pythonui-automationpywinauto

Is it normal to get pywinauto.uia_defines.NoPatternInterfaceError

I wrote a program to automate the test of an app i did not create using pywinauto, but i got this error : pywinauto.uia_defines.NoPatternInterfaceError. It came when i tried this :

    app.connect(path=exe_path)
    main_dlg = app.top_window()
    main_dlg.wait('visible')
    truc = main_dlg.child_window(title="Users", control_type="Button")
    truc.click() # <- this is where the problem arised

Here is the code (so that you understand the context) :

from pywinauto.application import Application

*
* This is irrevelent
*

try:
    print("start")
    app = Application(backend="uia").start(exe_path)

    app.connect(path=exe_path)
    main_dlg = app.top_window()
    print("Is there a window : "+ str(main_dlg.exists()))
    main_dlg.wait('visible')


    # Here we can start to work

    # This let us see what the API see in the selected window
    main_dlg.print_control_identifiers()
    print(str(main_dlg.actions))

    truc = main_dlg.child_window(title="Users", control_type="Button")
    print(type(truc))
    print(str(truc))
    truc.print_control_identifiers()
    truc.click()

except Exception as e:
    print("PROBLEM")
    print("--------------------------------------------------------------")
    raise(e)
finally:
    print("Finally")

And here is what it print :

C:\Users\vboxuser\Documents\GST_tests\automation.py:3: SyntaxWarning: invalid escape sequence '\P'
  exe_path = "xxx"
start
Is there a window : True
Control Identifiers:

Dialog - 'xxx'    (L-8, T-8, R1928, B868)
['xxxDialog', 'Dialog', 'xxx']
child_window(title="xxx", control_type="Window")
   |
   | TitleBar - ''    (L16, T-5, R1920, B23)
   | ['TitleBar']
   |    |
   |    | Menu - 'Système'    (L0, T0, R22, B22)
   |    | ['SystèmeMenu', 'Système', 'Menu', 'Système0', 'Système1']
   |    | child_window(title="Système", auto_id="MenuBar", control_type="MenuBar")
   |    |    |
   |    |    | MenuItem - 'Système'    (L0, T0, R22, B22)
   |    |    | ['Système2', 'MenuItem', 'SystèmeMenuItem']
   |    |    | child_window(title="Système", control_type="MenuItem")
   |    |
   |    | Button - 'Réduire'    (L1779, T8, R1826, B22)
   |    | ['Button', 'Réduire', 'RéduireButton', 'Button0', 'Button1']
   |    | child_window(title="Réduire", control_type="Button")
   |    |
   |    | Button - 'Restaurer'    (L1826, T8, R1872, B22)
   |    | ['Button2', 'RestaurerButton', 'Restaurer']
   |    | child_window(title="Restaurer", control_type="Button")
   |    |
   |    | Button - 'Fermer'    (L1872, T8, R1928, B22)
   |    | ['Button3', 'FermerButton', 'Fermer']
   |    | child_window(title="Fermer", control_type="Button")
   |
   | Image - ''    (L16, T39, R408, B103)
   | ['Image']
   |
   | Button - 'Logon'    (L0, T120, R100, B170)
   | ['Logon', 'Button4', 'LogonButton', 'Logon0', 'Logon1']
   | child_window(title="Logon", control_type="Button")
   |    |
   |    | Static - 'Logon'    (L33, T137, R67, B152)
   |    | ['Logon2', 'Static', 'LogonStatic', 'Static0', 'Static1']
   |    | child_window(title="Logon", control_type="Text")
   |
   | Button - 'Hardware'    (L0, T170, R100, B220)
   | ['Hardware', 'Button5', 'HardwareButton', 'Hardware0', 'Hardware1']
   | child_window(title="Hardware", control_type="Button")
   |    |
   |    | Static - 'Hardware'    (L24, T187, R76, B202)
   |    | ['Hardware2', 'Static2', 'HardwareStatic']
   |    | child_window(title="Hardware", control_type="Text")
   |
   | Button - 'SNTP'    (L0, T220, R100, B270)
   | ['Button6', 'SNTP', 'SNTPButton', 'SNTP0', 'SNTP1']
   | child_window(title="SNTP", control_type="Button")
   |    |
   |    | Static - 'SNTP'    (L36, T237, R64, B252)
   |    | ['SNTPStatic', 'Static3', 'SNTP2']
   |    | child_window(title="SNTP", control_type="Text")
   |
   | Button - 'Network'    (L0, T270, R100, B320)
   | ['Button7', 'NetworkButton', 'Network', 'Network0', 'Network1']
   | child_window(title="Network", control_type="Button")
   |    |
   |    | Static - 'Network'    (L27, T287, R73, B302)
   |    | ['Static4', 'NetworkStatic', 'Network2']
   |    | child_window(title="Network", control_type="Text")
   |
   | Button - 'Users'    (L0, T320, R100, B370)
   | ['UsersButton', 'Button8', 'Users', 'Users0', 'Users1']
   | child_window(title="Users", control_type="Button")
   | *
   | *
   | *
   | * Not useful info that i cut
   | *
   | *
   | *
   | Button - 'Firmware'    (L0, T570, R100, B620)
   | ['Button13', 'Firmware', 'FirmwareButton', 'Firmware0', 'Firmware1']
   | child_window(title="Firmware", control_type="Button")
   |    |
   |    | Static - 'Firmware'    (L26, T587, R74, B602)
   |    | ['Static10', 'FirmwareStatic', 'Firmware2']
   |    | child_window(title="Firmware", control_type="Text")
<pywinauto.actionlogger._StandardLogger object at 0x000001C3EC87B290>
<class 'pywinauto.application.WindowSpecification'>
<pywinauto.application.WindowSpecification object at 0x000001C3EDAC3410>
Control Identifiers:

Button - 'Users'    (L0, T320, R100, B370)
['UsersButton', 'Button', 'Users', 'Users0', 'Users1']
child_window(title="Users", control_type="Button")
   |
   | Static - 'Users'    (L36, T337, R64, B352)
   | ['Static', 'Users2', 'UsersStatic']
   | child_window(title="Users", control_type="Text")
PROBLEM
--------------------------------------------------------------
Finally
Traceback (most recent call last):
  File "C:\Users\vboxuser\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.12_qbz5n2kfra8p0\LocalCache\local-packages\Python312\site-packages\pywinauto\uia_defines.py", line 234, in get_elem_interface
    iface = cur_ptrn.QueryInterface(cls_name)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\vboxuser\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.12_qbz5n2kfra8p0\LocalCache\local-packages\Python312\site-packages\comtypes\__init__.py", line 828, in QueryInterface
    self.__com_QueryInterface(byref(iid), byref(p))
ValueError: NULL COM pointer access

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Users\vboxuser\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.12_qbz5n2kfra8p0\LocalCache\local-packages\Python312\site-packages\pywinauto\controls\uia_controls.py", line 121, in click
    self.invoke()
  File "C:\Users\vboxuser\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.12_qbz5n2kfra8p0\LocalCache\local-packages\Python312\site-packages\pywinauto\controls\uiawrapper.py", line 513, in invoke
    self.iface_invoke.Invoke()
    ^^^^^^^^^^^^^^^^^
  File "C:\Users\vboxuser\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.12_qbz5n2kfra8p0\LocalCache\local-packages\Python312\site-packages\pywinauto\controls\uiawrapper.py", line 132, in __get__
    value = self.fget(obj)
            ^^^^^^^^^^^^^^
  File "C:\Users\vboxuser\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.12_qbz5n2kfra8p0\LocalCache\local-packages\Python312\site-packages\pywinauto\controls\uiawrapper.py", line 231, in iface_invoke
    return uia_defs.get_elem_interface(elem, "Invoke")
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\vboxuser\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.12_qbz5n2kfra8p0\LocalCache\local-packages\Python312\site-packages\pywinauto\uia_defines.py", line 236, in get_elem_interface
    raise NoPatternInterfaceError()
pywinauto.uia_defines.NoPatternInterfaceError

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Users\vboxuser\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.12_qbz5n2kfra8p0\LocalCache\local-packages\Python312\site-packages\pywinauto\uia_defines.py", line 234, in get_elem_interface
    iface = cur_ptrn.QueryInterface(cls_name)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\vboxuser\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.12_qbz5n2kfra8p0\LocalCache\local-packages\Python312\site-packages\comtypes\__init__.py", line 828, in QueryInterface
    self.__com_QueryInterface(byref(iid), byref(p))
ValueError: NULL COM pointer access

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Users\vboxuser\Documents\GST_tests\automation.py", line 31, in <module>
    raise(e)
  File "C:\Users\vboxuser\Documents\GST_tests\automation.py", line 26, in <module>
    truc.click()
  File "C:\Users\vboxuser\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.12_qbz5n2kfra8p0\LocalCache\local-packages\Python312\site-packages\pywinauto\controls\uia_controls.py", line 123, in click
    self.select()
  File "C:\Users\vboxuser\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.12_qbz5n2kfra8p0\LocalCache\local-packages\Python312\site-packages\pywinauto\controls\uiawrapper.py", line 605, in select
    self.iface_selection_item.Select()
    ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\vboxuser\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.12_qbz5n2kfra8p0\LocalCache\local-packages\Python312\site-packages\pywinauto\controls\uiawrapper.py", line 132, in __get__
    value = self.fget(obj)
            ^^^^^^^^^^^^^^
  File "C:\Users\vboxuser\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.12_qbz5n2kfra8p0\LocalCache\local-packages\Python312\site-packages\pywinauto\controls\uiawrapper.py", line 224, in iface_selection_item
    return uia_defs.get_elem_interface(elem, "SelectionItem")
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\vboxuser\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.12_qbz5n2kfra8p0\LocalCache\local-packages\Python312\site-packages\pywinauto\uia_defines.py", line 236, in get_elem_interface
    raise NoPatternInterfaceError()
pywinauto.uia_defines.NoPatternInterfaceError

From what i understand and what i saw in the documentation and the exemples, Users Button should be a clickable element. Did i do something wrong ?

Also, i found this post : github issue link that seems to have a similar issue. I also tried to use win32 backend instead of uia, but i got the same result as ripdog.

In the end it can be sumurised as : Is it my fault ? Is there an alternative way to click Button elements ?

Solution

  • Unfortunately not every application implements click handlers and other handlers properly on the application side. So it is kind of norm. :( But methods .click_input(), .type_keys(...) and similar should always work since they use native mouse and keyboard events. They only need active desktop: it means the PC is not locked or RDP window is not minimized and not disconnected. About RDP you can read Remote Execution Guide for proper settings and other workarounds