$ python
Python 2.7.2 (default, Oct 11 2012, 20:14:37)
[GCC 4.2.1 Compatible Apple Clang 4.0 (tags/Apple/clang-418.0.60)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import subprocess
>>> subprocess.call(['zip', 'example.zip', 'example/*'])
    zip warning: name not matched: example/*

zip error: Nothing to do! (example.zip)
12
>>> quit()
$ zip example.zip example/*
  adding: example/file.gz (deflated 0%)

import glob
import subprocess

subprocess.call(['zip', 'example.zip'] + glob.glob('example/*'))

directory = 'example'
subprocess.call(['zip', '-r', 'example.zip', directory])