Welcome to the Wonderful world of GIS programing!

1. Intro to Python Welcome to the Wonderful world of GIS programing!

2. Topics • A brief history of GIS programing • What is Python? • What is PythonWin? • Basics of Python

3. Software Year Data Format 1980’s Coverage Arc/Info 1990’s ArcView Shapefile 2000’s 2010 Geodatabase Geodatabase ArcGIS 8 & 9 ArcGIS 10 Brief history of ESRI’s GIS software evolution

4. Programming language • SML was used for PC ArcInfo • AMLwas used for Arc/INFO 7.x • Avenue was used for ArcView 3.x • Visual Basic for Application (VBA) is for ArcGIS 8 & 9& packaged with it • Python for ArcGIS10

5. What is Python? • An object oriented scripting language • Cross-platform: meaning portable & will run on Windows, Unix, and Linux • Python is fully embraced by ESRI at ArcGIS 10 • Comes bundled with ArcGIS • Free

6. Programming Environments • Python files are text files (.py extension) • Python code can be written in • PythonWin is the preferred way!

7. PythonWin Interface • PyhonWin created specifically for windows with common tools & menus • Windows look and feel • 3 windows: • a. Application window • b. Script window • c. Interactive window

8. PythonWin: Script Window • Script window is for writing, saving, & executing code • Python scripts are saved with .py extension. Ex: (Test.py)

9. PythonWin: Interactive Window • Interactive window is for testing code and report errors messages • Also report the output of print statement

10. PythonWin: Application/main window Run Script Check Script Script ran successfully

11. Basic Python syntax • Comments • Variables • Strings • Numbers

12. Comments • Lines of code that serve as documentation: • Non-executable • Use a # or ## • It’s a must for your lab Example: # Name: John Denver # Date: January 2012 Block of code can be commented -- Highlight the block of code in the script window -- Right click>Source Code>Comment out region

13. Python Statements Lines of code that perform a task print- sends output to the interactive window import – import a module Example: print “Welcome to Python world” import math (import math module)

14. Variables • Variables store values of different types first = ”Bob” last = “Brown” age = 30 height = 5.6 source = “C:/Exercises/Auburn.gdb” • Variables are case sensitive Num = 500 & num = 5000 (2 variables) • Variables are dynamically type --do not have to declare the variable -- don’t have to assign a data type

15. Strings • An ordered collection of characters • Can be surrounded by double (“”) or single (‘’) quotes message = “Welcome to Python” input = “C:/GIS222/Auburn.gdb/roads”

16. Manipulating Strings Strings can be concatenated f1 = “C:/GIS222/Auburn/roads” f2 = “.shp” Data = f1 + f2 Result= “C:/GIS222/Auburn/roads.shp” Strings can be repeated s1 = “Ha!” s1*3 Result= “Ha!Ha!Ha!”

17. Common String Functions f1 = “AUBURN.shp” f1.upper() Result: “AUBURN.SHP” Upper, lower, capitalize,……….. f1.lower() Result: “auburn.shp” • f1.capitalize() • Result: “Auburn.shp • f1.replace(“AUBURN”, “OWASCO”) • Result: “OWASCO.shp” There are many more; find them by typing object.

18. Built-in Python Functions 1. len() returns the length of a string or a list f1 = “AUBURN.shp” len(f1) Result: 10 2. round() returns a rounded number xCoord = 450,000.2345 round(xCoord) Result: 450,000 3. str() converts an integer to a string zone = 18 strzone = str(zone) print “UTM Zone” + strzone

19. Other Functions to convert values 1. float() returns a floating point value float(“10.0”) Result: 10.0 2. int() returns an integer value int(“10”) Result: 10 3. str() converts an integer to a string str(18) Result: “18” print “UTM Zone” + str(18)

20. Getting user input num = input(“Enter you age: “) 2. str = raw_input(“Enter your name: “) You can always check your input with print num Or print str

21. Python Tutorial ArcGIS Resources Center: Search: “What is Python”

22. Let’s try it!