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Layer properties

Summary

The Describe function returns the following properties for Layers. The Dataset property group is 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 the Feature Class property group, while a layer that references a raster dataset will have access to the Raster Dataset property group.

  • 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.

Properties

Property Explanation Data Type

dataElement

(Read only)

The Describe object of the data source to which the layer refers.

Describe

endTimeField

(Read only)

The end time field of the layer (if the layer is time-aware).

String

featureClass

(Read only)

The Describe object of the feature class associated with the feature layer.

Describe

FIDSet

(Read only)

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

(Read only)

The FieldInfo object (property set) of the layer.

FieldInfo

layer

(Read only)

The Describe object of the layer within a .lyr file.

Describe

nameString

(Read only)

The name of the layer.

String

startTimeField

(Read only)

The start time field of the layer (if the layer is time-aware).

String

table

(Read only)

The Describe object of the table within a layer.

Describe

TimeZone

(Read only)

The time zone referred to by the start and end time fields (if time is specified for the layer).

String

whereClause

(Read only)

The layer's definition query where clause.

String

Code sample

Layer properties example 1

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.management.MakeFeatureLayer(
        "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

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")