I want to select all the features in my Waterlines layer that share a line segment with other features in the same layer. I've done a complicated search cursor iteration in python that takes a couple hours, but I'd rather have something quicker.
I found this page that says you can do it simply with "select by location" which doesn't seem to work from the selection menu in arcmap, but kind of works in arcpy.
When I ran this:
arcpy.SelectLayerByLocation_management("waterlines_layer", "SHARE_A_LINE_SEGMENT_WITH", "", "", "NEW_SELECTION")
...it selected things that definitely didn't share a line segment with anything else. But it didn't select everything (which would have at least made some sense).