Notes about IATI Python Code
Python2 vs Python3
All current IATI code is Python 3 or Node JS. However, some tools that have been flagged for review as a part of the Technical Stock Take remain in Python 2 (either on Github, or as deployed) while decisions on future tool-sets are pending.
A lot of our software has dependencies in common:
lxml, a fast XML toolkit that uses C libraries
Flask as the web framework
Jinja as the templating engine (including for use with Sphinx)
py.test - a no-boilerplate testing framework (although some code also uses nosetest and plain unit test)
We pin all our dependencies (including dependencies of dependencies) to an exact version in requirements.txt. This makes deployment more deterministic and reproducible. It also means that we can use requires.io to track out of date dependencies.
In order to install multiple version of the same dependency for different projects, we use virtualenv.
Currently most of our Python code is standalone scripts rather than python packages (ie. with a setup.py and installable with pip).