Before you begin
This tutorial assumes that you have already followed the steps in :ref:`installing_chapter`, except do not create a virtual environment or install Pyramid. Thereby you will satisfy the following requirements.
- A Python interpreter is installed on your operating system.
- You've satisfied the :ref:`requirements-for-installing-packages`.
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
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.
$ cd ~ $ cookiecutter gh:Pylons/pyramid-cookiecutter-alchemy --checkout master
c:\> cd \ c:\> cookiecutter gh:Pylons/pyramid-cookiecutter-alchemy --checkout master
On all operating systems
If prompted for the first item, accept the default
yes by hitting return.
You've cloned ~/.cookiecutters/pyramid-cookiecutter-alchemy before. Is it okay to delete and re-clone it? [yes]: yes project_name [Pyramid Scaffold]: myproj repo_name [myproj]: tutorial
Change directory into your newly created project
$ cd tutorial
c:\> 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.
$ export VENV=~/tutorial
c:\tutorial> set VENV=c:\tutorial
Create a virtual environment
$ python3 -m venv $VENV
Each version of Python uses different paths, so you will need to adjust the path to the command for your Python version. Recent versions of the Python 3 installer for Windows now install a Python launcher.
c:\tutorial> c:\Python27\Scripts\virtualenv %VENV%
c:\tutorial> python -m venv %VENV%
Upgrade packaging tools in the virtual environment
$ $VENV/bin/pip install --upgrade pip setuptools
c:\tutorial> %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.
$ $VENV/bin/pip install -e ".[testing]"
c:\tutorial> %VENV%\Scripts\pip install -e ".[testing]"
On all operating systems
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 Jinja2-2.8 Mako-1.0.6 MarkupSafe-0.23 \ PasteDeploy-1.5.2 Pygments-2.1.3 SQLAlchemy-1.1.4 WebOb-1.6.3 \ WebTest-2.0.24 beautifulsoup4-4.5.1 coverage-4.2 py-1.4.32 pyramid-1.7.3 \ pyramid-debugtoolbar-3.0.5 pyramid-jinja2-2.7 pyramid-mako-1.0.2 \ pyramid-tm-1.1.1 pytest-3.0.5 pytest-cov-2.4.0 repoze.lru-0.6 six-1.10.0 \ transaction-2.0.3 translationstring-1.3 tutorial venusian-1.0 \ waitress-1.0.1 zope.deprecation-4.2.0 zope.interface-4.3.3 \ zope.sqlalchemy-0.7.7
Testing requirements are defined in our project's
setup.py file, in the
.. literalinclude:: src/installation/setup.py :language: python :lineno-match: :lines: 24-28
.. literalinclude:: src/installation/setup.py :language: python :lineno-match: :lines: 48-50
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.
$ $VENV/bin/py.test -q
c:\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
:term:`coverage` information, exposing which lines of your project are covered by the
We've already installed the
pytest-cov package into our virtual
environment, so we can run the tests with coverage.
$ $VENV/bin/py.test --cov --cov-report=term-missing
c:\tutorial> %VENV%\Scripts\py.test --cov --cov-report=term-missing
If successful, you will see output something like this:
======================== test session starts ======================== platform Python 3.6.0, pytest-3.0.5, py-1.4.31, pluggy-0.4.0 rootdir: /Users/stevepiercy/tutorial, inifile: plugins: cov-2.4.0 collected 2 items tutorial/tests.py .. ------------------ coverage: platform Python 3.6.0 ------------------ 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 cookiecutter defaults
Cookiecutters include configuration defaults for
py.test and test coverage.
These configuration files are
.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.
$ $VENV/bin/py.test --cov=tutorial tutorial/tests.py -q
c:\tutorial> %VENV%\Scripts\py.test --cov=tutorial tutorial\tests.py -q
py.test follows :ref:`conventions for Python test discovery
<pytest:test discovery>`, and the configuration defaults from the cookiecutter
py.test where to find the module on which we want to run tests and
.. seealso:: See py.test's documentation for :ref:`pytest:usage` or invoke ``py.test -h`` to see its full set of options.
Initializing the database
We need to use the
initialize_tutorial_db :term:`console script` to
initialize our database.
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
Type the following command, making sure you are still in the
directory (the directory with a
development.ini in it):
$ $VENV/bin/initialize_tutorial_db development.ini
c:\tutorial> %VENV%\Scripts\initialize_tutorial_db development.ini
The output to your console should be something like this:
2016-12-18 21:30:08,675 INFO [sqlalchemy.engine.base.Engine:1235][MainThread] SELECT CAST('test plain returns' AS VARCHAR(60)) AS anon_1 2016-12-18 21:30:08,675 INFO [sqlalchemy.engine.base.Engine:1236][MainThread] () 2016-12-18 21:30:08,676 INFO [sqlalchemy.engine.base.Engine:1235][MainThread] SELECT CAST('test unicode returns' AS VARCHAR(60)) AS anon_1 2016-12-18 21:30:08,676 INFO [sqlalchemy.engine.base.Engine:1236][MainThread] () 2016-12-18 21:30:08,676 INFO [sqlalchemy.engine.base.Engine:1140][MainThread] PRAGMA table_info("models") 2016-12-18 21:30:08,676 INFO [sqlalchemy.engine.base.Engine:1143][MainThread] () 2016-12-18 21:30:08,677 INFO [sqlalchemy.engine.base.Engine:1140][MainThread] CREATE TABLE models ( id INTEGER NOT NULL, name TEXT, value INTEGER, CONSTRAINT pk_models PRIMARY KEY (id) ) 2016-12-18 21:30:08,677 INFO [sqlalchemy.engine.base.Engine:1143][MainThread] () 2016-12-18 21:30:08,678 INFO [sqlalchemy.engine.base.Engine:719][MainThread] COMMIT 2016-12-18 21:30:08,679 INFO [sqlalchemy.engine.base.Engine:1140][MainThread] CREATE UNIQUE INDEX my_index ON models (name) 2016-12-18 21:30:08,679 INFO [sqlalchemy.engine.base.Engine:1143][MainThread] () 2016-12-18 21:30:08,679 INFO [sqlalchemy.engine.base.Engine:719][MainThread] COMMIT 2016-12-18 21:30:08,681 INFO [sqlalchemy.engine.base.Engine:679][MainThread] BEGIN (implicit) 2016-12-18 21:30:08,682 INFO [sqlalchemy.engine.base.Engine:1140][MainThread] INSERT INTO models (name, value) VALUES (?, ?) 2016-12-18 21:30:08,682 INFO [sqlalchemy.engine.base.Engine:1143][MainThread] ('one', 1) 2016-12-18 21:30:08,682 INFO [sqlalchemy.engine.base.Engine:719][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
Start the application
Start the application. See :ref:`what_is_this_pserve_thing` for more
$ $VENV/bin/pserve development.ini --reload
c:\tutorial> %VENV%\Scripts\pserve development.ini --reload
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 :ref:`debug_toolbar`. It allows you to get information about your application while you develop.
alchemy cookiecutter has made for you
Creating a project using the
alchemy cookiecutter makes the following
- You are willing to use SQLite for persistent storage, although almost any SQL database could be used with SQLAlchemy.
- You are willing to use :term:`SQLAlchemy` for a database access tool.
- You are willing to use :term:`URL dispatch` to map URLs to code.
- You want to use zope.sqlalchemy, pyramid_tm, and the transaction packages to scope sessions to requests.
- You want to use pyramid_jinja2 to render your templates. Different templating engines can be used, but we had to choose one to make this tutorial. See :ref:`available_template_system_bindings` for some options.