Python for ArcGIS

Preface
Acknowledgements
Contents
Chapter 1: Introduction
	1.1 Python and GIS
	1.2 Sample Data and Scripts
	1.3 GIS Data Formats
		1.3.1 GRID Raster
		1.3.2 Shapefile
		1.3.3 dBASE Files
		1.3.4 Layer Files
		1.3.5 Geodatabase
	1.4 An Introductory Example
	1.5 Organization of This Book
	1.6 Key Terms
Chapter 2: Beginning Python
	2.1 Where to Write Code
	2.2 How to Run Code in PythonWin and PyScripter
	2.3 How to Pass Input to a Script
	2.4 Python Components
		2.4.1 Comments
		2.4.2 Keywords
		2.4.3 Indentation
		2.4.4 Built-in Functions
		2.4.5 Variables, Assignment Statements, and Dynamic Typing
		2.4.6 Variables Names and Tracebacks
		2.4.7 Built-in Constants and Exceptions
		2.4.8 Standard (Built-in) Modules
	2.5 Key Terms
	2.6 Exercises
Chapter 3: Basic Data Types: Numbers and Strings
	3.1 Numbers
	3.2 What Is a String?
	3.3 String Operations
		3.3.1 Find the Length of Strings
		3.3.2 Indexing into Strings
		3.3.3 Slice Strings
		3.3.4 Concatenate Strings
		3.3.5 Check for Substring Membership
	3.4 More Things with Strings (a.k.a. String Methods)
	3.5 File Paths and Raw Strings
	3.6 Unicode Strings
	3.7 Printing Strings and Numbers
	3.8 Key Terms
	3.9 Exercises
Chapter 4: Basic Data Types: Lists and Tuples
	4.1 Lists
		4.1.1 Sequence Operations on Lists
		4.1.2 List Methods
		4.1.3 The Built-in range Function
		4.1.4 Copying a List
	4.2 Tuples
	4.3 Syntax Check and Tracebacks
	4.4 Key Terms
	4.5 Exercises
Chapter 5: ArcGIS and Python
	5.1 ArcToolbox
	5.2 ArcGIS Python Resources
	5.3 Exporting Models
	5.4 Working with GIS Data
	5.5 ArcGIS + Python = arcpy
	5.6 arcpy Functions
	5.7 Environment Settings
	5.8 Key Terms
	5.9 Exercises
Chapter 6: Calling Tools with Arcpy
	6.1 Calling Tools
	6.2 Help Resources
		6.2.1 Tool Help
		6.2.2 Code Snippets
	6.3 Tool Parameters
		6.3.1 Linear Units
		6.3.2 Python Expressions as Inputs
		6.3.3 Multivalue Inputs
		6.3.4 Optional Parameters
	6.4 Return Values and Result Objects
	6.5 Spatial Analyst Toolbox
		6.5.1 Calling Spatial Analyst tools
		6.5.2 Importing spatial analyst
		6.5.3 Raster Calculator
	6.6 Temporary Feature Layers
	6.7 Using Variables for Multiple Tool Calls
	6.8 Calling Custom Tools
	6.9 A Word About Old Scripts
	6.10 Discussion
	6.11 Key Terms
	6.12 Exercises
Chapter 7: Getting User Input
	7.1 Hard-coding versus Soft-coding
	7.2 Using GetParameterAsText
	7.3 Using sys.argv
	7.4 Missing Arguments
	7.5 Argument Spacing
	7.6 Handling File Names and Paths with os Module Functions
		7.6.1 Getting the Script Path
	7.7 Key Terms
	7.8 Exercises
Chapter 8: Controlling Flow
	8.1 Outlining Workflow
	8.2 Key Terms
	8.3 Exercises
Chapter 9: Decision-Making and Describing Data
	9.1 Conditional Expressions
		9.1.1 Comparison Operators
		9.1.2 Equality vs. Assignment
		9.1.3 Logical Operators
		9.1.4 Membership Operators
	9.2 ArcGIS Tools That Make Selections
		9.2.1 Select by Attributes and Temporary Feature Layers
	9.3 Getting a Description of the Data
		9.3.1 Describe Object Properties
		9.3.2 Lists of Properties
		9.3.3 Using Specialized Properties
		9.3.4 Compound vs. Nested Conditions
		9.3.5 Testing Conditions
	9.4 Required and Optional Script Input
	9.5 Creating Output Directories
	9.6 Key Terms
	9.7 Exercises
Chapter 10: Repetition: Looping for Geoprocessing
	10.1 Looping Syntax
		10.1.1 WHILE-Loops
		10.1.2 FOR-Loops
	10.2 Nested Code Blocks
	10.3 Directory Inventory
	10.4 Indentation and the TabNanny
	10.5 Key Terms
	10.6 Exercises
Chapter 11: Batch Geoprocessing
	11.1 List GIS Data
	11.2 Specify Data Name and Type
	11.3 List Fields
	11.4 Administrative Lists
	11.5 Batch Geoprocess Lists of Data
	11.6 Debug: Step Through Code
	11.7 Key Terms
	11.8 Exercises
Chapter 12: Additional Looping Functions
	12.1 List Comprehension
	12.2 The Built-in enumerate Function
	12.3 The Built-in zip Function
	12.4 Walking Through Subdirectories
	12.5 Key Terms
	12.6 Exercises
Chapter 13: Debugging
	13.1 Syntax Errors
	13.2 Exceptions
	13.3 Logic Errors
	13.4 PythonWin Debugging Toolbar
		13.4.1 Using Breakpoints
	13.5 Running in Debug Mode
	13.6 PyScripter Debugging Toolbar
	13.7 Debugging Tips
	13.8 Key Terms
	13.9 Exercises
Chapter 14: Error Handling
	14.1 try/except Structures
		14.1.1 Using Named Exceptions
		14.1.2 Multiple except Blocks
		14.1.3 Error Handling Gotcha
	14.2 Geoprocessing and Error Handling
		14.2.1 Getting Geoprocessing Messages
		14.2.2 The arcpy Named Exception
	14.3 Catching Exceptions in Loops
	14.4 Discussion
	14.5 Key Terms
	14.6 Exercises
Chapter 15: User-Defined Functions
	15.1 A Word About Function Words
		15.1.1 How It Works
		15.1.2 The Docstring
	15.2 Custom Functions with Arguments
		15.2.1 Script Arguments vs. Functions Arguments
		15.2.2 Optional Arguments
	15.3 Returning Values
		15.3.1 A Common Mistake: Where Did the None Come from?
		15.3.2 Returning Multiple Values
	15.4 When to Write Functions
		15.4.1 Where to Define Functions
	15.5 Variables Inside and Outside of Functions
		15.5.1 Mutable Arguments Can Change
		15.5.2 Pass in Outside Variables
	15.6 Key Terms
	15.7 Exercises
Chapter 16: User-Defined Modules
	16.1 Importing User-Defined Modules
	16.2 Using Functions in Another Module
	16.3 Modifying User-Defined Modules (Reload!)
	16.4 Am I the Main Module? What’s My Name?
	16.5 Time Handling Example
	16.6 Summary
	16.7 Key Terms
	16.8 Exercises
Chapter 17: Reading and Writing with Cursors
	17.1 Introduction to Cursors
	17.2 Reading Rows
	17.3 The Field Names Parameter
	17.4 The Shape Field and Geometry Tokens
	17.5 Looping with Cursors
	17.6 Locking
		17.6.1 The del Statement
		17.6.2 The with Statement
	17.7 Update Cursors
	17.8 Insert Cursors
		17.8.1 Inserting Geometric Objects
	17.9 Selecting Rows with SQL
	17.10 Key Terms
	17.11 Exercises
Chapter 18: Dictionaries
	18.1 Dictionary Terms and Syntax
		18.1.1 Access by Key, Not by Index
		18.1.2 Conditional Construct vs. Dictionary
		18.1.3 How to Modify: Update/Add/Delete Items
	18.2 Dictionary Operations and Methods
		18.2.1 Does It Have That Key?
		18.2.2 Listing Keys, Values, and Items
		18.2.3 Looping Through Dictionaries
	18.3 Populating a Dictionary
		18.3.1 Dictionaries and Cursors
	18.4 Discussion
	18.5 Key Terms
	18.6 Exercises
Chapter 19: Reading and Writing Text Files
	19.1 Working with file Objects
		19.1.1 The WITH Statement
		19.1.2 Writing Text Files
		19.1.3 Safe File Reading
		19.1.4 The os Working Directory vs. the arcpy Workspace
		19.1.5 Reading Text Files
	19.2 Parsing Line Contents
		19.2.1 Parsing Field Names
	19.3 Modifying Text Files
		19.3.1 Pseudocode for Modifying Text Files
		19.3.2 Working with Tabular Text
	19.4 Pickling
	19.5 Discussion
	19.6 Key Terms
	19.7 Exercises
Chapter 20: Working with HTML and KML
	20.1 Working with HTML
		20.1.1 Specifying Links
		20.1.2 Embedding Images
		20.1.3 HTML Lists
		20.1.4 HTML Tables
		20.1.5 Writing HTML with Python
		20.1.6 Parsing HTML with BeautifulSoup
	20.2 Fetching and Uncompressing Data
		20.2.1 Fetching HTML
		20.2.2 Fetching Compressed Data
		20.2.3 Expanding Compressed Data
	20.3 Working with KML
		20.3.1 The Structure of KML
		20.3.2 Parsing KML
		20.3.3 Converting KML to Shapefile
	20.4 Discussion
	20.5 Key Terms
	20.6 Exercises
Chapter 21: Classes
	21.1 Why Use OOP?
	21.2 Defining a Class
	21.3 Object Initialization and Self
	21.4 Using Class Objects
	21.5 Where to Define a Class
	21.6 Classes Within a Separate User-Defined Module
	21.7 Discussion
	21.8 Key Terms
	21.9 Exercises
Chapter 22: User Interfaces for File and Folder Selection
	22.1 A Simple Interface with raw_input
	22.2 File Handling with tkFileDialog
		22.2.1 Getting File and Directory Names
		22.2.2 Options
			22.2.2.1 File-Handling Options
				File Types
				Initial Directory
				Initial File
				Multiple Files
				Existing Directories
			22.2.2.2 Close the Tk Window
		22.2.3 Opening Files for Reading and Writing
	22.3 Discussion
	22.4 Key Terms
	22.5 Exercises
Chapter 23: ArcGIS Python GUIs
	23.1 Creating a Script Tool
		23.1.1 Printing from a Script Tool
		23.1.2 Making a Script Tool Button
		23.1.3 Pointing to a Script
	23.2 Creating a GUI
		23.2.1 Using Parameter Data Types
		23.2.2 Using Parameter Properties
			23.2.2.1 Type
			23.2.2.2 Direction
			23.2.2.3 Multivalue
			23.2.2.4 Default or Schema
			23.2.2.5 Environment
			23.2.2.6 Filter
			23.2.2.7 Obtained from
			23.2.2.8 Symbology
	23.3 Showing Progress
	23.4 Validating Input
		23.4.1 The ToolValidator Class
			23.4.1.1 Initializing Parameter Objects
			23.4.1.2 An updateMessages Example
			23.4.1.3 An initializeParameters Example
			23.4.1.4 An updateParameters Example
	23.5 Python Toolboxes
		23.5.1 Setting Up Parameters (getParameterInfo)
		23.5.2 Checking for Licenses (isLicensed)
		23.5.3 Validation (updateParameters and updateMessages)
		23.5.4 Running the Code (execute)
		23.5.5 Comparing Tools
	23.6 Discussion
	23.7 Key Terms
	23.8 Exercises
Chapter 24: Mapping Module
	24.1 Map Documents
		24.1.1 Map Name or'CURRENT' Map
		24.1.2 MapDocument Properties
		24.1.3 Saving Map Documents
	24.2 Working with Data Frames
	24.3 Working with Layers
		24.3.1 Moving, Removing, and Adding Layers
		24.3.2 Working with Symbology
	24.4 Managing Layout Elements
	24.5 Discussion
	24.6 Key Terms
	24.7 Exercises
Index