Finding closed polylines

Question

Does anyone know how to find closed polylines using only geoprocessing tools (without using Data Reviewer or ArcObjects)?  It seems like I should be able to do this in Python without much hassle, but I can't find a way.  Thanks!

deleted-user-AyQ-Iok8btBJ · Answer

How would I implement this into a field calculator expression? I'm a beginner with python but I could use some help. Basically I'm trying to implement this but rather than print the OID I want to populate a 1 for closed polylines and 0 for open. Thanks.

DanLee · Answer

If you have ArcInfo license, you can try the two steps:

1. Run Feature To Polygon tool to get polygons from closed lines.
2. Run Select Layer By Location to select polylines by the polygons, with the INTERSECT relationship option (or other suitable options). The resulting selection should contain closed polylines.

RichardPascoe · Answer

Jake and Mark - This is a great idea!  A polyline can be closed at two points that aren't the first and last, but this gives me a good starting point.  I will post the code once I am finished.  I imagine I will make a set of the coordinates for each feature and see if there are any that appear twice.

Hardolph - This will be a good alternative if the above doesn't work well.  Since I am automating, I want to avoid creating additional features, particularly for large datasets.  However, it is a simple process.  I would just need to create the polygons, join them back to the original features, select by attribute, and delete features.

Many thanks to all of you!