Prelude: Quick Project Startup with Cookiecutters

To ease the process of getting started on a project, the Pylons Project provides a cookiecutter that generates sample Pyramid projects from project templates. The cookiecutter will install Pyramid and its dependencies as well. We will still cover many topics of web application development using Pyramid, but it's good to know of this facility. This prelude will demonstrate how to get a working Pyramid web application running via cookiecutter.

Objectives

• Use a cookiecutter to make a new project.

• Start up a Pyramid application and visit it in a web browser.

Steps

1. Install cookiecutter into your virtual environment.

   $VENV/bin/pip install cookiecutter
   

2. Let's use the cookiecutter pyramid-cookiecutter-starter to create a starter Pyramid project in the current directory, entering values at the prompts as shown below for the following command.

   $VENV/bin/cookiecutter gh:Pylons/pyramid-cookiecutter-starter --checkout 2.0-branch
   

   If prompted for the first item, accept the default yes by hitting return.

   You've cloned ~/.cookiecutters/pyramid-cookiecutter-starter before.
   Is it okay to delete and re-clone it? [yes]: yes
   project_name [Pyramid Scaffold]: cc_starter
   repo_name [cc_starter]: cc_starter
   Select template_language:
   1 - jinja2
   2 - chameleon
   3 - mako
   Choose from 1, 2, 3 [1]: 1
   Select backend:
   1 - none
   2 - sqlalchemy
   3 - zodb
   Choose from 1, 2, 3 [1]: 1
   

3. We then run through the following commands.

   # Change directory into your newly created project.
   cd cc_starter
   # Create a new virtual environment...
   python3 -m venv env
   # ...where we upgrade packaging tools...
   env/bin/pip install --upgrade pip setuptools
   # ...and into which we install our project.
   env/bin/pip install -e .
   

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

   env/bin/pserve development.ini --reload
   

   On start up, pserve logs some output:

   Starting monitor for PID 60461.
   Starting server in PID 60461.
   Serving on http://localhost:6543
   Serving on http://localhost:6543
   

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

Analysis

Rather than starting from scratch, a cookiecutter can make it easy to get a Python project containing a working Pyramid application.

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).