Python's zipfile module doesn't recognize a zipfile

Question

I downloaded some zip files but I cant use zipfile module to unzip them.

import zipfile
z = zipfile.ZipFile("00951999AP.wtl","r")
BadZipfile: File is not a zip file

File says it is a multifile-zip, but I know it isn't because I can unzip it on b1freearchiver

file 00951999AP.wtl
00951999AP.wtl: Zip multi-volume archive data, at least PKZIP v2.50 to extract

What should I do?

In [11]: zipfile.ZipFile("00951999AP.wtl")
---------------------------------------------------------------------------
BadZipfile                                Traceback (most recent call last)
<ipython-input-11-05921d85d623> in <module>()
----> 1 zipfile.ZipFile("00951999AP.wtl")

/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/zipfile.pyc in __init__(self, file, mode, compression, allowZip64)
    710 
    711         if key == 'r':
--> 712             self._GetContents()
    713         elif key == 'w':
    714             # set the modified flag so central directory gets written

/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/zipfile.pyc in _GetContents(self)
    744         is bad."""
    745         try:
--> 746             self._RealGetContents()
    747         except BadZipfile:
    748             if not self._filePassed:

/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/zipfile.pyc in _RealGetContents(self)
    759             raise BadZipfile("File is not a zip file")
    760         if not endrec:
--> 761             raise BadZipfile, "File is not a zip file"
    762         if self.debug > 1:
    763             print endrec

BadZipfile: File is not a zip file