niladri chakrabarty niladri chakrabarty - 3 months ago 66
Python Question

pywinauto.findwindows.WindowNotFoundError in pywinauto

I am new in pywinauto and have just started learning. I have installed pywinauto with pip in my local 32 bit Windows 7 OS.
So, I have this sample code to open an URL in chrome browser.

from pywinauto import application
app=application.Application()
app.start(r'C:\Program Files\Google\Chrome\Application\chrome.exe')
app.window_(title='New Tab')
app.window_().TypeKeys('{F6}')
app.window_().TypeKeys('{ESC}')
app.window_().TypeKeys('www.facebook.com')


On running it, it is throwing error:

Traceback (most recent call last):
File "pywinauto_nil.py", line 6, in <module>
app.window_().TypeKeys('{F6}')
File "C:\Python27\lib\site-packages\pywinauto\application.py", line 252, in
__getattr__
ctrls = _resolve_control(self.criteria)
File "C:\Python27\lib\site-packages\pywinauto\application.py", line 758, in _resolve_control
raise e.original_exception
pywinauto.findwindows.WindowNotFoundError


I have googled, but could not find any helpful solution.

Where am I going wrong?

Answer

The full answer would be long and complicated. Let's start from your small problem.

  1. Chrome spawns few more processes that is not connected with app object. Solution: use Application().connect(title='New tab') (or title_re or whatever possible for find_windows).

  2. The bigger problem is that Chrome controls cannot be detected and handled by pywinauto 0.5.4 because MS UI Automation support is on the way (70% done in UIA branch on GitHub, see the short intro). By the way, pywinauto/UIA can handle top-level windows in a process-agnostic way: Desktop(backend='uia').NewTab.type_keys('some_URL')

  3. One more detail about Chrome. It doesn't enable UIA support by default. To enable UIA accessibility it must run so: chrome.exe --force-renderer-accessibility. Though UIA mode is enabled by default in Firefox and Opera.

And finally pywinauto is not specifically designed for Web automation. Right now it might be combined with Selenium.

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