Geometry (arcpy)
Summary
Geometry objects define a spatial location and an associated geometric shape.
Discussion
In many geoprocessing workflows, you may need to run a specific operation using coordinate and geometry information but don't necessarily want to go through the process of creating a new (temporary) feature class, populating the feature class with cursors, using the feature class, then deleting the temporary feature class. Geometry objects can be used instead for both input and output to make geoprocessing simpler. Geometry objects can be created from scratch using Geometry, Multipoint, PointGeometry, Polygon, or Polyline classes.
Syntax
Parameter  Explanation  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 
spatial_reference 
The spatial reference of the new geometry. (The default value is None)  SpatialReference 
has_z 
The Z state: True for geometry if Z is enabled and False if it is not. (The default value is False)  Boolean 
has_m 
The M state: True for geometry if M is enabled and False if it is not. (The default value is False)  Boolean 
Properties
Property  Explanation  Data Type 
JSON (Read Only)  Returns a JSON representation of the geometry as a string. Tip: The returned string can be converted to a dictionary using Python's json.loads function.  String 
WKB (Read Only)  Returns the wellknown binary (WKB) representation for OGC geometry. It provides a portable representation of a geometry value as a contiguous stream of bytes.  Bytearray 
WKT (Read Only)  Returns the wellknown text (WKT) representation for OGC geometry. It provides a portable representation of a geometry value as a text string.  String 
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 and Write) 
The extent of the geometry.  Extent 
firstPoint (Read Only) 
The first coordinate point of the geometry.  Point 
hullRectangle (Read Only) 
A spacedelimited 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 and multipoint feature types.  Double 
length3D (Read and Write)  The 3D length of the linear feature. Zero for point and 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 
spatialReference (Read Only)  The spatial reference of the geometry.  SpatialReference 
trueCentroid (Read Only) 
The center of gravity for a feature.  Point 
type (Read Only) 
The geometry type: polygon, polyline, point, multipoint, multipatch, dimension, or annotation.  String 
Method Overview
Method  Explanation 
boundary () 
Constructs the boundary of the geometry. 
buffer (distance) 
Constructs a polygon at a specified distance from the geometry. 
clip (envelope) 
Constructs the intersection of the geometry and the specified extent. 
contains (second_geometry) 
Indicates if the base geometry contains the comparison geometry. contains is the opposite of within. Only True relationships are shown in this illustration. 
convexHull () 
Constructs the geometry that is the minimal bounding polygon such that all outer angles are convex. 
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 illustration. 
cut (cutter) 
Splits this geometry into a part left of the cutting polyline, and a part right of it. When a polyline or polygon is cut, it is split where it intersects the cutter polyline. Each piece is classified as left of or right of the cutter. This classification is based on the orientation of the cutter line. Parts of the target polyline that do not intersect the cutting polyline are returned as part of the right of result for that input polyline. If a geometry is not cut, the left geometry will be empty (None). 
difference (other) 
Constructs the geometry that is composed only of the region unique to the base geometry but not part of the other geometry. The following illustration shows the results when the red polygon is the source geometry. 
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 illustration. 
distanceTo (other) 
Returns the minimum distance between two geometries. If the geometries intersect, the minimum distance is 0. Both geometries must have the same projection. 
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. This is a 2D comparison only; M and Z values are ignored. Only True relationships are shown in this illustration. 
getArea ({type}, {units}) 
Returns the area of the feature using a measurement type. 
getLength ({measurement_type}, {units}) 
Returns the length of the feature using a measurement type. 
getPart ({index}) 
Returns an array of point objects for a particular part of geometry or an array containing a number of arrays, one for each part. 
intersect (other, dimension) 
Constructs a geometry that is the geometric intersection of the two input geometries. Different dimension values can be used to create different shape types. The intersection of two geometries of the same shape type is a geometry containing only the regions of overlap between the original geometries. For faster results, test if the two geometries are disjoint before calling intersect. 
measureOnLine (in_point, {as_percentage}) 
Returns a measure from the start point of this line to the in_point. 
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 illustration. 
positionAlongLine (value, {use_percentage}) 
Returns a point on a line at a specified distance from the beginning of the line. 
projectAs (spatial_reference, {transformation_name}) 
Projects a geometry and optionally applies a geotransformation. To project, the geometry needs to have a spatial reference, and not have an UnknownCoordinateSystem. The new spatial reference system passed to the method defines the output coordinate system. If either spatial reference is unknown the coordinates will not be changed. The Z and measure values are not changed by the ProjectAs method. 
queryPointAndDistance (in_point, {as_percentage}) 
Finds the point on the polyline nearest to the in_point and the distance between those points. Also returns information about the side of the line the in_point is on as well as the distance along the line where the nearest point occurs. 
snapToLine (in_point) 
Returns a new point based on in_point snapped to this geometry. 
symmetricDifference (other) 
Constructs the geometry that is the union of two geometries minus the instersection of those geometries. The two input geometries must be the same shape type. 
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 illustration. 
union (other) 
Constructs the geometry that is the settheoretic union of the input geometries. The two geometries being unioned must be the same shape type. 
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 illustration. 
Methods
Data Type  Explanation 
Object 
A polygon's boundary is a polyline. A polyline's boundary is a multipoint, corresponding to the endpoints of the line. A point or multipoint's boundary is an empty point or multipoint. 
Parameter  Explanation  Data Type 
distance 
The buffer distance. The buffer distance is in the same units as the geometry that is being buffered. A negative distance can only be specified against a polygon geometry.  Double 
Data Type  Explanation 
Polygon 
The buffered polygon geometry. 
Parameter  Explanation  Data Type 
envelope 
An extent object used to define the clip extent.  Extent 
Data Type  Explanation 
Object 
An output geometry clipped to the specified extent. 
Parameter  Explanation  Data Type 
second_geometry 
A second geometry.  Object 
Data Type  Explanation 
Boolean 
A return Boolean value of True indicates this geometry contains the second geometry. 
Data Type  Explanation 
Object 
The resulting geometry. The convex hull of a single point is the point itself. 
Parameter  Explanation  Data Type 
second_geometry 
A second geometry.  Object 
Data Type  Explanation 
Boolean  A return Boolean value of True indicates the two geometries intersect in a geometry of a lesser shape type. 
Parameter  Explanation  Data Type 
cutter 
The cutting polyline geometry.  PolyLine 
Data Type  Explanation 
Geometry 
A list of two geometries. 
Parameter  Explanation  Data Type 
other 
A second geometry.  Object 
Data Type  Explanation 
Object 
The resulting geometry. 
Parameter  Explanation  Data Type 
second_geometry 
A second geometry.  Object 
Data Type  Explanation 
Boolean  A return Boolean value of True indicates that the two geometries share no points in common. 
Parameter  Explanation  Data Type 
other 
A second geometry.  Object 
Data Type  Explanation 
Double 
The distance between the two geometries. 
Parameter  Explanation  Data Type 
second_geometry 
A second geometry.  Object 
Data Type  Explanation 
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. 
Parameter  Explanation  Data Type 
type  PLANAR measurements reflect the projection of geographic data onto the 2D surface (in other words, they will not take into account the curvature of the earth). GEODESIC, GREAT_ELLIPTIC, LOXODROME, and PRESERVE_SHAPE measurement types may be chosen as an alternative, if desired.
(The default value is GEODESIC)  String 
units  The units in which the area will be calculated. Areal unit of measure keywords: ACRES  ARES  HECTARES  SQUARECENTIMETERS  SQUAREDECIMETERS  SQUAREINCHES  SQUAREFEET  SQUAREKILOMETERS  SQUAREMETERS  SQUAREMILES  SQUAREMILLIMETERS  SQUAREYARDS  String 
Data Type  Explanation 
Double 
The area of the feature. By default, for Projected coordinate systems, area will be returned in the units of the coordinate system, and for Geographic coordinate systems, area will be returned in square meters. 
Parameter  Explanation  Data Type 
measurement_type 
PLANAR measurements reflect the projection of geographic data onto the 2D surface (in other words, they will not take into account the curvature of the earth). GEODESIC, GREAT_ELLIPTIC, LOXODROME, and PRESERVE_SHAPE measurement types may be chosen as an alternative, if desired.
(The default value is GEODESIC)  String 
units  The units in which the length will be calculated. Linear unit of measure keywords: CENTIMETERS  DECIMETERS  FEET  INCHES  KILOMETERS  METERS  MILES  MILLIMETERS  NAUTICALMILES  YARDS  String 
Data Type  Explanation 
Double 
The length of the feature. By default, for Projected coordinate systems, length will be returned in the units of the coordinate system, and for Geographic coordinate systems, length will be returned in square meters. 
Parameter  Explanation  Data Type 
index 
The index position of the geometry.  Integer 
Data Type  Explanation 
Array 
getPart returns an array of point objects for a particular 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. 
Parameter  Explanation  Data Type 
other 
The second geometry.  Object 
dimension  The topological dimension (shape type) of the resulting geometry.
 Integer 
Data Type  Explanation 
Object 
A new geometry (point, multipoint, polyline, or polygon) that is the geometric intersection of the two input geometries. 
Parameter  Explanation  Data Type 
in_point 
A point (PointGeometry or Point) that is used to measure from the start point of the polyline.  PointGeometry 
as_percentage  If False, the measure will be returned as a distance; if True, the measure will be returned as a percentage. (The default value is False)  Boolean 
Data Type  Explanation 
Double 
A distance or percentage. 
Parameter  Explanation  Data Type 
second_geometry 
A second geometry.  Object 
Data Type  Explanation 
Boolean  A return Boolean value of True indicates the intersection of the two geometries has the same dimension as one of the input geometries. 
Parameter  Explanation  Data Type 
value 
The distance along the line. If the distance is less than zero, then the starting point of the line will be returned; if the distance is greater than the length of the line, then the end point of the line will be returned.  Double 
use_percentage  The distance may be specified as a fixed unit of measure or a ratio of the length of the line. If True, value is used as a percentage; if False, value is used as a distance. For percentages, the value should be expressed as a double from 0.0 (0%) to 1.0 (100%). (The default value is False)  Boolean 
Data Type  Explanation 
PointGeometry 
The point on the line at a specified distance from the beginning of the line. 
Parameter  Explanation  Data Type 
spatial_reference 
The new spatial reference. This can be a SpatialReference object or the coordinate system name.  SpatialReference 
transformation_name  The geotransformation name.  String 
Data Type  Explanation 
Object 
The projected geometry. 
Parameter  Explanation  Data Type 
in_point 
The input point (PointGeometry or Point).  PointGeometry 
as_percentage  If False, the measure will be returned as a distance; if True, the measure will be returned as a percentage. (The default value is False)  Boolean 
Data Type  Explanation 
tuple 
Returns a tuple that includes the following:

Parameter  Explanation  Data Type 
in_point 
A point (PointGeometry or Point) to be snapped to the line.  PointGeometry 
Data Type  Explanation 
PointGeometry 
The snapped point. 
Parameter  Explanation  Data Type 
other 
A second geometry.  Object 
Data Type  Explanation 
Object 
The resulting geometry. 
Parameter  Explanation  Data Type 
second_geometry 
A second geometry.  Object 
Data Type  Explanation 
Boolean  A return Boolean value of True indicates the boundaries of the geometries intersect. 
Parameter  Explanation  Data Type 
other 
A second geometry.  Object 
Data Type  Explanation 
Object 
The resulting geometry. 
Parameter  Explanation  Data Type 
second_geometry 
A second geometry.  Object 
Data Type  Explanation 
Boolean  A return Boolean value of True indicates this geometry is contained within the second geometry. 
Code Sample
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
# Run the CopyFeatures tool, setting the output to the geometry object.
# geometries is returned as a list of geometry objects.
geometries = arcpy.CopyFeatures_management("c:/data/streets.shp",
arcpy.Geometry())
# Walk through each geometry, totalling the length
length = 0
for geometry in geometries:
length += geometry.length
print("Total length: {0}".format(length))