Topology Check Python AddIn (12/10/18)

05-02-2017 07:55 AM

Topology Check Python AddIn (12/10/18)

Hey everybody,

To echo what I wrote here: Topology AddIn Guinea Pig wanted 

On a monthly basis I create a bunch of topologys to make sure that my polygon layers don't overlap or have gaps (ESN). I also run a topology on my street layer to find street segments that aren't snapped. This process consists mostly of models.


Since I always try to help my Public safety brethren, I figured I compile my process in a Python AddIn, that "should be easy to use". You can check polygon layers for gaps and overlaps. You can also check line layers for unsnapped and overlapping features. This addon will automatically add the errors to your MXD and makes it easy to fix them.

Since the latest version is stable and ready for release, I figured I create a document in the python forum. When I update my AddIn, I will also update this document.

Latest Version 1.1: Dropbox -  (Added a check that will look for lines that are not broken at polygon borders)

If you would like to see the source code, you can download it here.

Please read the readme file after downloading the AddIn.

Let me know if you want anything added or if you find a bug!



New update is coming soon, with dangle tolerance box!

Let me know if there is anything else you would like added!

For those who are interested, background on the development of this AddIn by Tim can be found in Summer 2017 ArcUser article:

New Ways to Work | ArcUser 

Chris Donohue, GISP

Thanks for linking to this Chris.

New update coming soon that includes a button to make sure lines are broken at polygon borders. I use this in 911 to make sure my lines are broken at ESN boundaries/ city boundaries.

I guess by soon I meant almost a year later. Sorry for the delay!

Is there any interest in having this as an ArcGIS Pro Addin?

Good morning!  This tool has been very valuable to our GIS Department!  Our tax department is starting to use it for tax parcels.   Is there a way to adjust the tolerance for detecting polygon gaps and overlaps?  For some reason, the tool is not producing results for gaps and overlaps where they exist.  

Hey Maureen,

I am glad you are able to find use for my addon, this is always great to hear.

to my knowledge there is no tolerance value that can be adjusted. Do your tax collector use parcel fabric by any chance?


We do not use parcel fabric, but hope to convert in the near future.  The reason I'm using it for parcels is because we use the county parcel data for the base of Fire, EMS and Law polygon layers for NextGen 911.   I was hoping to use the Add-in to detect gaps and overlaps, though we're noticing it's not detecting some of them.  I was trying to avoid creating a geodatabase topology at this point, since geodb topology validation automatically fixes these errors rather than simply flag them.  Any advice appreciated!  

Would you mind sharing a sample of your data where you know there is a gap or overlap?

Do you use ArcGIS Pro? I am creating the same addin for ArcGIS Pro at the moment and maybe it works there.

On a side note, I am getting our data ready for next gen 911. Are you routing 911 calls spatialy already? 

Sure I created a small sample, but I can't figure out how to attach it here?  Should I just send it to you via email?  I am learning ArcPro here and there, but have not been able to dedicate very much time to it b/c of NextGen.  No, we are not routing calls spatially yet...still relying on the TelCo.  

If you follow me here I can DM you my work email address. Then you can send me the data.

OK I think I'm following you.

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