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Transcription

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2 Contents Preface Acknowledgments xz xiv Part 1: Learning the fundamentals of Python and geoprocessing 1 17 Exploring how Python is used Chapter 1: Introducing Python 3 11 Introduction 3 12 Exploring the features of Python 3 13 Comparing scripting vs programming 4 14 Using scripting in ArcGIS 5 15 Python history and versions 5 16 About this book Choosing a Python script editor Chapter 2: Geoprocessing in ArcGIS 21 Introduction 22 What is geoprocessing? 23 A note on ArcObjects 24 Using toolboxes and tools 25 Learning types and categories of tools 26 Running tools using tool dialog boxes 27 Specifying environment settings 28 Using batch processing 29 Using models and ModelBuilder 210 Using scripting 211 Running scripts as tools 212 Converting a model to a script 213 Scheduling a Python script to run at prescribed times

3 vi Contents Chapter 3: Using the Python window Introduction 32 Opening the Python window Writing and running code Getting assistance_ Exploring Python window options Saving your work 37 Loading code into the Python window ^ 54 Chapter 4: Learning Python language fundamentals Introduction Locating Python documentation and resources Working with data types and structures Working with numbers Working with variables and naming Writing statements and expressions Using strings - 48 Using lists Working with Python objects Using functions Using methods Working with strings 413 Working with lists 414 Working with paths Working with modules Controlling workflow using conditional statements Controlling workflow using loop structures Getting user input Commenting scripts Working with code in the PythonWin editor Following coding guidelines 89 90

4 Contents Vl'i Part 2: Writing scripts 93 Chapter 5: Geoprocessing using Python Introduction Using the ArcPy site package _95 53 Importing ArcPy Working with earlier versions of ArcGIS Using tools Working with toolboxes Using functions Using classes Using environment settings Working with tool messages Working with licenses Accessing ArcGIS Desktop Help Chapter 6: Exploring spatial data 61 Introduction 62 Checking for the existence of data 63 Describing data 64 Listing data 65 Using lists in for loops 66 Working with lists 67 Working with tuples 68 Working with dictionaries _131 _132 _133 _ Chapter 7: Manipulating spatial data 71 Introduction_ 72 Using cursors to access data 73 Using SQL in Python 74 Working with table and field names 75 Parsing table and field names 76 Working with text files Chapter 8: Working with geometries 81 Introduction 82 Working with geometry objects 83 Reading geometries 84 Working with multipart features 85 Working with polygons with holes _ 86 Writing geometries 87 Using cursors to set the spatial reference 88 Using geometry objects to work with geoprocessing tools _159 _159 _159 _160 _164 _167 _169 _172 _

5 - viii Contents Chapter 9: Working with rasters Introduction 1 92 Listing rasters 1'' Describing raster properties Working with raster objects 182 _ 95 Working with the ArcPy Spatial Analyst module Using map algebra operators Using the ApplyEnvironment function Using classes of the arcpy sa module Using raster functions to work with NumPy arrays Part 3: Carrying out specialized tasks 195 Chapter 10: Map scripting Introduction Working with the ArcPy mapping module Opening map documents Accessing map document properties and methods Working with data frames Working with layers Fixing broken data sources _ Working with page layout elements Exporting maps Printing maps _ Working with PDFs Creating map books Using sample mapping scripts Chapter 11: Debugging and error handling Introduction 112 Recognizing syntax errors Recognizing exceptions Using debugging Using debugging tips and tricks Error handling for exceptions Raising exceptions 118 Handling exceptions Handling geoprocessing exceptions Using other error-handling methods Watching for common errors

6 Chapter 12: Creating Python functions and classes Introduction Creating functions Calling functions from other scripts _ Organizing code into modules Using classes Working with packages Part 4: Creating and using script tools 269 Chapter 13: Creating custom tools Introduction Why create your own tools? Steps to creating a tool 134 Editing tool code Exploring tool parameters Setting tool parameters Examining an example script tool Customizing tool behavior Working with messages _ Handling messages for stand-alone scripts and tools Customizing tool progress information Running a script in process Introduction Chapter 14: Sharing tools_ Choosing a method for distributing tools _ Handling licensing issues Using a standard folder structure for sharing tools Working with paths 146 Finding data and workspaces Creating a geoprocessing package Embedding scripts and password-protecting tools Documenting tools Example tool: Market analysis Appendix A Data source credits 323 Appendix B Data license agreement 327 Appendix C Installing the data and software 331 Index 337