topic Re: Python error: "Method RasterFieldName does not exist" in Geoprocessing Questions

Python error: "Method RasterFieldName does not exist"

KateParks — Thu, 29 Jul 2010 12:55:41 GMT

Hi,

I'm trying to write a python script that will print the name of a raster dataset to screen. I copied the example code from the Desktop Help and changed the raster object to match the path to my dataset:

import arcgisscripting
gp = arcgisscripting.create()

raster = "C:\data_all\AltLatGrids\ArcGISGrids\alb8__22"

# Create a describe object
#
desc = gp.Describe(raster)

# Print the RasterFieldName property
#
print desc.RasterFieldName

When I ran the script I received the error message "Method RasterFieldName does not exist". I am using ArcGIS 9.3 with an ArcInfo license, and Python 2.5.4.

Any help gratefully received!
Kate.

Re: Python error: "Method RasterFieldName does not exist"

GerryGabrisch — Thu, 29 Jul 2010 13:50:12 GMT

Python is backslash sensitive. Try:

raster = "C:\\data_all\\AltLatGrids\\ArcGISGrids\\alb8__22"

or

raster = r"C:\data_all\AltLatGrids\ArcGISGrids\alb8__22"

Re: Python error: "Method RasterFieldName does not exist"

KateParks — Thu, 29 Jul 2010 16:28:15 GMT

I tried both of those, but still get the same error.

Out of interest, what does the 'r' before your second suggestion do?

Re: Python error: "Method RasterFieldName does not exist"

GerryGabrisch — Thu, 29 Jul 2010 17:08:18 GMT

Ah,
RasterFieldName is not returning the name of the raster it returns the name of a field in a raster catalog. See

http://webhelp.esri.com/arcgisdesktop/9.3/index.cfm?id=1053&pid=980&topicname=Raster_Catalog_properties

Try this

import arcgisscripting
gp = arcgisscripting.create()
raster = r"C:\Temp\lidar"
# Create a describe object
desc = gp.Describe(raster)
# Print the name of the raster
print desc.Name

Backslashes are special characters, for example
print "Foo\nbar" would print
foo
bar
to the screen. The r sets the string to a raw string so r"Foo\nbar" would print
Foo\nbar

Re: Python error: "Method RasterFieldName does not exist"

KateParks — Fri, 30 Jul 2010 14:15:04 GMT

Thanks a lot for your help, that works now.