default - Open specific file type with Python script?

Question

How can I make a Python script to be a specific file type's (e.g., *.foo) default application? As in, when I double click the file in the Finder / Explorer I want the file to open in the Python script.

Is this possible to do in Win and/or OS X? The application is a PySide app if that matters.

Answer 1

Mac OS X

On Mac OS X you can use Automator to create an application that calls your python app and passes the input file path as a string argument. In the application workflow wizard, add action "Run Shell Script", select Pass input: as as arguments, and in the text box add:

python /path/to/my/app/myapp.py "$@"

The "$@" passes along whatever arguments were in the input (aka the selected file) as strings. As long as your script is set up to deal with the input (sys.argv) as a list of strings (the first one being the python app path), then it will work.

When you save that Automator workflow, it is treated by OS X like any other app, and you can set that app as the default for files of type "*.foo". To associate "*.foo" with that app, right click a .foo file, Get Info, Open with: Other..., choose the app you created in Automator, then click the Change All... button.

Windows

A similar but hopefully less-involved approach might work in Windows. You could probably create a batch file (.bat) with the following:

python C:pathomyappmyapp.py %*

The %* expands to all arguments.

As long as you can associate a file extension with that batch file, then you could do that, and that's your solution. However, I haven't tried this Windows solution, so take it with a grain of salt. The Mac solution, on the other hand, I have tested.