comtypes: how to provinde a list of string to a COM method

comtypes: how to provinde a list of string to a COM method - Printable Version

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comtypes: how to provinde a list of string to a COM method - zalanthas - Jun-26-2024

Working on Microsoft Windows [Version 10.0.19045.4412], Python 3.8.10 (I need to compile my script for Windows 7 as well...), comtypes 1.4.4

I am interacting with a Windows application through comtypes

import comtypes.client
import numpy as np
from comtypes.automation import VARIANT

comtypes.client.GetModule('path\to\application.exe')
from comtypes.gen import Application as App

comtypes.npsupport.enable()
MyApp = comtypes.client.CreateObject('CLSID', interface=App.IDualApplication)

and everything is working smooth: I found methods that asks for Variant (two-element array of double with array lower bound = 0 and array upper bound = 1) as an argument, defined as follows (inside its owner's class _methods_ list, of course)

COMMETHOD(
    [dispid(id), helpstring('Perform this action')],
    HRESULT,
    'ThisMethod',
    (['in'], VARIANT, 'dValues'),
)

I managed to deal with them with

MyApp.ThisMethod(VARIANT(np.array([x, y], dtype='float')))

Sweet!
Now, I have a method that asks for String array as an argument, defined as follows (inside its owner's class _methods_ list, of course)

COMMETHOD(
    [dispid(id), helpstring('Perform that action.')],
    HRESULT,
    'ThatMethod',
    (['in', 'optional'], VARIANT, 'strArrayItems'),
)

Here's how I tried to deal with it, with the results I got:

MyApp.ThatMethod(['x', 'y'])

Error:Traceback (most recent call last):
    MyApp.ThatMethod(['x', 'y'])
  File "\venv\lib\site-packages\comtypes\automation.py", line 568, in __ctypes_from_outparam__
    result = self.value
  File "\venv\lib\site-packages\comtypes\automation.py", line 520, in _get_value
    typ = _vartype_to_ctype[self.vt & ~VT_ARRAY]
KeyError: 9

MyApp.ThatMethod(VARIANT(np.array(['x', 'y'], dtype='str')))

Error:Traceback (most recent call last):
    MyApp.ThatMethod(['x', 'y'])
  File "\venv\lib\site-packages\comtypes\automation.py", line 215, in __init__
    self.value = args[0]
  File "\venv\lib\site-packages\comtypes\automation.py", line 344, in _set_value
    obj = _midlSAFEARRAY(VARIANT).create(value)
  File "\venv\lib\site-packages\comtypes\safearray.py", line 122, in create
    return cls.create_from_ndarray(value, extra)
  File "\venv\lib\site-packages\comtypes\safearray.py", line 165, in create_from_ndarray
    value = _ndarray_to_variant_array(value)
  File "\venv\lib\site-packages\comtypes\safearray.py", line 386, in _ndarray_to_variant_array
    if comtypes.npsupport.interop.VARIANT_dtype is None:
AttributeError: 'Interop' object has no attribute 'interop'

variant = VARIANT(VT_ARRAY | VT_BSTR)
variant.value = ['x', 'y']
MyApp.ThatMethod(variant)

Error:Traceback (most recent call last):
    MyApp.ThatMethod(variant)
  File "\venv\lib\site-packages\comtypes\automation.py", line 568, in __ctypes_from_outparam__
    result = self.value
  File "\venv\lib\site-packages\comtypes\automation.py", line 520, in _get_value
    typ = _vartype_to_ctype[self.vt & ~VT_ARRAY]
KeyError: 9

variant = VARIANT(VT_ARRAY | VT_BSTR)
variant.value = np.array(['x', 'y'], dtype='str')
MyApp.ThatMethod(variant)

Error:Traceback (most recent call last):
    variant.value = np.array(['x', 'y'], dtype='str')
  File "\venv\lib\site-packages\comtypes\automation.py", line 344, in _set_value
    obj = _midlSAFEARRAY(VARIANT).create(value)
  File "\venv\lib\site-packages\comtypes\safearray.py", line 122, in create
    return cls.create_from_ndarray(value, extra)
  File "\venv\lib\site-packages\comtypes\safearray.py", line 165, in create_from_ndarray
    value = _ndarray_to_variant_array(value)
  File "\venv\lib\site-packages\comtypes\safearray.py", line 386, in _ndarray_to_variant_array
    if comtypes.npsupport.interop.VARIANT_dtype is None:
AttributeError: 'Interop' object has no attribute 'interop'

How can I provide this COM method with a String array?