ArcGIS Help 10.2 - Accessing licenses and extensions in Python

Whenever a tool is executed in a script, an ArcGIS license is required. Tools from ArcGIS extensions, such as the ArcGIS Spatial Analyst extension, require an additional license for that extension. If the necessary licenses are not available, a tool fails and returns error messages. For example, if you install with an ArcGIS for Desktop Basic license, and you attempt to execute a tool that requires a Standard or Advanced license, the tool will fail.

When using an ArcGIS for Desktop Basic or Standard license, a script should set the product to Basic or Standard. Likewise, when using an Engine or EngineGeoDB license, a script should set the product to Engine or EngineGeoDB. If a license is not explicitly set, the license will be initialized based on the highest available license level the first time an ArcPy tool, function, or class is accessed.

Every tool checks to ensure it has the appropriate license. If it doesn't have what's required, it fails. To guard against the situation of executing partially through and failing, you can perform a check at the top of your script and fail immediately.

Tip:

The setting of the product and extensions is only necessary within stand-alone scripts. If you are running tools from the Python window or using script tools, the product is already set from within the application, and the active extensions are based on the Extensions dialog box.

Desktop, Engine/Server licenses

Product modules are imported prior to the import of arcpy to define the desktop license used by a script. The CheckProduct function can be used to check the availability of desktop licenses, while the ProductInfo function reports what the current product license is.

Legacy:

The product level should be set by importing the appropriate product module (arcinfo, arceditor, arcview, arcserver, arcenginegeodb, or arcengine) prior to importing arcpy. The SetProduct function is a legacy function and cannot set the product once arcpy has been imported.

Extension licenses

Licenses for extensions can be retrieved from a license manager and returned once they are no longer needed. CheckExtension is used to see if a license is available to be checked out for a specific type of extension, while CheckOutExtension actually retrieves the license. Once the extension license has been retrieved by the script, extension tools can be executed. Once a script is done using tools from a particular extension, 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.

The following example executes some ArcGIS 3D Analyst tools and sets the desktop product license to ArcGIS for Desktop Basic, since an ArcGIS for Desktop Advanced license is not required to execute tools from an extension. The script will fail if the ArcGIS for Desktop Basic license is not explicitly set and no ArcGIS for Desktop Advanced license is available, since a desktop license is required to execute extension tools.

class LicenseError(Exception):
    pass

# Set desktop license used to ArcGIS for Desktop Basic
#
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", "westbrook_hill", 300)
    arcpy.Aspect_3d("WesternBrook", "westbrook_aspect")

except LicenseError:
    print "3D Analyst license is unavailable"  
except:
    print arcpy.GetMessages(2)
finally:
    # Check in the ArcGIS 3D Analyst extension
    #
    arcpy.CheckInExtension("3D")

In the above example, the ArcGIS 3D Analyst extension is checked in under a finally clause, ensuring that the extension is always checked back in, whether an exception has occurred or not.

A returned value of Failed, Unavailable, or NotLicensed indicates that the extension could not be successfully checked out.

Below are the extension names and their extension code names:

Extension	Extension Code
ArcGIS 3D Analyst extension	3D
ArcGIS Data Interoperability extension for Desktop	DataInteroperability
ArcGIS Data Reviewer for Desktop	Datareviewer
ArcGIS for Aviation: Airports	Airports
ArcGIS for Aviation: Charting	Aeronautical
ArcGIS for Maritime: Bathymetry	Bathymetry
ArcGIS for Maritime: Charting	Nautical
ArcGIS Geostatistical Analyst extension	GeoStats
ArcGIS Network Analyst extension	Network
ArcGIS Spatial Analyst extension	Spatial
ArcGIS Schematics extension	Schematics
ArcGIS Tracking Analyst extension	Tracking
ArcGIS Workflow Manager for Desktop	JTX
ArcScan	ArcScan
Business Analyst	Business
Esri Defense Mapping	Defense
Esri Production Mapping	Foundation
Esri Roads and Highways	Highways
StreetMap	StreetMap

Product code names

Product Codes
ArcView (equivalent to ArcGIS for Desktop Basic license)
ArcEditor (equivalent to ArcGIS for Desktop Standard license)
ArcInfo (equivalent to ArcGIS for Desktop Advanced license)
Engine
EngineGeoDB
ArcServer

Licensing functions

Function

Explanation

CheckExtension(extension)

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

Return Value	Meaning
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 the request.

CheckInExtension(extension)

Returns the license so other applications can use it.

Return Value	Meaning
NotInitialized	No desktop license has been set.
Failed	A system failure occurred during the request.
CheckedIn	The license has been returned successfully.

CheckOutExtension(extension)

Retrieves the license.

Return Value	Meaning
NotInitialized	No desktop license has been set.
Unavailable	The requested license is unavailable to be set.
CheckedOut	Successfully set the license.

CheckProduct(code)

Checks to see if the requested license is available.

Return Value	Meaning
AlreadyInitialized	License has already been set in the script.
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 the request.

ProductInfo()

Returns the current product license.

Return Value	Meaning
NotInitialized	No license has been set.
ArcInfo	An ArcGIS for Desktop Advanced license has been set.
ArcEditor	An ArcGIS for Desktop Standard license has been set.
ArcView	An ArcGIS for Desktop Basic license has been set.
ArcServer	An ArcGIS for Server license has been set.
EngineGeoDB	An EngineGeoDB license has been set.
Engine	An Engine license has been set.

SetProduct(code)

Defines the desktop license.

Return Value	Meaning
CheckedOut	Successfully set the license.
AlreadyInitialized	License has already been set in the script.
NotLicensed	The requested license is not valid.
Failed	A system failure occurred during the request.

3/3/2014