Thursday, October 18, 2012

Python Web Frameworks PEP8 Consistency

The code is read much more often than it is written. The PEP8 guidelines are intended to improve the readability of code. Readability counts, no doubt, but readability consistency is important, it is equally important to know when to be inconsistent. The report below makes excuse for the following:
E501 line too long (> 79 characters)
E231 missing whitespace after ',:'
W291 trailing whitespace
W293 blank line contains whitespace
In this post we will take a look at web frameworks source code readability. The ratio between a web framework total python source lines to PEP8 errors found represents PEP8 error rate in respectful framework:
  1. bottle
  2. cherrypy
  3. circuits
  4. django
  5. falcon
  6. flask
  7. pyramid
  8. pysi
  9. tornado
  10. turbogears
  11. web.py
  12. web2py
  13. webapp2
  14. wheezy.web
The source code is hosted on bitbucket, let clone it into some directory and setup virtual environment (this will download source code per framework listed above).
hg clone https://bitbucket.org/akorn/helloworld
cd helloworld/04-pep8 && make env up
The make file has a target for each metric, so in order to gather pep8 count issue make pep8, or make count to count total lines.

Monday, October 15, 2012

Python Web Reverse URLs Benchmark

How fast python web frameworks reverse urls? While routing is a mapping of incoming request to a handler, url reverse function is designed to build urls for those handlers. A web page may have a number of urls from few dozen to hundreds... all related to your web site (e.g. links between related pages, tag cloud, most viewed posts, etc). A typical web application usually has deal with the following reverse url use cases:
  • Static: the URL path is fixed and never changes, e.g. https://bitbucket.org/explore.
  • Merge: the URL path is constructed dynamically, some information is taken from URL. A `user page` shows repositories. In this case a list of user repositories will be constructed as merge of information that came from URL (user name) and repository name.
  • Route: the URL path is constructed dynamically, all information can be taken from URL. A `repository page` displays a number of features: downloads, source, etc. Those links include current route information (user name and repository name).
We will examine all reverse url use cases mentioned above with... a trivial 'Hello World!' application that builds 20 urls for each case. The benchmark is executed in isolated environment using CPython 2.7. Latest available versions (November 17, 2013):
  1. django 1.6
  2. flask 0.10.1
  3. pylons 1.0.1
  4. pyramid 1.5a2
  5. tornado 3.1.1
  6. wheezy.web 0.1.373
Let setup few prerequisites to be able run this in a clean debian testing installation.
apt-get install make python-dev python-virtualenv \
    mercurial unzip
The source code is hosted on bitbucket, let clone it into some directory and setup virtual environment (this will download all necessary package dependencies per framework listed above).
hg clone https://bitbucket.org/akorn/helloworld
cd helloworld/03-urls && make env
Once environment is ready we can run benchmarks:
env/bin/python benchmarks.py