Python ArcGIS Geometry

Geometry

ArcGIS 10 Summary

Geometry objects define a spatial location and an associated geometric shape.

Discussion

In many geographic processing workflows, you may need to use coordinates and geometric information to run specific operations, but do not necessarily want to create a new (temporary) the process of using the element class, filling the element class with the cursor, and using the element class, and then deleting the temporary element class. You can use geometric objects to replace input and output to simplify geographic processing. You can use the geometry, multipoint, pointgeometry, polygon, or polyline class to create a geometric object from the beginning.

Syntax Geometry (geometry, inputs, {spatialreference}, {hasz}, {hasm })

Parameters	Description	Data Type
Geometry	The geometry type: Point, polygon, polyline, or multipoint.	String
Inputs	The coordinates used to create the object. The datatype can be either point or array objects.	Object
Spatialreference	The spatial reference of the new geometry. (Default value: None)	Spatialreference
Hasz	The Z state: true for geometry if z is enabled and false if it is not. (Default value: false)	Boolean
Hasm	The M state: true for geometry if M is enabled and false if it is not. (Default value: false)	Boolean

Attribute

Attribute	Description	Data Type
Area (Read-only)	The area of a polygon feature. Empty for all other feature types.	Double
Centroid (Read-only)	The true centroid if it is within or on the feature; otherwise, the label point is returned. Returns a point object.	Point
Extent (Read-only)	The extent of the geometry.	Extent
Firstpoint (Read-only)	The first coordinate point of the geometry.	Point
Hullrectangle (Read-only)	A space-delimited string of the coordinate pairs of the convex hull rectangle.	String
Ismultipart (Read-only)	True, if the number of parts for this geometry is more than one.	Boolean
Labelpoint (Read-only)	The point at which the label is located. The labelpoint is always located within or on a feature.	Point
Lastpoint (Read-only)	The last coordinate of the feature.	Point
Length (Read-only)	The length of the linear feature. Zero for point, multipoint feature types.	Double
Partcount (Read-only)	The number of geometry parts for the feature.	Integer
Pointcount (Read-only)	The total number of points for the feature.	Integer
Truecentroid (Read-only)	The center of gravity for a feature.	Point
Type (Read-only)	The geometry type: polygon, polyline, point, multipoint, multipatch, dimension, annotation.	String

Method Overview

Method	Description
Contains (second_geometry)	Indicates if the base geometry contains the comparison geometry. Contains is the opposite of. Only true relationships are shown in this procedure.
Crosses (second_geometry)	Indicates if the two geometries intersect in a geometry of a lesser shape type. Two polylines cross if they share only points in common, at least one of which is not an endpoint. A polyline and an polygon cross if they share a polyline or a point (for vertical line) in common on the interior of the polygon which is not equivalent to the entire polyline. Only true relationships are shown in this procedure.
Disjoint (second_geometry)	Indicates if the base and comparison geometries share no points in common. Two geometries Intersect if disjoint returns false. Only true relationships are shown in this procedure.
Equals (second_geometry)	Indicates if the base and comparison geometries are of the same shape type and define the same set of points in the plane. Only true relationships are shown in this procedure.
Getpart ({index })	Returns an array of point objects for a participant part of geometry or an array containing a number of arrays, one for each part.
Overlaps (second_geometry)	Indicates if the intersection of the two geometries has the same shape type as one of the input geometries and is not equivalent to either of the input geometries. Only true relationships are shown in this procedure.
Touches (second_geometry)	Indicates if the boundaries of the geometries intersect. Two geometries touch when the intersection of the geometries is not empty, but the intersection of their interiors is empty. for example, a point touches a polyline only if the point is coincident with one of the polyline end points. Only true relationships are shown in this procedure.
Within (second_geometry)	Indicates if the base geometry is within the comparison geometry. Within is the opposite operator of contains. Only true relationships are shown in this procedure.

Method Contains (second_geometry)

Parameters	Description	Data Type
Second_geometry	A second geometry.	Object

Return Value

Data Type	Description
Boolean	A return Boolean value of true indicates this geometry contains the second geometry.

Crosses (second_geometry)

Parameters	Description	Data Type
Second_geometry	A second geometry.	Object

Return Value

Data Type	Description
Boolean	A return Boolean value of true indicates the two geometries intersect in a geometry of a lesser shape type.

Disjoint (second_geometry)

Parameters	Description	Data Type
Second_geometry	A second geometry.	Object

Return Value

Data Type	Description
Boolean	A return Boolean value of true indicates that the two geometries share no points in common.

Equals (second_geometry)

Parameters	Description	Data Type
Second_geometry	A second geometry.	Object

Return Value

Data Type	Description
Boolean	A return Boolean value of true indicates that the two geometries are of the same shape type and define the same set of points in the plane.

Getpart ({index })

Parameters	Description	Data Type
Index	The index position of the geometry.	Integer

Return Value

Data Type	Description
Array	Getpart returns an array of point objects for a participant part of the geometry if an index is specified. if an index is not specified, an array containing an array of point objects for each geometry part is returned.

Overlaps (second_geometry)

Parameters	Description	Data Type
Second_geometry	A second geometry.	Object

Return Value

Data Type	Description
Boolean	A return Boolean value of true indicates the intersection of the two geometries has the same dimension as one of the input geometries.

Touches (second_geometry)

Parameters	Description	Data Type
Second_geometry	A second geometry.	Object

Return Value

Data Type	Description
Boolean	A return Boolean value of true indicates the boundaries of the geometries intersect.

Within (second_geometry)

Parameters	Description	Data Type
Second_geometry	A second geometry.	Object

Return Value

Data Type	Description
Boolean	A return Boolean value of true indicates this geometry is contained within the second geometry.

Code example geometry example

When you set the output parameter of a geoprocessing tool to a empty geometry object, the tool will return a list of geometry objects.

import arcpy# Create an empty Geometry object#g = arcpy.Geometry()# Run the CopyFeatures tool, setting the output to the geometry object.  GeometryList#  is returned as a list of geometry objects.#  geometryList = arcpy.CopyFeatures_management("c:/data/streets.shp", g)# Walk through each geometry, totalling the length#length = 0for geometry in geometryList:    length += geometry.lengthprint "Total length: %f" % length