Layer properties

Résumé

The Describe function returns the following properties for Layers. Dataset Properties are also supported, as well as the properties of the data type, the layer references. For example, a layer that references a feature class will have access to FeatureClass Properties, while a layer that references a raster dataset will have access to Raster Dataset Properties.

• If the data element being described is a layer in a map or an in-memory layer, the dataType returned gives information about the data source of the layer being described. Some examples of this are "MosaicLayer", "FeatureLayer", and "GroupLayer".
• You can get information about the layer contained by a .lyrx or .lyr file by inspecting the Describe object returned by the layer property.

Propriétés

Propriété	Explication	Type de données
dataElement (Lecture seule)	The Describe object of the data source to which the layer refers.	Describe
endTimeField (Lecture seule)	The end time field of the layer (if the layer is time-aware).	String
featureClass (Lecture seule)	The Describe object of the feature class associated with the feature layer.	Describe
FIDSet (Lecture seule)	arcpy.Describe will return a semicolon-delimited string of selected feature IDs (record numbers). arcpy.da.Describe will return a list of selected feature IDs. If a selection has not been applied to the layer, FIDSet will return a None; if a selection was applied to the layer, but it returned no records, FIDSet will return an empty list.	Integer
fieldInfo (Lecture seule)	The FieldInfo object (property set) of the layer.	FieldInfo
layer (Lecture seule)	The Describe object of the layer within a .lyr file.	Describe
nameString (Lecture seule)	The name of the layer.	String
startTimeField (Lecture seule)	The start time field of the layer (if the layer is time-aware).	String
table (Lecture seule)	The Describe object of the table within a layer.	Describe
TimeZone (Lecture seule)	The time zone referred to by the start and end time fields (if time is specified for the layer).	String
whereClause (Lecture seule)	The layer's definition query where clause.	String

Exemple de code

Layer properties example (stand-alone script)

The following stand-alone script displays some layer properties from an in-memory feature layer.

import arcpy

# Create an in memory feature layer from a feature class.
#
arcpy.MakeFeatureLayer_management(
        "C:/data/chesapeake.gdb/bayshed",
        "mainlines_layer")

# Create a Describe object from the feature layer.
#
desc = arcpy.Describe("mainlines_layer")

# Print some properties of the feature layer, and its featureclass.
#
print("Name String:        " + desc.nameString)
print("Where Clause:       " + desc.whereClause)
print("Feature class type: " + desc.featureClass.featureType)

Layer properties example 2 (stand-alone script)

The following stand-alone script displays some layer properties from a .lyr file.

import arcpy


# Create a Describe object from a .lyr file.
#
desc = arcpy.Describe("c:/data/water_pipes.lyr")

# Print some properties of the feature layer
#
print("Name String:        " + desc.nameString)
print("Where Clause:       " + desc.whereClause)

# Find out if the layer represents a feature class
if desc.dataElement.dataType == "FeatureClass":
    print("Feature class:      " + desc.dataElement.catalogPath)
    print("Feature class Type: " + desc.featureClass.featureType)
else:
    print("Not a regular feature class")