Tkinter filedialog.askdirectory() freezing when importing pywinauto

Hi,

I’ve logged this in the Python issue tracker already, but I’ve been told to follow up with you guys and see if it’s something that can be fixed on your end.

https://bugs.python.org/issue34029

Essentially, when pywinauto is imported, the tkinter.filedialog.askdirectory() function freezes the application and doesn’t open the askdirectory dialog.

From the bug:

Debugging a bit, the hang happens in Lib/tkinter/commondialog.py, line 43: s = w.tk.call(self.command, *w._options(self.options))

The value of self.command is ‘tk_chooseDirectory’, and w._options(self.options) just gives an empty tuple, so the actual call is: s = w.tk.call('tk_chooseDirectory', ())

This means that the hang is within w.tk.call().

[airelil]

Hi @rsteel1, finally we got the chance to look into this issue. I was able to reproduce the reported problem on my Win8.1 64-bit machine with 64-bit Python 3.6 using the code below

import pywinauto
import tkinter.filedialog
tkinter.filedialog.askdirectory()

Since this involves windows file dialogs I suspected that the origin of the problem is incompatible COM threading model. By default, pywinauto sets up the Multithreading COM model (MTA) on init if no other mode was defined prior to import of pywinauto or specified explicitly through sys.coinit_flags. My guess is askdirectory call uses “appartment threaded model” that is incompatible with MTA mode that was defined during pywinauto import. So to solve the problem we should specify the appropriate threading model explicitly as in the example below:

import sys
sys.coinit_flags = 2  # COINIT_APARTMENTTHREADED

import pywinauto
import tkinter.filedialog
tkinter.filedialog.askdirectory()

[ilykos]

This seems to be a pyglet issue. I am using Pyglet 1.5.15 on python 3.7. the askopenfilename() invokation causes the program to freeze.

My suboptimal solution to this was to askdirectory() before importing pyglet.