Network Attributes

Résumé

Provides information about network attributes that are defined for a given network dataset.

Discussion

For a given network attribute, edgeDirectionX, sourceNameX, evaluatorTypeX, and dataX are dynamic properties where X indicates a particular evaluator. The possible range of values for X depends on the evaluatorCount property. For example, if a network attribute named DriveTime has two evaluators as indicated by the evaluatorCount property, the DriveTime attribute will support edgeDirection0, sourceName0, evaluatorType0, data0, edgeDirection1, sourceName1, evaluatorType1, and data1 properties.

Similarly, for a given network attribute, parameterNameX, parameterTypeX, and parameterDefaultValueX are dynamic properties where X indicates a particular parameter. The possible range of values for X depends on the parameterCount property. For example, if a network attribute named DriveTime has two parameters as indicated by the parameterCount property, the DriveTime attribute will support parameterName0, parameterType0, parameterDefaultValue0, parameterName1, parameterType1,and parameterDefaultValue1 properties.

Propriétés

Propriété	Explication	Type de données
dataType (Lecture seule)	The network attribute data type. This property returns the following keywords: Boolean Integer Float Double	String
dataX (Lecture seule)	The value of the network attribute assigned to a network source using the evaluator. In case of a script evaluator, the entire expression is returned. The data type of the returned value depends on the data type and the evaluator type associated with the network attribute. dataX is a dynamic property. This property is not supported with SDC-based network datasets.	Variant
defaultEdgeData (Lecture seule)	The value for the network attribute that is associated by default with all the edge network sources in the network dataset. In case of a script evaluator, the entire expression is returned. The data type of the returned value depends on the data type and the default edge evaluator type associated with the network attribute.	Variant
defaultEdgeEvaluatorType (Lecture seule)	The default edge evaluator type used by the network dataset. This property returns the following keywords: Constant Script Function	String
defaultJunctionData (Lecture seule)	The value for the network attribute that is associated by default with all the junction network sources in the network dataset. In case of a script evaluator, the entire expression is returned. The data type of the returned value depends on the data type and the default junction evaluator type associated with the network attribute.	Variant
defaultJunctionEvaluatorType (Lecture seule)	The default junction evaluator type used by the network dataset. This property returns the following keywords: Constant Script Function	String
defaultTurnData (Lecture seule)	The value for the network attribute that is associated by default with all the turn network sources in the network dataset. In case of a script evaluator, the entire expression is returned. The property is available only if the network dataset supports turns that can be determined using the supportsTurns property. The data type of the returned value depends on the data type and the default turn evaluator type associated with the network attribute.	Variant
defaultTurnEvaluatorType (Lecture seule)	The network dataset default turn evaluator type. The property is available only if the network dataset supports turns that can be determined using the supportsTurns property. This property returns the following keywords: Constant Script Global Turn Delay Function	String
directions (Lecture seule)	A Network Directions Describe object that provides information about the network's directions configuration. If the network dataset does not support directions, this property will raise an exception.	Object
edgeDirectionX (Lecture seule)	The direction for the edge network sources along which the evaluator assigns the value for the network attribute. There is no direction associated with junction and turn network sources. edgeDirectionX is a dynamic property. This property returns the following keywords: AlongDigitizedDirection AgainstDigitizedDirection None	String
evaluatorCount (Lecture seule)	The total number of evaluators used to derive values from the given network source for this network attribute.	Integer
evaluatorTypeX (Lecture seule)	The type of evaluator. evaluatorTypeX is a dynamic property. This property returns the following keywords: Field Constant Script Function NetworkEdgeTraffic Public Transit	String
name (Lecture seule)	The name of the network attribute.	String
parameterCount (Lecture seule)	The total number of attribute parameters defined for the network attribute.	Integer
parameterDefaultValueX (Lecture seule)	The default value for the parameter. parameterDefaultValueX is a dynamic property that is supported only if the parameterCount value is greater than 0. The data type of the returned value depends on the data type of the attribute parameter.	Variant
parameterNameX (Lecture seule)	The name of the parameter. parameterNameX is a dynamic property that is supported only if the parameterCount value is greater than 0.	String
parameterTypeX (Lecture seule)	The data type for the parameter. parameterTypeX is a dynamic property that is supported only if the parameterCount value is greater than 0. This property returns the following keywords: String Short Integer Float Double Date Boolean Object String[] Short[] Integer[] Float[] Double[] Date[] Boolean[]	String
parameterUsageTypeX (Lecture seule)	The usage type for the parameter. This property returns the following keywords: General Restriction parameterUsageTypeX is a dynamic property that is supported only if the parameterCount value is greater than 0.	String
sourceNameX (Lecture seule)	The name of the network source for which the evaluator calculates the value of a given network attribute. sourceNameX is a dynamic property.	String
trafficSupportType (Lecture seule)	The type of traffic data currently configured for the network attribute. This property returns the following keywords: HISTORICAL HISTORICAL_AND_LIVE LIVE NONE	String
units (Lecture seule)	The units for the network attribute. Units of a cost attribute are either distance or time units, for example, centimeters, meters, miles, minutes, seconds. Descriptors, hierarchies, and restrictions have unknown units.	String
usageType (Lecture seule)	The network attribute usage type. This property returns the following keywords: Cost Restriction Descriptor Hierarchy	String
useByDefault (Lecture seule)	Indicates if the network attribute is used by default on a newly created network analysis layer. Only one cost attribute in the network dataset can be set to be used by default. Descriptor attributes cannot be used by default.	Boolean

Exemple de code

Network Attribute Properties Example

Display the network attribute information for a network dataset.

# Name: NDSAttributeProperties_ex01.py
# Description: Print the information about network attributes defined for the
#              network dataset

import arcpy

# Set workspace
arcpy.env.workspace = "C:/Data/Paris.gdb/Transportation"

# Create a Describe object from the network dataset
desc = arcpy.Describe("ParisMultimodal_ND")

# Get a list of network attributes
attributes = desc.attributes
#print information for each attribute
for attribute in attributes:
    print("----------------------------------\n")
    print("Name: ", attribute.name)
    print("Units: ", attribute.units)
    print("Usage Type: ", attribute.usageType)
    print("Data Type: ", attribute.dataType)
    print("Use By Default: ", str(attribute.useByDefault))
    #Information about  default evaluators
    print("Default edge evaluator type: ", attribute.defaultEdgeEvaluatorType)
    print("Default edge evaluator data: ", str(attribute.defaultEdgeData))
    print("Default junction evaluator type: ",attribute.defaultJunctionEvaluatorType)
    print("Default junction evaluator data: ",str(attribute.defaultJunctionData))
    #Turn specific information is supported only if network dataset supports
    #turns
    if desc.supportsTurns:
        print("Default turn evaluator type: ",attribute.defaultTurnEvaluatorType)
        print("Default turn evaluator data: ", str(attribute.defaultTurnData))

    #Describe all other evaluators
    count = attribute.evaluatorCount
    print("Evaluator count: ", count)
    for i in range(0, count):
        text = "Evaluator %d" % i
        print(text, " ---")
        edgeDir = getattr(attribute,"edgeDirection" + str(i))
        print("Edge direction: ", edgeDir)
        srcName = getattr(attribute,"sourceName" + str(i))
        print("Source Name: ", srcName)
        evaluatortype = getattr(attribute,"evaluatorType" + str(i))
        evaluatordata = getattr(attribute,"data" + str(i))
        print("Evaluator Type: ", evaluatortype)
        print("Evaluator Data: ", evaluatordata)

    #Describe attribute parameters
    print("Parameter Information........")
    paramcount = attribute.parameterCount
    if paramcount == 0:
        print("No Parameters defined.")
    else:
        print("Parameter Count: ", paramcount)
    for i in range (0, paramcount):
        paramName = getattr(attribute, "parameterName" + str(i))
        paramType = getattr(attribute, "parameterType" + str(i))
        paramDefaultValue = getattr(attribute, "parameterDefaultValue" + str(i))
        print("Parameter Name: ", paramName)
        print("Parameter Type: ", paramType)
        print("Parameter Default Value: ", paramDefaultValue)