win32com won't quit select sites in Internet Explorer

Question

Trying to get IE to quit inside of a thread. If I navigate to google.com or facebook.com it has no problem, the ie.Quit() works just fine. However, when I navigate to our company sharepoint site I get:

Error in IEThread:  (-2147352567, 'Exception occurred.', (0, None, None, None, 0, -2147467259), None
Exception in thread Thread-1:
Traceback (most recent call last):
  File "C:\python27\lib\threading.py", line 808, in __bootstrap_inner
    self.run()
  File "PepTalk.pyw", line 404, in run
    ie.Quit()
  File "C:\python27\lib\site-packages\win32com\client\dynamic.py", line 522, in __getattr__
    raise AttributeError("%s.%s" % (self._username_, attr))
AttributeError: InternetExplorer.Application.Quit

It doesn't make any sense because the AttributeError is for something that I can make the same script do with a different address. I'm running IE in it's own thread, here is my code:

class IEThread(Thread):
    def __init__(self):
        Thread.__init__(self)
        self.queue = Queue()

    def run(self):
        ie = None
        pythoncom.CoInitialize()
        try:
            ie = Dispatch('InternetExplorer.Application')
            ie.Visible = 1
            url = self.queue.get()
            print 'Visiting...', url
            ie.Navigate(url)
            while ie.Busy:
                time.sleep(0.1)
        except Exception, e:
            print "Error in IEThread: ", e

        if ie is not None:
            ie.Quit()

ieThread = IEThread()
ieThread.start()
url = 'https://company.sharepoint.com/company/Shared Documents/Weekly Pep Talk/2013/'
ieThread.queue.put(url)

Any ideas why this would be happening?

Answer 1

The most likely explanation is that you're navigating to an Intranet Zone site, which causes IE to perform an in-place process switch (replacing the Low Integrity Internet Zone tab with a Medium Integrity Intranet Zone tab). Thus the handle you're holding no longer points to the active tab process.

There's some discussion of this issue in my IEInternals post here: http://blogs.msdn.com/b/ieinternals/archive/2011/08/03/internet-explorer-automation-protected-mode-lcie-default-integrity-level-medium.aspx

Answer 2

It is actually possible to solve this in Python by calling the Dispatch with the CLSID that is associated with the Medium Integrity Intranet Zone.

import win32com.client
from time import sleep

ie = win32com.client.Dispatch('{D5E8041D-920F-45e9-B8FB-B1DEB82C6E5E}')
ie.Navigate(intranet_url)

while ie.Busy:
    sleep(0.1)

ie.Quit()  

Works !