Prelude: Quick Project Startup with Scaffolds

To ease the process of getting started, Pyramid provides scaffolds that generate sample projects from templates in Pyramid and Pyramid add-ons.

Background

We're going to cover a lot in this tutorial, focusing on one topic at a time and writing everything from scratch. As a warm up, though, it sure would be nice to see some pixels on a screen.

Like other web development frameworks, Pyramid provides a number of "scaffolds" that generate working Python, template, and CSS code for sample applications. In this step we'll use a built-in scaffold to let us preview a Pyramid application, before starting from scratch on Step 1.

Objectives

  • Use Pyramid's pcreate command to list scaffolds and make a new project.
  • Start up a Pyramid application and visit it in a web browser.

Steps

  1. Pyramid's pcreate command can list the available scaffolds:

    $ $VENV/bin/pcreate --list
Available scaffolds:
  alchemy:  Pyramid project using SQLAlchemy, SQLite, URL dispatch, and Jinja2
  starter:  Pyramid starter project using URL dispatch and Chameleon
  zodb:     Pyramid project using ZODB, traversal, and Chameleon

  2. Tell pcreate to use the starter scaffold to make our project:

    $ $VENV/bin/pcreate --scaffold starter scaffolds

  3. Install our project in editable mode for development in the current directory:

    $ cd scaffolds
$ $VENV/bin/pip install -e .

  4. Start up the application by pointing Pyramid's pserve command at the project's (generated) configuration file:

    $ $VENV/bin/pserve development.ini --reload

    On start up, pserve logs some output:

    Starting subprocess with file monitor
Starting server in PID 72213.
Starting HTTP server on http://0.0.0.0:6543

  5. Open http://localhost:6543/ in your browser.

Analysis

Rather than starting from scratch, pcreate can make getting a Python project containing a Pyramid application a quick matter. Pyramid ships with a few scaffolds. But installing a Pyramid add-on can give you new scaffolds from that add-on.

pserve is Pyramid's application runner, separating operational details from your code. When you install Pyramid, a small command program called pserve is written to your bin directory. This program is an executable Python module. It is passed a configuration file (in this case, development.ini).