Retrieves the license from the License Manager.
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.
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.
Keyword for the extension product that is being checked.
There are three possible returned values for CheckOutExtension:
Check out 3D extension for use by tools.
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)