1. Writing Geoprocessing Scripts With ArcGIS
Lecture 10
04/1/2008
ArcGIS 9 introduces scripting support for many of today’s most popular scripting
environments, such as Python, VBScript, JScript™, and Perl.
Python is an easy-tolearn
language similar to C. Python has the ease of use of a scripting language,
along with the programming capabilities of a complete developer language.
Moreover, Python is platform independent and can operate on a variety of
operating systems including UNIX®, Linux®, and Windows.

2. GIS System

3. Development tool
The ArcGIS system is built and extended using ArcObjects software components. ArcObjects includes a wide variety of programmable components.
Developers work with ArcObjects using standard programming frameworks to extend ArcGIS Desktop, build custom applications with ArcGIS Engine, and implement server GIS applications for various enterprise purposes using ArcGIS sever.
The ArcGIS system is built and extended using ArcObjects software components. ArcObjects includes a wide variety of programmable components, ranging from fine-grained objects (for example, individual geometry objects) to coarse-grained objects (for example, a map object to interact with existing
ArcMap documents), which aggregate comprehensive GIS functionality for developers.
Developers work with ArcObjects using standard programming frameworks to extend ArcGIS Desktop, build custom applications with ArcGIS Engine, and implement server GIS applications for various enterprise purposes using ArcGIS sever.

4. VBA and Python

10. ArcMap Objects Link

12. A new
ArcObjects™ component, the geoprocessor, manages all the geoprocessing functions
available within ArcGIS. It is an object that provides a single access point
and environment for the execution of any geoprocessing tool in ArcGIS, including
extensions. The geoprocessor implements automation using the COM
IDispatch interface, making it possible for interpretative and macro languages to
access the more than 400 available tools.
GpDispatch is
the COM name for the geoprocessor
IDispatch object.
In Python, the
Dispatch method on the win32com
module’s client object is used to create the
geoprocessor, while Visual Basic and
VBScript use the CreateObject function.

17. Python Basics

20. Variable index Word[0]=‘H’ Word[2:4]=‘lp’ Word[:3]=‘Hel’
Word[-2:-4]=‘el’
Word[-3:]=‘lpA’

26. Scripts Examples

27. Does not work in your computer

28. Create a new geoprocessor
Add the toolbox

29. Extract the radar rainfall using raingauges location.
Objective: compare the radar and rain gauge rainfall measurements
Data source:
Polygon-feature class of radar rainfall (>10k files);
Point-feature of rain gauge locations (50 gauges);
Method: interception
Final format: all values are stored at one *.txt file.

30. Study Area

34. Exploring more ArcGIS
Teaching yourself.