it is treated +as a Python package. + +Packages can be bundled up, made available for installation, and installed +through a toolchain oriented around a ``setup.py`` file. For this tutorial, +this is all you need to know: + +- We will have a directory for each tutorial step as a *project*. + +- This project will contain a ``setup.py`` which injects the features of the + project machinery into the directory. + +- In this project we will make a ``tutorial`` subdirectory into a Python + *package* using an ``__init__.py`` Python module file. + +- We will run ``pip install -e .`` to install our project in development mode. + +In summary: + +- You'll do your development in a Python *package*. + +- That package will be part of a *project*. + + +Objectives +========== + +- Make a Python "package" directory with an ``__init__.py``. + +- Get a minimum Python "project" in place by making a ``setup.py``. + +- Install our ``tutorial`` project in development mode. + + +Steps +===== + +#. Make an area for this tutorial step: + + .. code-block:: bash + + $ cd ..; mkdir package; cd package + +#. In ``package/setup.py``, enter the following: + + .. literalinclude:: package/setup.py + +#. Make the new project installed for development then make a directory for the + actual code: + + .. code-block:: bash + + $ $VENV/bin/pip install -e . + $ mkdir tutorial + +#. Enter the following into ``package/tutorial/__init__.py``: + + .. literalinclude:: package/tutorial/__init__.py + +#. Enter the following into ``package/tutorial/app.py``: + + .. literalinclude:: package/tutorial/app.py + +#. Run the WSGI application with: + + .. code-block:: bash + + $ $VENV/bin/python tutorial/app.py + +#. Open http://localhost:6543/ in your browser. + + +Analysis +======== + +Python packages give us an organized unit of project development. Python +projects, via ``setup.py``, give us special features when our package is +installed (in this case, in local development mode, also called local editable +mode as indicated by ``-e .``). + +In this step we have a Python package called ``tutorial``. We use the same name +in each step of the tutorial, to avoid unnecessary retyping. + +Above this ``tutorial`` directory we have the files that handle the packaging +of this project. At the moment, all we need is a bare-bones ``setup.py``. + +Everything else is the same about our application. We simply made a Python +package with a ``setup.py`` and installed it in development mode. + +Note that the way we're running the app (``python tutorial/app.py``) is a bit +of an odd duck. We would never do this unless we were writing a tutorial that +tries to capture how this stuff works one step at a time. It's generally a bad +idea to run a Python module inside a package directly as a script. + +.. seealso:: :ref:`Python Packages <python:tut-packages>` and `Working in + "Development Mode" + <https://packaging.python.org/en/latest/distributing/#working-in-development-mode>`_. |
