Installation¶

Before you begin¶

This tutorial assumes that you have already followed the steps in Installing Pyramid, except do not create a virtual environment or install Pyramid. Thereby you will satisfy the following requirements.

We will use a cookiecutter to create a Python package project from a Python package project template. See Cookiecutter Installation for instructions.

Generate a Pyramid project from a cookiecutter¶

We will create a Pyramid project in your home directory for Unix or at the root for Windows. It is assumed you know the path to where you installed cookiecutter. Issue the following commands and override the defaults in the prompts as follows.

On Unix¶

cd ~


On Windows¶

cd \


On all operating systems¶

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

You've cloned ~/.cookiecutters/pyramid-cookiecutter-theone before.
Is it okay to delete and re-clone it? [yes]: yes
project_name [Pyramid Scaffold]: myproj
repo_name [myproj]: tutorial
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]: 3


Change directory into your newly created project¶

On Unix¶

cd tutorial


On Windows¶

cd tutorial


Set and use a VENV environment variable¶

We will set the VENV environment variable to the absolute path of the virtual environment, and use it going forward.

On Unix¶

export VENV=~/tutorial


On Windows¶

set VENV=c:\tutorial


Create a virtual environment¶



On Windows¶

%VENV%\Scripts\pip install --upgrade pip setuptools


Installing the project in development mode¶

In order to do development on the project easily, you must "register" the project as a development egg in your workspace. We will install testing requirements at the same time. We do so with the following command.



On Windows¶

%VENV%\Scripts\pytest -q


For a successful test run, you should see output that ends like this:

.
1 passed in 0.24 seconds


Expose test coverage information¶

You can run the pytest command to see test coverage information. This runs the tests in the same way that pytest does, but provides additional coverage information, exposing which lines of your project are covered by the tests.

We've already installed the pytest-cov package into our virtual environment, so we can run the tests with coverage.



On Windows¶

%VENV%\Scripts\pytest --cov=tutorial tutorial\tests.py -q


pytest follows conventions for Python test discovery, and the configuration defaults from the cookiecutter tell pytest where to find the module on which we want to run tests and coverage.

See pytest's documentation for Usage and Invocations or invoke pytest -h to see its full set of options.

Start the application¶

Start the application. See What Is This pserve Thing for more information on pserve.

On Unix¶

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


On Windows¶

%VENV%\Scripts\pserve development.ini --reload


Note

Your OS firewall, if any, may pop up a dialog asking for authorization to allow python to accept incoming network connections.

If successful, you will see something like this on your console:

Starting subprocess with file monitor
Starting server in PID 44078.
Serving on http://localhost:6543
Serving on http://localhost:6543


This means the server is ready to accept requests.

Visit the application in a browser¶

In a browser, visit http://localhost:6543/. You will see the generated application's default page.

One thing you'll notice is the "debug toolbar" icon on right hand side of the page. You can read more about the purpose of the icon at The Debug Toolbar. It allows you to get information about your application while you develop.

Decisions the cookiecutter backend option zodb has made for you¶

When creating a project and selecting the backend option of zodb, the cookiecutter makes the following assumptions:

Note

Pyramid supports any persistent storage mechanism (e.g., an SQL database or filesystem files). It also supports an additional mechanism to map URLs to code (URL dispatch). However, for the purposes of this tutorial, we'll only be using traversal and ZODB.