--- /usr/local/lib/python2.7/zipfile.py
+++ /tmp/zipfile.py
@@ -769,6 +769,8 @@
         self.mode = key = mode.replace('b', '')[0]
         self.pwd = None
         self._comment = ''
+        #!!! massimo.sala.71@gmail.com
+        self.offset = None

         # Check if we were passed a file-like object
         if isinstance(file, basestring):
@@ -843,6 +845,8 @@
         if endrec[_ECD_SIGNATURE] == stringEndArchive64:
             # If Zip64 extension structures are present, account for them
             concat -= (sizeEndCentDir64 + sizeEndCentDir64Locator)
+        #!!! massimo.sala.71@gmail.com
+        self.offset = concat

         if self.debug > 2:
             inferred = concat + offset_cd