Supported OS X versions

Alfred 2 supports every version of OS X from 10.6 (Snow Leopard). Alfred-Workflow also supports the same versions, but there are a couple of things you have to watch out for because 10.6 has Python 2.6, while later versions have Python 2.7. As a result, if you want to maximise the compatibility of your workflow, you need to avoid using 2.7-only features in your code.

Here is the full list of new features in Python 2.7, but the most important things if you want your workflow to run on Snow Leopard are:

• argparse is not available in 2.6. Use getopt or include argparse in your workflow. Personally, I’m a big fan of docopt for parsing command-line arguments, but argparse is better for certain use cases.
• No dictionary views in 2.6.
• No set literals.
• No dictionary or set comprehensions.
• You must specify field numbers for str.format(), i.e. '{0}.{1}'.format(first, second) not just '{}.{}'.format(first, second).
• No Counter or OrderedDict in collections.

Python 2.6 is still included in later versions of OS X (up to and including Yosemite), so run your Python scripts with /usr/bin/python2.6 in addition to /usr/bin/python (2.7) to make sure they will run on Snow Leopard.