CheckExtension

Summary

Checks to see if a license is available to be checked out for a specific type of extension.

Once the extension license has been retrieved by the script, tools using that extension can be used. Once a script is finished with an extension's tools, the CheckInExtension function should be used to return the license to the License Manager so other applications can use it. All checked-out extension licenses and set product licenses are returned to the License Manager when a script completes.

Syntax

CheckExtension (extension_code)

Parameter	Explanation	Data Type
extension_code	Keyword for the extension product that is being checked. 3D —3D Analyst Schematics —ArcGIS Schematics ArcScan —ArcScan Business —Business Analyst DataInteroperability —Data Interoperability GeoStats —Geostatistical Analyst JTX — Workflow Manager Network —Network Analyst Aeronautical —Esri Aeronautical Solution Defense —Esri Defense Solution Foundation —Esri Production Mapping Datareviewer —ArcGIS Data Reviewer Nautical —Esri Nautical Solution Spatial —Spatial Analyst StreetMap —StreetMap Tracking —Tracking Licensing and extensions	String

Return Value

Data Type	Explanation
String	There are four possible returned values for CheckExtension: Available —The requested license is available to be set. Unavailable —The requested license is unavailable to be set. NotLicensed —The requested license is not valid. Failed —A system failure occurred during request.

Code Sample

CheckExtension example

Check for availability of 3D Analyst extension before checking it out.

class LicenseError(Exception):
    pass

import arcview
import arcpy
from arcpy import env

try:
    if arcpy.CheckExtension("3D") == "Available":
        arcpy.CheckOutExtension("3D")
    else:
        # raise a custom exception
        #
        raise LicenseError

    env.workspace = "D:/GrosMorne"
    arcpy.HillShade_3d("WesternBrook", "wbrook_hill", 300)
    arcpy.Aspect_3d("WesternBrook", "wbrook_aspect")
    arcpy.CheckInExtension("3D")

except LicenseError:
    print "3D Analyst license is unavailable"
except:
    print arcpy.GetMessages(2)