How to check if a specific Django App is installed using Ant?

Question

I would like to create an ant conditional target that checks if a django app is installed such as south. If It is installed, nothing to do but If not, run pip install south.

How could I do it using Ant?

Answer 1

Why not just have ant run pip with target version specified, i.e.

pip install south==0.7.4

If package already installed, pip will ignore it:

Requirement already satisfied (use --upgrade to upgrade): south==0.7.4 in ...