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.
- A Python interpreter is installed on your operating system.
- You've satisfied the 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
Install cookiecutter¶
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 ~
$ cookiecutter gh:Pylons/pyramid-cookiecutter-alchemy --checkout 1.8-branch
On Windows¶
c:\> cd \
c:\> cookiecutter gh:Pylons/pyramid-cookiecutter-alchemy --checkout 1.8-branch
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¶
On UNIX¶
$ cd tutorial
On Windows¶
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.
On UNIX¶
$ export VENV=~/tutorial
On Windows¶
c:\tutorial> set VENV=c:\tutorial
Create a virtual environment¶
On UNIX¶
$ python3 -m venv $VENV
On Windows¶
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.
Python 2.7:
c:\tutorial> c:\Python27\Scripts\virtualenv %VENV%
Python 3.6:
c:\tutorial> python -m venv %VENV%
Upgrade packaging tools in the virtual environment¶
On UNIX¶
$ $VENV/bin/pip install --upgrade pip setuptools
On Windows¶
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.
On UNIX¶
$ $VENV/bin/pip install -e ".[testing]"
On Windows¶
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 tests_require
and extras_require
stanzas.
22 23 24 25 26 | tests_require = [
'WebTest >= 1.3.1', # py3 compat
'pytest',
'pytest-cov',
]
|
46 47 48 | extras_require={
'testing': tests_require,
},
|
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:\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:\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 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:\tutorial> %VENV%\Scripts\py.test --cov=tutorial tutorial\tests.py -q
py.test follows conventions for Python test discovery, and the configuration defaults from the cookiecutter
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:\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
(models
).
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¶
c:\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 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 alchemy
cookiecutter has made for you¶
Creating a project using the alchemy
cookiecutter makes the following
assumptions:
- You are willing to use SQLite for persistent storage, although almost any SQL database could be used with SQLAlchemy.
- You are willing to use SQLAlchemy for a database access tool.
- You are willing to use 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 Available Add-On Template System Bindings for some options.
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.