BadZipfile "file is not a zip file"

[MRAB]

webcomm wrote:
> On Jan 8, 8:39 pm, "James Mills" <prolo... at shortcircuit.net.au> wrote:
>> Send us a sample of this file in question...
> 
> Here's a sample with some dummy data from the web service:
> http://webcomm.webfactional.com/htdocs/data.zip
> 
> That's the zip created in this line of my code...
> f = open('data.zip', 'wb')
> 
> If I open the file it contains as unicode in my text editor (EditPlus)
> on Windows XP, there is ostensibly nothing wrong with it.  It looks
> like valid XML.  But if I return it to my browser with python+django,
> there are bad characters every other character
> 
> If I unzip it like this...
> popen("unzip data.zip")
> ...then the bad characters are 'FFFD' characters as described and
> pictured here...
> http://groups.google.com/group/comp.lang.python/browse_thread/thread/...
> 
> If I unzip it like this...
> getzip('data.zip', ignoreable=30000)
> ...using Scott's function at...
> http://groups.google.com/group/comp.lang.python/msg/c2008e48368c6543
> ...then the bad characters are \x00 characters.
> 
I can unzip it in Windows XP. The file within it (called "data") is XML 
encoded as UTF-16LE (2 bytes per character, low byte first), but without 
the initial byte order mark. Python's zipfile module says "BadZipfile: 
File is not a zip file".