topic Re: Check that features have been selected in Python Questions

Check that features have been selected

BrianPangtay — Thu, 24 May 2012 13:48:49 GMT

Can one check if any features have been selected in a Python script?

I want to check if any features have been selected prior to running the script. Otherwise, the script would try to process all the records in a feature class. Thus, if no features are selected, the script would tell the user to select some features and then exit the script.

Thanks for your help, Brian

Re: Check that features have been selected

BruceNielsen — Thu, 24 May 2012 14:00:56 GMT

One method I've used in the past is to compare the number of features in the input layer (arcpy.GetCount_management) with the number in the layer's source data (arcpy.describe::CatalogPath). If they are the same, nothing has been selected.

Re: Check that features have been selected

NobbirAhmed — Sat, 11 Dec 2021 19:28:51 GMT

Your selection is on a layer, right? if so then use FIDSet as follows:

dsc = arcpy.Describe("LayerName")

selection_set = dsc.FIDSet
if len(selection_set) == 0:
    # no feature is selected

Re: Check that features have been selected

JoseSanchez — Fri, 22 Jun 2012 18:36:22 GMT

How do you write this same code in 9.3.1?

Re: Check that features have been selected

NobbirAhmed — Fri, 22 Jun 2012 19:16:47 GMT

I think it is the same for 9.3 as well. Follow this link - you will see FIDSet property on a described object for a layer:

http://webhelp.esri.com/arcgisdesktop/9.3/index.cfm?TopicName=Layer_properties

Re: Check that features have been selected

deleted-user-8KkqhMYcTNGx — Mon, 04 Aug 2014 18:59:20 GMT

I found that this worked for me:

layers = arcpy.mapping.ListLayers(mxd)

for layer in layers:

desc = arcpy.Describe(layer)

selcount = desc.fidSet

if layer.name == "san_Wye":

print layer.name

if selcount <> "":

print "{0} features selected".format(len(desc.fidSet.split(';')))

if selcount == "":

print "no features selected"