Can't get compression in Python zip script.

[deejaay at swbell.net]

Hello,
I following an example on how to zip files from the www.devshed.com 
site.
I can create a zip package, however I am not getting any compression.
120M file stays 120M within the zip package.
I need to know how to set or activate the compression values.
here is the code I'm using:

>import zipfile
>zip = zipfile.ZipFile('<path/zipfilename.zip>', 'w')
>zip.write('<path/filename.txt>')
>zip.close()

Any help would be gratly appreciated

deej