Python Geospatial Development Essentials

Karim Bahgat

• Éditeur: Packt Publishing
• Année: 2015
• ISBN:
  9781782175407
• Édition: 1
• Sujet: Ciencia de la computación
• Sous-sujet: Desarrollo de aplicaciones

Python Geospatial Development Essentials

---

Table of Contents

Python Geospatial Development Essentials

Credits

About the Author

About the Reviewers

www.PacktPub.com

Support files, eBooks, discount offers, and more

Why subscribe?

Free access for Packt account holders

Preface

What this book covers

What you need for this book

Who this book is for

Conventions

Reader feedback

Customer support

Downloading the example code

Errata

Piracy

Questions

1. Preparing to Build Your Own GIS Application

Why reinvent the wheel?

Setting up your computer

Installing third-party packages

Imagining the roadmap ahead

Summary

2. Accessing Geodata

The approach

Vector data

A data interface for vector data

The vector data structure

Computing bounding boxes

Spatial indexing

Loading vector files

Shapefile

GeoJSON

File format not supported

Saving vector data

Shapefile

GeoJSON

File format not supported

Raster data

A data interface for raster data

The raster data structure

Positioning the raster in coordinate space

Nodata masking

Loading raster data

GeoTIFF

File format not supported

Saving raster data

GeoTIFF

File format not supported

Summary

3. Designing the Visual Look of Our Application

Setting up the GUI package

Creating the toolkit building blocks

Themed styling

Basic buttons

Buttons with icons

Toolbars

The Ribbon tab system

The bottom status bar

The layers pane

The Map widget

Pop-up windows

Dispatching heavy tasks to thread workers

Using the toolkit to build the GUI

Testing our application

Summary

4. Rendering Our Geodata

Rendering

Installing PyAgg

A sequence of layers

The MapCanvas drawer

Individual layer renderings

Vector layers

Raster layers

Interactively rendering our maps

Linking the MapView to the renderer

Requesting to render a map

Resizing the map in proportion to window resizing

The LayersPane as a LayerGroup

Adding layers

Editing layers in the LayersPane widget

Click-and-drag to rearrange the layer sequence

Zooming the map image

Map panning and one-time rectangle zoom

A navigation toolbar

Putting it all together

Summary

5. Managing and Organizing Geographic Data

Creating the management module

Inspecting files

Organizing files

Vector data

Splitting

Merging

Geometry cleaning

Raster data

Mosaicking

Resampling

Weaving functionality into the user interface

Layer-specific right-click functions

Defining the tool options windows

Setting up the management tab

Defining the tool options windows

Summary

6. Analyzing Geographic Data

Creating the analysis module

Analyzing data

Vector data

Overlap summary

Buffer

Raster data

Zonal statistics

Weaving functionality into the user interface

Layer-specific right-click functions

Defining the tool options windows

Setting up the analysis tab

Defining the tool options window

Summary

7. Packaging and Distributing Your Application

Attaching an application logo

The icon image file

Assigning the icon

The application start up script

Packaging your application

Installing py2exe

Developing a packaging strategy

Creating the build script

Adding the visual C runtime DLL

Creating an installer

Installing Inno Setup

Setting up your application's installer

Summary

8. Looking Forward

Improvements to the user interface

Saving and loading user sessions

File drag and drop

GUI widgets

Other variations of the user interface

Adding more GIS functionality

Basic GIS selections

More advanced visualization

Online data services

Converting between raster and vector data

Projections

Geocoding

Going the GDAL/NumPy/SciPy route

Expanding to other platforms

Touch devices

Summary

Index

Python Geospatial Development Essentials

Copyright © 2015 Packt Publishing

All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, without the prior written permission of the publisher, except in the case of brief quotations embedded in critical articles or reviews.

Every effort has been made in the preparation of this book to ensure the accuracy of the information presented. However, the information contained in this book is sold without warranty, either express or implied. Neither the author, nor Packt Publishing, and its dealers and distributors will be held liable for any damages caused or alleged to be caused directly or indirectly by this book.

Packt Publishing has endeavored to provide trademark information about all of the companies and products mentioned in this book by the appropriate use of capitals. However, Packt Publishing cannot guarantee the accuracy of this information.

First published: June 2015

Production reference: 1100615

Published by Packt Publishing Ltd.

Livery Place

35 Livery Street

Birmingham B3 2PB, UK.

ISBN 978-1-78217-540-7

www.packtpub.com

Credits

Author

Karim Bahgat

Reviewers

Gregory Giuliani

Jorge Samuel Mendes de Jesus

Athanasios Tom Kralidis

John Maurer

Adrian Vu

Commissioning Editor

Amarabha Banerjee

Acquisition Editors

Larissa Pinto

Rebecca Youé

Content Development Editor

Merwyn D'souza

Technical Editor

Prajakta Mhatre

Copy Editor

Charlotte Carneiro

Project Coordinator

Neha Bhatnagar

Proofreader

Safis Editing

Indexer

Rekha Nair

Production Coordinator

Manu Joseph

Cover Work

Manu Joseph

About the Author

Karim Bahgat holds an MA in peace and conflict transformation from the University of Tromsø in Norway, where he focused on the use of geographic information systems (GIS), opinion survey data, and open source programming tools in conflict studies. Since then, he has been employed as a research assistant for technical and geospatial work at the Peace Research Institute Oslo (PRIO) and the International Law and Policy Institute (ILPI). Karim was part of the early prototyping of the PRIO-GRID unified spatial data structure for social science and conflict research, and is currently helping develop a new updated version (https://www.prio.org/Data/PRIO-GRID/).

His main use of technology, as a developer, has been with Python programming, geospatial tools and mapping, the geocoding of textual data, data visualization, application development, and some web technology. Karim is the author of a journal article publication, numerous data- and GIS-oriented Python programming libraries, the Easy Georeferencer free geocoding software, and several related technical websites, including www.pythongisresources.wordpress.com.

I am very grateful for the detailed feedback, suggestions, and troubleshooting of chapters from the reviewers; the encouragement and guidance from the publisher's administrators and staff, and the patience and encouragement from friends, family, colleagues, and loved ones (especially my inspirational sidekicks, Laura and Murdock). I also want to thank all my teachers at the Chapman University and University of North Dakota, who got me here in the first place. They helped me think out of the box and led me into this wonderful world of geospatial technology.

About the Reviewers

Gregory Giuliani is a geologist with a PhD in environmental sciences (theme: spatial data infrastructure for the environment). He is a senior scientific associate at the University of Geneva (Switzerland) and the focal point for spatial data infrastructure (SDI) at GRID-Geneva. He is the manager of the EU/FP7 EOPOWER project and the work package leader in the EU/FP7 enviroGRIDS and AfroMaison projects, where he coordinates SDI development and implementation. He also participated in the EU/FP7 ACQWA project and is the GRID-Geneva lead developer of the PREVIEW Global Risk Data Platform (http://preview.grid.unep.ch). He coordinates and develops capacity building material on SDI for enviroGRIDS and actively participates and contributes to various activities of the Global Earth Observation System of Systems (GEOSS). Specialized in OGC standards, interoperability, and brokering technology for environmental data and services, he is the coordinator of the Task ID-02 "Developing Institutional and Individual Capacity" for GEO/GEOSS.

Jorge Samuel Mendes de Jesus has 15 years of programming experience in the field of Geoinformatics, with a focus on Python programming, OGC web services, and spatial databases.

He has a PhD in geo...