Is it possible to programmatically detect dependencies given a python project residing in SVN?
Absolutely! If you are working from a UNIX or Linux shell, a simple combination of grep and awk would work; basically, all you want to do is search for lines containing the "import" keyword.
However, if you are working from any environment, you could just write a small Python script to do the searching for you (don't forget that strings are treated as immutable sequences, so you can do something like if "import" in line: ....
The one sticky spot, would be associating those imported modules to their package name (the first one that comes to mind is the PIL module, in Ubuntu it's provided by the python-imaging package).
Python dependencies?