1. Overview Cursors arcpy.da module Geometrys Arrays SpatialReferences
Licensing and Installation

2. arcpy.*Cursor functions

3. SearchCursor Syntax

4. SearchCursor Example

5. Update Cursor Syntax

6. Update cursor example

7. Insert Cursor Syntax

8. InsertCursor Example

9. Insert/Update and Locked data
Can not Insert/Update if data is locked
Feature class or table can be locked if it is:
Part of a map in an MXD that is open in ArcMap
Part of a workspace being viewed by ArcCatalog
Best practices include:
Exit ArcGIS applications when running scripts that create or modify tables or feature classes
Delete cursor objects when you have finished using them …

10. The Data Access (da) module
New at 10.1
arcpy.da.Walk( ) – an ArcGIS-aware version of os.path.walk ( )

11. SearchCursor Function and Class
arcpy Function
arcpy.da Class

12. SearchCursor Function and Class Example
arcpy.SearchCursor Function syntax
SearchCursor (dataset, {where_clause}, {spatial_reference}, {fields}, {sort_fields})
262 sec for Function
0.66 sec for Class
~ 400 times faster in this case
arcpy.da.SearchCursor Class syntax
SearchCursor (in_table, field_names, {where_clause}, {spatial_reference}, {explode_to_points}, {sql_clause})
Output:

13. The Geometry Class

14. Geometry Properties

15. Geometry Methods … and clip contains convexHull crosses difference
disjoint
distanceTo
equals
getArea
getLength
getPart
intersect
overlaps
positionAlongLine
projectAs
symmetricDifference
touches
union
within

16. Reading geometries

17. Writing geometries using Python
Problem:
We have a text file containing a line identifier and
x,y coordinates that we would like to use to create
polylines in an new feature class similar to an
existing feature class
Solution:
Create a script tool that has two inputs (text file name and
template feature class) and one output feature class.
The script will
- Create a new feature class based on the template feature class
- Read the ID and coords for each line from the text file
- Use an insert cursor to add each line to the new feature class

18. Before writing polylines to a feature class …
… need some other background
Polylines are created from an array of points
How is a point created?
How is an array points created?

19. Point and PointGeometry Classes

20. PointGeometry Class

21. Array Class

22. Polyline

23. Writing geometries using Python
Input file structure:
For Update/InsertCursor objects, test your scripts on a copy of the dataset. It is sometimes hard to undo modifications to data!

24. Spatial reference and cursors

25. Creating a spatial reference

26. Licensing and Installation

27. Licensing and Installation
Check to see if a license is available
Returns license to license manager
Check out license from license manager
See if requested product is available
Information about installation
Install types that used with GetInstallInfo
Current product license
Legacy … replaced by