Python Scripting: Let the Snake take a bite out of Time

Slithery-Smooth GIS Process Automation

Martin County Property Appraiser’s Office

John Watterson – GIS Specialist

What is Python?

• Free open source programming language used in numerous fields, not just GIS

• Non-profit foundation: www.python.org

• Embraced by ESRI for the long haul

History of Python at the PAO

• Since 2008

• Easy to learn

• Clear and logical syntax

Basic benefits of using Python in ArcGIS

• Saves work time; and therefore money

• Perfect for automating redundant geoprocessing

• No programming experience required

Basic benefits of using Python in ArcGIS continued

• Elimination of human error

• Versatility: Can run in ArcToolbox

• Increased productivity; Scheduled tasks

Return on Investment

• Can be huge

• Martin County Property Appraiser’s Office uses 12 Python Scripts

What the experts are saying

• Adena Schutzberg of Directions Magazine: Scripting = understanding building blocks of GIS

• Jack Dangermond: Python, Python, Python

• Python scripting – A sought-after skill in the GIS job marketplace

• “Yes, You Need to Code” blog article

Starting point for writing scripts

• ArcGIS Desktop Help – A valuable resource

• Locate favorite tools in ArcToolbox and right click

PDF tax maps to web script

Standard lines of Python code

Script finished successfully message

Do the math!

2 hours manually x 12 months =

24 hours saved or 3 working days per year!

PDF tax maps to web script

Value Annotation Script

Do the math!

2 hours manually x 2 times a week x 5.5 month valuation period (22 weeks) =

88 hours saved or 11 working days per year!

Value Annotation Script

Neighborhood script

Do the math!

30 minutes manually x 2 times a year = 1 hour a year

Neighborhood script

CAMA shapefile to web script

CAMA shapefile to web script

45 minutes manually x 12 times a year =

9 hours saved a year or approximately 1 work day per year!

Do the math!

Do the Math!!

With all the scripts we run at the PAO, Python has saved

me 1 month per year!

Python command Line in ArcGIS

• Open right in ArcMap

• Start typing Python commands

• Auto-complete feature

• Walk through help window

Add-ins with Python

• New to ArcGIS 10.1

• Extending the ArcGIS interface

• So what’s next?

Python advantages over ModelBuilder

• Visualization of code

• Model Builder (MB) has no mapping module • Limited in advanced programming methods(MB)

• Run outside of ArcGIS

• Suitable for writing complex script workflows

• More Help

Course resources

• Geospatial Training Services: www.geospatialtraining.com

• ESRI:

www.esri.com/training/main

GIS Python books

• “Python Scripting for ArcGIS”, Zanderbergen

• “A Python Primer for ArcGIS”, Jennings

• “Programming ArcGIS 10.1 with Python Cookbook”, Pimpler

• “Python Geospatial Development”, Westra

• “GIS Tutorial for Python Scripting”, Allen

Questions or Comments