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Network Analyst layer properties

Summary

The Describe function returns the properties described below for Network Analyst layers.

For a Network Analyst layer, the dataType property of the Describe function returns a value of "NALayer".

A Network Analyst layer contains information about the inputs and parameters used in the analysis of a network problem using the Network Analyst extension.

Properties

Property Explanation Data Type

network

(Read only)

The Network Dataset object.

This object can be used to get all the properties, such as catalogPath, of the underlying network dataset used by the analysis layer.

Object

nameString

(Read only)

The name of the Network Analyst layer.

String

solverName

(Read only)

The Network Analyst solver referenced by the layer. Each layer can reference only one solver. This property returns the following keywords:

  • Closest Facility Solver

  • Last Mile Delivery Solver

  • Location-Allocation Solver

  • OD Cost Matrix Solver

  • Route Solver

  • Service Area Solver

  • Vehicle Routing Problem Solver

  • Waste Collection Solver

String

impedance

(Read only)

The network cost attribute used as the impedance during the analysis.

String

accumulators

(Read only)

A semicolon-separated list of network cost attributes that are accumulated as part of the analysis.

String

restrictions

(Read only)

A semicolon-separated list of restriction attributes that are applied for the analysis.

String

ignoreInvalidLocations

(Read only)

Specifies whether invalid network locations in the Network Analyst classes are ignored by the solver.

A value of True indicates that the invalid locations are ignored by the solver. A value of False indicates that the invalid locations are not ignored by the solver.

Boolean

uTurns

(Read only)

Specifies how the U-turns at junctions, which could occur during network traversal between stops, are handled by the solver. This property returns the following keywords:

  • ALLOW_UTURNS

  • NO_UTURNS

  • ALLOW_DEAD_ENDS_ONLY

  • ALLOW_DEAD_ENDS_AND_INTERSECTIONS_ONLY

String

useHierarchy

(Read only)

Specifies whether the Network Analyst layer is using hierarchy. This property returns the following keywords:

  • USE_HIERARCHY

  • NO_HIERARCHY

String

hierarchyAttribute

(Read only)

The name of the hierarchy attribute.

String

hierarchyLevelCount

(Read only)

The number of hierarchy ranges used to define the hierarchy attribute. The maximum value is 3.

Integer

maxValueForHierarchyX

(Read only)

A given hierarchy attribute can have values that define the hierarchy ranges. The maximum values for each range can be obtained from the maxValueForHierarchyX property, where X indicates the hierarchy level. For example, the maximum value for the first hierarchy range (used to define the primary roads) can be obtained from the maxValueForHierarchy1 property.

Use the hierarchyLevelCount property to determine the possible number of maxValueForHierarchy properties for a given hierarchy attribute. For example, if the hierarchyLevelCount property returns 3, the Describe object will support the MaxValueForHierarchy1 and MaxValueForHierarchy2 properties.

Integer

locatorCount

(Read only)

The total number of classes that are searched to determine a network location.

Integer

locators

(Read only)

The Network Analyst Locator object. This object can be used to obtain the name, snap type, and search query information for the classes that are used for finding network locations.

Object

findClosest

(Read only)

Specifies how the network source features are searched when locating network analysis objects. This property returns the following keywords:

  • MATCH_TO_CLOSEST

  • PRIORITY

String

searchTolerance

(Read only)

A space-separated string indicating the search tolerance and the units used when finding the network locations.

String

excludeRestrictedElements

(Read only)

Specifies whether the network analysis objects can be located only on traversable portions of network sources This property returns the following keywords:

  • INCLUDE

  • EXCLUDE

String

solverProperties

(Read only)

The Network Analyst Solver object. This object can be used to determine the solver-specific properties in a Network Analyst layer.

Note:

Last mile delivery and waste collection analysis layers do not have this property.

Object

children

(Read only)

Returns a list of Describe objects that reference individual network analysis classes (such as stops and routes) as layers.

This property cannot be used with a network analysis layer stored on disk as a layer file.

List

parameterCount

(Read only)

The total number of attribute parameters defined for all the network attributes of the underlying network dataset used by the Network Analyst layer.

Integer

parameters

(Read only)

The Network Attribute Parameter object. This object can be used to determine the attribute parameters for the network analysis.

Object

SolverOverrides

(Read only)
Note:

This property is for internal use only.

String

Code sample

Network Analyst layer properties example

Display properties of a specified Network Analyst layer file.

# Name: NALayerProperties_ex01.py
# Description: Lists all the properties that can be derived by describing a
#              network analysis layer.

import arcpy

#Arguments..
#in_layer is the name of the Network Analysis layer file to be described.
in_layer = "C:/Data/Route.lyr"

#Get the description object using Describe.
desc = arcpy.Describe(in_layer)

arcpy.AddMessage(" ")
arcpy.AddMessage("== Description of network analysis layer " + in_layer + " ==")
arcpy.AddMessage(" ")

#Print general infomation.
justify = 35
nds = desc.network
solvername = desc.solverName
arcpy.AddMessage("---- General information:")
arcpy.AddMessage(" %*s: %s" % (justify, "Network" , nds.catalogPath))
arcpy.AddMessage(" %*s: %s" % (justify, "SolverName" , desc.solverName))
arcpy.AddMessage(" %*s: %s" % (justify, "Impedance" , desc.impedance))
arcpy.AddMessage(" %*s: %s" % (justify, "Accumulators" , desc.accumulators))
arcpy.AddMessage(" %*s: %s" % (justify, "Restrictions" , desc.restrictions))
arcpy.AddMessage(" %*s: %s" % (justify, "Ignore invalid locations?" ,
                str(desc.ignoreInvalidLocations)))
arcpy.AddMessage(" %*s: %s" % (justify, "UTurn policy" , desc.UTurns))
arcpy.AddMessage(" %*s: %s" % (justify, "Using hierarchy?" , desc.useHierarchy))
arcpy.AddMessage(" %*s: %s" % (justify, "Exclude Restricted Elements?" ,
                               desc.excludeRestrictedElements))
arcpy.AddMessage(" ")

#A note about the dynamic properties (indicated by X in the help system)
#In order to access the dynamic properties use Python's built in getattr()
#function. In order to find out if a dynamic property is supported by the
#describe object, use Python's built in hasattr() function.

# Print attribute parameter information
arcpy.AddMessage(" ---- Attribute Parameter information ----")
count = desc.parameterCount
if count == 0:
    arcpy.AddMessage(" ---- No Attribute Parameters defined ----")
else:
    parameters = desc.parameters
    for i in range(0, count):
        attributeName = getattr(parameters,"attributeName" + str(i))
        parameterName = getattr(parameters, "parameterName" + str(i))
        parameterValue = getattr(parameters, "parameterValue" + str(i))
        arcpy.AddMessage(" %*s: %s: %s" % (justify, attributeName,
                                           parameterName, parameterValue))

# Print hierarchy information
if desc.useHierarchy.lower() == "use_hierarchy":
    arcpy.AddMessage(" ---- Hierarchy information ----")
    arcpy.AddMessage(" %*s: %s" % (justify, "Hierarchy Attribute Name",
                                   desc.hierarchyAttribute))
    count = desc.hierarchyLevelCount
    arcpy.AddMessage(" %*s: %d" % (justify, "Hierarchy Level Count" , count))

    for i in range(0, count ):
        levelRange = ""
        if i == 0:
            levelUB = getattr(desc,"maxValueForHierarchy" + str(i+1))
            levelRange = "up to %s" % levelUB
        elif i == (count - 1):
            prevLevelUB = getattr(desc, "maxValueForHierarchy" + str(i))
            levelRange = "%s and higher" % (prevLevelUB + 1)
        else:
            prevLevelUB =  getattr(desc, "maxValueForHierarchy" + str(i))
            levelUB = getattr(desc,"maxValueForHierarchy" + str(i + 1))
            levelRange = "%s - %s" % ((prevLevelUB + 1), levelUB)

        arcpy.AddMessage(" %*s %d range: %s" % (justify, "level", (i + 1),
                                                levelRange))

    arcpy.AddMessage(" ")

# Print locator information.
arcpy.AddMessage("---- Locator information:")
count = desc.locatorCount
arcpy.AddMessage(" %*s: %d" % (justify, "Count" , count))
arcpy.AddMessage(" %*s: %s" % (justify, "Find Closest?" , desc.findClosest))
arcpy.AddMessage(" %*s: %s" % (justify, "Search Tolerance",
                               desc.searchTolerance))
arcpy.AddMessage(" %*s: %s" % (justify, "Exclude Restricted Elements",
                               desc.excludeRestrictedElements))
locators = desc.locators
for i in range(0, count):
    sourceName = getattr(locators, "source" + str(i))
    sourceType = getattr(locators, "snapType" + str(i))
    searchQuery = getattr(locators, "searchQuery" + str(i))
    arcpy.AddMessage(" %*s: %s" %(justify, sourceName, sourceType))
    arcpy.AddMessage(" %*s: %s" %(justify, sourceName, searchQuery))