Object.IsNull - Converting an array to var would cause array rank reduction and is not permitted

1

Hello,

Getting nulls in my Room.FinishBoundary which i’ve posted about here.

I want to get the index of those nulls - but only when running the Graph on certain Revit levels do I get the following error from Object.IsNull:

Warning: Converting an array to var would cause array rank reduction and is not permitted

Revit 2019.2/Dynamo 1.3.4 (using this 1.3.4 because of the @Jeremy_Graham tutorial & Juggernaut Package)

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Any insight would be appreciated. 5077_50_Interior Elevations_Create by Room (Version 1.3.4).dyn (47.3 KB)

2

Hi Wayne,

The jagged list structure is causing the problem, the Object.IsNull node works well on consistently nested lists (in Dynamo 1.3) but not if the list structure varies like your example (although it works in Dynamo 2). You can use List.Map with IsNull but it will return for every element in the list, I’m not sure how useful this is for you.

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image952×552 29.3 KB

I’m assuming you want a single list with true for null values, and false for anything else (lists or values). This can be achieved with a single line of Python

OUT = [False if x is not None else True for x in IN[0]]

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image1107×738 35 KB

Hope this helps,
Thomas

1 Like
3

Evening Thomas,

Thanks for the reply :slight_smile: I’ll have a look at this in the morning when I’m back in the office and get back to you.