trying to gzip uncompress a StringIO

[bob at snee.com]

I'm using the code below to read the zipped, base64 encoded WMF file
saved in an XML file with "Save as XML" from MS Word. As the "At this
point" comment shows, I know that the base64 decoding is going fine,
but unzipping from the decodedVersion StringIO object isn't getting me
anything, because the len(fileContent) call is returning 0. Any
suggestions?

thanks,

Bob

###########################################

import sys, base64, gzip, StringIO

infile = sys.argv[1]
outfile = sys.argv[2]

# When unencoding base64 file, write to a string that acts like a file
decodedVersion = StringIO.StringIO()

base64.decode(open(infile, 'r'),decodedVersion)

# At this point, if we write out decodedVersion.getvalue() to a file,
# gzip -d makes a proper wmf file from it, so we know everything's OK
so far.

# following based on
# http://www.diveintopython.org/http_web_services/gzip_compression.html

fileObj = gzip.GzipFile(fileobj=decodedVersion);
fileContent = fileObj.read()
print len(fileContent)