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.

Create directory to contain the project

We need a workspace for our project files.

On UNIX

$ mkdir ~/pyramidtut

On Windows

c:\> mkdir pyramidtut

Create and use a virtual Python environment

Next let's create a virtual environment workspace for our project. We will use the VENV environment variable instead of the absolute path of the virtual environment.

On UNIX

$ export VENV=~/pyramidtut
$ python3 -m venv $VENV

On Windows

c:\> set VENV=c:\pyramidtut

Each version of Python uses different paths, so you will need to adjust the path to the command for your Python version.

Python 2.7:

c:\> c:\Python27\Scripts\virtualenv %VENV%

Python 3.5:

c:\> c:\Python35\Scripts\python -m venv %VENV%

Upgrade pip and setuptools in the virtual environment

On UNIX

$ $VENV/bin/pip install --upgrade pip setuptools

On Windows

c:\> %VENV%\Scripts\pip install --upgrade pip setuptools

Install Pyramid into the virtual Python environment

On UNIX

$ $VENV/bin/pip install "pyramid==1.8.dev0"

On Windows

c:\> %VENV%\Scripts\pip install "pyramid==1.8.dev0"

Change directory to your virtual Python environment

Change directory to the pyramidtut directory, which is both your workspace and your virtual environment.

On UNIX

$ cd pyramidtut

On Windows

c:\> cd pyramidtut

Making a project

Your next step is to create a project. For this tutorial, we will use the scaffold named zodb, which generates an application that uses ZODB and traversal.

Pyramid supplies a variety of scaffolds to generate sample projects. We will use pcreate, a script that comes with Pyramid, to create our project using a scaffold.

By passing zodb into the pcreate command, the script creates the files needed to use ZODB. By passing in our application name tutorial, the script inserts that application name into all the required files.

The below instructions assume your current working directory is "pyramidtut".

On UNIX

$ $VENV/bin/pcreate -s zodb tutorial

On Windows

c:\pyramidtut> %VENV%\Scripts\pcreate -s zodb tutorial

Note

If you are using Windows, the zodb scaffold may not deal gracefully with installation into a location that contains spaces in the path. If you experience startup problems, try putting both the virtual environment and the project into directories that do not contain spaces in their paths.

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 using the pip install -e . command. In order to do so, change directory to the tutorial directory that you created in Making a project, and run the pip install -e . command using the virtual environment Python interpreter.

On UNIX

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

On Windows

c:\pyramidtut> cd tutorial
c:\pyramidtut\tutorial> %VENV%\Scripts\pip install -e .

The console will show pip checking for packages and installing missing packages. Success executing this command will show a line like the following:

Successfully installed BTrees-4.2.0 Chameleon-2.24 Mako-1.0.4 \
MarkupSafe-0.23 Pygments-2.1.3 ZConfig-3.1.0 ZEO-4.2.0b1 ZODB-4.2.0 \
ZODB3-3.11.0 mock-2.0.0 pbr-1.8.1 persistent-4.1.1 pyramid-chameleon-0.3 \
pyramid-debugtoolbar-2.4.2 pyramid-mako-1.0.2 pyramid-tm-0.12.1 \
pyramid-zodbconn-0.7 six-1.10.0 transaction-1.4.4 tutorial waitress-0.8.10 \
zc.lockfile-1.1.0 zdaemon-4.1.0 zodbpickle-0.6.0 zodburi-2.0

Install testing requirements

In order to run tests, we need to install the testing requirements. This is done through our project's setup.py file, in the tests_require and extras_require stanzas, and by issuing the command below for your operating system.

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tests_require = [
    'WebTest >= 1.3.1',  # py3 compat
    'pytest',  # includes virtualenv
    'pytest-cov',
    ]
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      extras_require={
          'testing': tests_require,
      },

On UNIX

$ $VENV/bin/pip install -e ".[testing]"

On Windows

c:\pyramidtut\tutorial> %VENV%\Scripts\pip install -e ".[testing]"

Run the tests

After you've installed the project in development mode as well as the testing requirements, you may run the tests for the project.

On UNIX

$ $VENV/bin/py.test tutorial/tests.py -q

On Windows

c:\pyramidtut\tutorial> %VENV%\Scripts\py.test tutorial\tests.py -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 py.test command to see test coverage information. This runs the tests in the same way that py.test 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 UNIX

$ $VENV/bin/py.test --cov=tutorial --cov-report=term-missing tutorial/tests.py

On Windows

c:\pyramidtut\tutorial> %VENV%\Scripts\py.test --cov=tutorial \
    --cov-report=term-missing tutorial\tests.py

If successful, you will see output something like this:

======================== test session starts ========================
platform Python 3.5.1, pytest-2.9.1, py-1.4.31, pluggy-0.3.1
rootdir: /Users/stevepiercy/projects/pyramidtut/tutorial, inifile:
plugins: cov-2.2.1
collected 1 items

tutorial/tests.py .
------------------ coverage: platform Python 3.5.1 ------------------
Name                   Stmts   Miss  Cover   Missing
----------------------------------------------------
tutorial/__init__.py      12      7    42%   7-8, 14-18
tutorial/models.py        10      6    40%   9-14
tutorial/tests.py         12      0   100%
tutorial/views.py          4      0   100%
----------------------------------------------------
TOTAL                     38     13    66%

===================== 1 passed in 0.31 seconds ======================

Our package doesn't quite have 100% test coverage.

Start the application

Start the application.

On UNIX

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

On Windows

c:\pyramidtut\tutorial> %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 95736.
serving on http://127.0.0.1:6543

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 zodb scaffold has made for you

Creating a project using the zodb scaffold makes the following assumptions:

  • You are willing to use ZODB as persistent storage.
  • You are willing to use traversal to map URLs to code.

Note

Pyramid supports any persistent storage mechanism (e.g., a 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.