get_excel_hwnds throws an error in case no Excel application is running

[sdementen]

While running nosetests, I get errors if no Excel is open when starting the tests.

Some debugging led me to an issue in the get_excel_hwnds function. The function win32gui.FindWindowEx is used in a if construct but in fact the function throws a pywintypes.error when it fails. I think the function should instead be

def get_excel_hwnds():
    hwnds = []
    win32gui.EnumWindows(lambda hwnd, result_list: result_list.append(hwnd), hwnds)

    excel_hwnds = []
    for hwnd in hwnds:
        try:
            win32gui.FindWindowEx(hwnd, 0, 'XLDESK', None)
        except pywintypes.error:
            pass
        else:
            excel_hwnds.append(hwnd)

    return excel_hwnds

[fzumstein]

I can't duplicate that. Can you check in the Task Manager if you have some Zombie Excel processes running when you get this?

[fzumstein]

Also, what's the exact error message you're seeing?

[sdementen]

When I have an excel process (normal but also just zombie), I do not have
the error. It is once I have no more excel process (nor normal nor zombie)
that I get the error

On Tuesday, October 20, 2015, Felix Zumstein notifications@github.com
wrote:

I can't duplicate that. Can you check if you check in the Task Manager if
have some Zombie Excel processes running when you get this?

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#269 (comment)
.

[fzumstein]

What versions of Excel/Python/Windows are you using?

[sdementen]

Excel 2007/2.7/xp

On Tuesday, October 20, 2015, Felix Zumstein notifications@github.com
wrote:

What versions of Excel/Python/Windows are you using?

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#269 (comment)
.

[fzumstein]

ooh xp is a tough one ,-)

[sdementen]

Error code = 2 "The system cannot find the file specified."

On Tuesday, October 20, 2015, Felix Zumstein notifications@github.com
wrote:

Also, what's the exact error message you're seeing?

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#269 (comment)
.

[fzumstein]

When you try to reproduce it manually, does it happen when you run Workbook() or only when you run Workbook(r'some\path\file.xlsx')?

[sdementen]

I did not try anything else than running nosetests...
in the tests it tries to open the test_workbook_1.xlsx file in the test
folder and it fails when it goes through the workbook init
-> is_file_open -> get_xl_apps -> get_excel_hwns -> error

On Tuesday, October 20, 2015, Felix Zumstein notifications@github.com
wrote:

When you try to reproduce it manually, does it happen when you run
Workbook() or only when you run Workbook(r'some\path\file.xlsx')?

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#269 (comment)
.

[fzumstein]

sure but if the tests are responsible for making it fail then I'd rather fix the tests than the library itself.

[sdementen]

except if the test uses xlwings in a non "approved/orthodox" way, I would rather think the test has found a bug that need to be fixed ;-)

The traceback is the following

======================================================================
ERROR: xlwings.tests.test_xlwings.TestWorkbook.test_workbook_name
----------------------------------------------------------------------
Traceback (most recent call last):
  File "...\lib\site-packages\nose\case.py", line 381, in setUp
    try_run(self.inst, ('setup', 'setUp'))
  File "...\lib\site-packages\nose\util.py", line 471, in try_run
    return func()
  File "...\xlwings\tests\test_xlwings.py", line 152, in setUp
    self.wb = Workbook(xl_file1, app_visible=False, app_target=APP_TARGET)
  File "...\xlwings\main.py", line 153, in __init__
    if not os.path.isfile(fullname) or xlplatform.is_file_open(self.fullname):
  File "...\xlwings\_xlwindows.py", line 118, in is_file_open
    for xl_app in get_xl_apps():
  File "...\xlwings\_xlwindows.py", line 98, in get_xl_apps
    hwnds = get_excel_hwnds()
  File "...\xlwings\_xlwindows.py", line 90, in get_excel_hwnds
    if  win32gui.FindWindowEx(hwnd, 0, 'XLDESK', None):
error: (2, 'FindWindowEx', 'The system cannot find the file specified.')

And I have printed the hwnd and the GetWindowText(hwnd)

-------------------- >> begin captured stdout << ---------------------
65992 TF_FloatingLangBar_WndTitle

--------------------- >> end captured stdout << ----------------------

When running just the script

import win32gui
win32gui.FindWindowEx(65992, 0, 'XLDESK', None)

I get the same error

Traceback (most recent call last):
  File ".../xlwings/tests/test.py", line 3, in <module>
    win32gui.FindWindowEx(65992, 0, 'XLDESK', None)
pywintypes.error: (2, 'FindWindowEx', 'The system cannot find the file specified.')

So I wonder if the proper way to use FindWindowEx is both to check the output and to catch exceptions ... but I must say I can't find a lot of doc on this on google.

[fzumstein]

fixed by d2d3f95