Packaging a Python app?

["Steven M. Bellovin" <smb%cs.columbia.edu@localhost>]

I'm trying to package something that uses Python.  While I'm not sure what
version of Python it wants, our latest in 2.4 but 2.5 is now out, so I
should be flexible.  The program also needs paramiko, which we have as
security/py-paramiko.

I've tried including a dependency for security/py-paramiko, but it's saying

        WARNING: Skipping -paramiko-1.6:
        WARNING: No valid Python version
        ERROR: [depends.mk] A package matching ``py-paramiko>=1.6'' should
        ERROR:     be installed, but one cannot be found.  Perhaps there
        is a stale work directory for ../../security/py-paramiko?

I manually installed paramiko, which now shows up as py24-paramiko.  What
am I supposed to say as a dependency?  My Makefile now has

        DEPENDS+=       py-paramiko>=1.6:../../security/py-paramiko
        PYTHON_VERSIONS_ACCEPTED= 23 24
        .include "../../lang/python/application.mk"

(As a secondary matter, the programs start with 

        #!/usr/bin/env python

What is the proper invocation here?)

                --Steven M. Bellovin, http://www.cs.columbia.edu/~smb