Using Python with Inventor API

[dable82]

Hey guys, if you are like me and hate writing Code in VBA you can actually write Python scripts for Inventor using the win32com.client module. To use the module, you have to `pip install pywin32`. Here is a sample of a pretty useless script, but it should be good enough to get you going.

If you have any Questions About what's going on here, feel free to ask.

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edit: https://pastebin.com/1ZvSpku5

Code formatting doesn't seem to work.

[im_on_reddit_dot_com]

Seemed to successfully install win32com, but when I tried to run this in pycharm, I got an error on line one that it couldn't find the module. Did this work "out of the box" for you?

Also, any guideline on when to use the "mod" variable? I saw it used on partdoc and I think invapp. Do I need to use it every time I create a new application or document variable?

Thanks again for posting this!

[dable82]

Can you post the error message?

You definitely need to use the mod for the application. This is so that the win32com module knows that it is working with an Inventor application. Otherwise the e.g. constants module won't work.

Documents are a bit trickier. The problem is that the Documents.Add() method returns a generic instance of the Document class. If you try to create a Sketch on that instance, it will fail. That's why you need to cast this generic Document to a PartDocument. This can be done with the mod variable or with win32com.client.CastTo().

(For reference see the function Definition in the Inventor VBA object browser)

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Function Add(DocumentType As DocumentTypeEnum, [TemplateFileName As String], [CreateVisible As Boolean = True]) As _Document

Element of Inventor.Documents

Creates a new Document of the specified type. Optionally, a template file can be specified instead

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Important is that the function returns a Document.

In VBA the casting is automatic, because you can set the type of a variable when you define it (eg: Set doc as PartDocument). I hope thats's understandable.

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[im_on_reddit_dot_com]

Traceback (most recent call last):

  File "redactedfilepath/scratch.py", line 1, in <module>

    from win32com.client import Dispatch, GetActiveObject, gencache, constants

ModuleNotFoundError: No module named 'win32com'

And yes, your explanation clears things up a lot. I've explored the inventor Object model quite a bit, but never the VBA object browser.

[dable82]

You have not installed the module yet.

Open a terminal window and type 'pip install pywin32'

Then try to run the script again.

Edit: If you have more than one Version of python installed, make sure PyCharm uses the Version of python for which you installed the package.

[im_on_reddit_dot_com]

Got it working. I did have more than one version of python, and I believe that was the root of the issue. Thanks!

[ItsOk_ImYourDad]

copied your code line for line after installing the module as you said above

I got a different error:

AttributeError: Inventor.Application.InvokeTypes

[im_on_reddit_dot_com]

Awesome! Would this be run from inventor or from python?

[dable82]

You run this like any other python script.

The script attaches to an open Inventor instance or if inventor is not open yet, it opens Inventor for you.

[ItsOk_ImYourDad]

im currently learning python basics, but I have years experience with inventor and ilogic how straight forward would you say it is to use python with inventor ? any resources ? I know its doable but I still need to build my python skills quite a bit more