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==1.7.3"

On Windows

c:\> %VENV%\Scripts\pip install "pyramid==1.7.3"

Install SQLite3 and its development packages

If you used a package manager to install your Python or if you compiled your Python from source, then you must install SQLite3 and its development packages. If you downloaded your Python as an installer from https://www.python.org, then you already have it installed and can skip this step.

If you need to install the SQLite3 packages, then, for example, using the Debian system and apt-get, the command would be the following:

$ sudo apt-get install libsqlite3-dev

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 alchemy which generates an application that uses SQLAlchemy and URL dispatch.

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 alchemy into the pcreate command, the script creates the files needed to use SQLAlchemy. By passing in our application name tutorial, the script inserts that application name into all the required files. For example, pcreate creates the initialize_tutorial_db in the pyramidtut/bin directory.

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

On UNIX

$ $VENV/bin/pcreate -s alchemy tutorial

On Windows

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

Note

If you are using Windows, the alchemy 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 Chameleon-2.24 Mako-1.0.4 MarkupSafe-0.23 \
Pygments-2.1.3 SQLAlchemy-1.0.12 pyramid-chameleon-0.3 \
pyramid-debugtoolbar-2.4.2 pyramid-mako-1.0.2 pyramid-tm-0.12.1 \
transaction-1.4.4 tutorial waitress-0.8.10 zope.sqlalchemy-0.7.6

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. The following commands provide options to py.test that specify the module for which its tests shall be run, and to run py.test in quiet mode.

On UNIX

$ $VENV/bin/py.test -q

On Windows

c:\pyramidtut\tutorial> %VENV%\Scripts\py.test -q

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

..
2 passed in 0.44 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 --cov-report=term-missing

On Windows

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

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 2 items

tutorial/tests.py ..
------------------ coverage: platform Python 3.5.1 ------------------
Name                               Stmts   Miss  Cover   Missing
----------------------------------------------------------------
tutorial/__init__.py                   8      6    25%   7-12
tutorial/models/__init__.py           22      0   100%
tutorial/models/meta.py                5      0   100%
tutorial/models/mymodel.py             8      0   100%
tutorial/routes.py                     3      2    33%   2-3
tutorial/scripts/__init__.py           0      0   100%
tutorial/scripts/initializedb.py      26     16    38%   22-25, 29-45
tutorial/views/__init__.py             0      0   100%
tutorial/views/default.py             12      0   100%
tutorial/views/notfound.py             4      2    50%   6-7
----------------------------------------------------------------
TOTAL                                 88     26    70%
===================== 2 passed in 0.57 seconds ======================

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

Test and coverage scaffold defaults

Scaffolds include configuration defaults for py.test and test coverage. These configuration files are pytest.ini and .coveragerc, located at the root of your package. Without these defaults, we would need to specify the path to the module on which we want to run tests and coverage.

On UNIX

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

On Windows

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

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

See also

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

Initializing the database

We need to use the initialize_tutorial_db console script to initialize our database.

Note

The initialize_tutorial_db command does not perform a migration, but rather it simply creates missing tables and adds some dummy data. If you already have a database, you should delete it before running initialize_tutorial_db again.

Type the following command, making sure you are still in the tutorial directory (the directory with a development.ini in it):

On UNIX

$ $VENV/bin/initialize_tutorial_db development.ini

On Windows

c:\pyramidtut\tutorial> %VENV%\Scripts\initialize_tutorial_db development.ini

The output to your console should be something like this:

2016-05-22 04:03:28,888 INFO  [sqlalchemy.engine.base.Engine:1192][MainThread] SELECT CAST('test plain returns' AS VARCHAR(60)) AS anon_1
2016-05-22 04:03:28,888 INFO  [sqlalchemy.engine.base.Engine:1193][MainThread] ()
2016-05-22 04:03:28,888 INFO  [sqlalchemy.engine.base.Engine:1192][MainThread] SELECT CAST('test unicode returns' AS VARCHAR(60)) AS anon_1
2016-05-22 04:03:28,889 INFO  [sqlalchemy.engine.base.Engine:1193][MainThread] ()
2016-05-22 04:03:28,890 INFO  [sqlalchemy.engine.base.Engine:1097][MainThread] PRAGMA table_info("models")
2016-05-22 04:03:28,890 INFO  [sqlalchemy.engine.base.Engine:1100][MainThread] ()
2016-05-22 04:03:28,892 INFO  [sqlalchemy.engine.base.Engine:1097][MainThread]
CREATE TABLE models (
    id INTEGER NOT NULL,
    name TEXT,
    value INTEGER,
    CONSTRAINT pk_models PRIMARY KEY (id)
)


2016-05-22 04:03:28,892 INFO  [sqlalchemy.engine.base.Engine:1100][MainThread] ()
2016-05-22 04:03:28,893 INFO  [sqlalchemy.engine.base.Engine:686][MainThread] COMMIT
2016-05-22 04:03:28,893 INFO  [sqlalchemy.engine.base.Engine:1097][MainThread] CREATE UNIQUE INDEX my_index ON models (name)
2016-05-22 04:03:28,893 INFO  [sqlalchemy.engine.base.Engine:1100][MainThread] ()
2016-05-22 04:03:28,894 INFO  [sqlalchemy.engine.base.Engine:686][MainThread] COMMIT
2016-05-22 04:03:28,896 INFO  [sqlalchemy.engine.base.Engine:646][MainThread] BEGIN (implicit)
2016-05-22 04:03:28,897 INFO  [sqlalchemy.engine.base.Engine:1097][MainThread] INSERT INTO models (name, value) VALUES (?, ?)
2016-05-22 04:03:28,897 INFO  [sqlalchemy.engine.base.Engine:1100][MainThread] ('one', 1)
2016-05-22 04:03:28,898 INFO  [sqlalchemy.engine.base.Engine:686][MainThread] COMMIT

Success! You should now have a tutorial.sqlite file in your current working directory. This is an SQLite database with a single table defined in it (models).

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 82349.
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 alchemy scaffold has made for you

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

Note

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