topic Re: Layer and calculate in Python Questions

Layer and calculate

TonyAlmeida — Thu, 09 Aug 2012 14:55:42 GMT

I would basically like to add an "Acres" field to the "selected" layer on the TOC regardless to the layers location on the TOC.
I am aware on how to do this with VBA but not with Python. I can't seem to find an arcy equivalent to pMxDoc.Selectedlayers to start off with.

Any help would be great!
Thanks.

Re: Layer and calculate

Anonymous User — Sat, 11 Dec 2021 07:14:50 GMT

This should work:

arcpy.env.workspace = r"<some/data/location>"

fc =  'Parcels.shp'
flyr = 'Parcels'
field = 'Acres'
expression = '!shape.area@acres!'

try:
    arcpy.MakeFeatureLayer_management(fc, flyr)
    arcpy.AddField_management(flyr, 'Acres', 'DOUBLE')
    arcpy.CalculateField_management(flyr, field, expression, 'PYTHON')

Caleb

Re: Layer and calculate

TonyAlmeida — Thu, 09 Aug 2012 15:35:47 GMT

This would only work if there was parcels.shp layer correct?
Is there a way to do this to any layer that is selected on the TOC?

Thank you for the reply i really appreciate it!

Re: Layer and calculate

Anonymous User — Thu, 09 Aug 2012 16:03:39 GMT

Tony,

I am sorry, I completely misunderstood what you meant. I'm sure that is possible, however I do not know how to do that. I'm sure someone will see this thread and can post how to do this. In the meantime you could look at the arcpy.mapping modules information. You could probably find the arcpy solution in there.

http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#/Introduction_to_arcpy_mapping/00s300000032000000/

Caleb