Sort a polygon feature class spatially using Python

I was manually adjusting a custom grid for a map series this morning, a task which I have not had to do for several years now, when the time came to export the maps. By this point, my grid numbers were completely messed up because of all the shifting and reshaping I had to do.

It would make sense to number the grid from left to right, top to bottom. However, the ability to spatially sort a feature class in ArcGIS is hidden behind an Advanced Licence in the Sort tool.

License: For the Field(s) parameter, sorting by the Shape field or by multiple fields is only available with an Desktop Advanced license. Sorting by any single attribute field (excluding Shape) is available at all license levels.

I had this prickly feeling in the back of my head that I had found a workaround for this before. I went searching through the blog (since I have posted about things twice because I forgot about the first post), but I didn’t find it.

Undeterred, I searched through my gists (unrelated note – why does using the “user:<username> <search term> ” trick in the GitHub search bar now flag as spam?!) and I found it!

Link for mobile users is here.

I’m pretty sure there is a much better way to do this, but I need this so rarely that I don’t see the need to rewrite it. It also would work much better as a function. It takes a polygon feature class and sorts the selected features from left to right, top to bottom.

Description of this hastily drawn, blurry PowerPoint graphic: Chaotic, unsorted grid on the left. Slightly less chaotic, sorted grid on the right.

Export selected data driven pages only

A common task I perform with the asset management data is to create mapbooks per service (Water, Electricity etc) per main town/area/grid. I normally do this at the start of the project, to display the data we currently have. The asset guys then take the maps to the client, who will mark up amendments and additions.

While I cringe at having to create hard copies of anything, it’s the quickest way to get the information out of the client. It’s also relatively easy for me to create the mapbooks – I just have to open my service templates, save a new copy, set the data sources and CS to my current area, and export. I could automate this part of the process also, but often I need to visually confirm that the “current” data I am using is actually “current”.

When I set up the data driven pages for an area, I switch on all the asset data layers I have, and see which towns they are grouped into. I create best-fit rectangles around them, either by eyeballing it and drawing it in graphics, or using the Strip Map Index Features tool. Often, some areas won’t have Electricity data, or the Water Supply data only covers 3 out of the 5 grid blocks which covers the town.

Before, I would manually check this, and create separate index layers for each service, which would be used for that service’s data driven pages. This was a terrible way to do things, but doing it that way is what made me determined to find a better way. To Python!

This script takes a folder containing the various service MXDs, which have been set up so that the operational data is in a group layer called Data. Each of these layers is intersected with the data driven pages index layer, to determine which DDP polys contain the operational data. In Line 35, I’ve specified the selection_type as ADD_TO_SELECTION, so as not to lose the previously selected pages.

In Line 39, instead of making the traditional call to arcpy.mapping.ExportToPDF, I used dataDrivenPages.exportToPDF instead. The funny thing about the ArcGIS documentation is that I can look at the same pages so many times, and still discover new things.

What I like about this method is that it allows a SELECTED page range to be exported. This allows me to only have one index layer for an area 🙂 At the end of the script, I put some code in to convert the entire map to a KMZ file. That portion currently does not work, because the imagery basemap needs to be removed from the mxd before it can be converted. This should be as simple as calling RemoveLayer on the basemap, but I always have fantastic problems working with the layer movement methods (insert, add, move etc).

Edit: I just saw that I actually posted this script in July as well, when I wrote it initially. I was just so excited.