Book Image

Python Geospatial Development - Second Edition - Second Edition

By : Erik Westra
Book Image

Python Geospatial Development - Second Edition - Second Edition

By: Erik Westra

Overview of this book

Geospatial development links your data to places on the Earth's surface. Writing geospatial programs involves tasks such as grouping data by location, storing and analyzing large amounts of spatial information, performing complex geospatial calculations, and drawing colorful interactive maps. In order to do this well, you'll need appropriate tools and techniques, as well as a thorough understanding of geospatial concepts such as map projections, datums and coordinate systems. Python Geospatial Development - Second Edition teaches you everything you need to know about writing geospatial applications using Python. No prior knowledge of geospatial concepts, tools or techniques is required. The book guides you through the process of installing and using various toolkits, obtaining geospatial data for use in your programs, and building complete and sophisticated geospatial applications in Python. Python Geospatial Development teaches you everything you need to know about writing geospatial applications using Python. No prior knowledge of geospatial concepts, tools or techniques is required. The book guides you through the process of installing and using various toolkits, obtaining geospatial data for use in your programs, and building complete and sophisticated geospatial applications in Python. This book provides an overview of the major geospatial concepts, data sources and toolkits. It teaches you how to store and access spatial data using Python, how to perform a range of spatial calculations, and how to store spatial data in a database. Because maps are such an important aspect of geospatial programming, the book teaches you how to build your own “slippy map” interface within a web application, and finishes with the detailed construction of a geospatial data editor using Geodjango. Whether you want to write quick utilities to solve spatial problems, or develop sophisticated web applications based around maps and geospatial data, this book includes everything you need to know.
Table of Contents (18 chapters)
Python Geospatial Development
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Sources of geospatial data in vector format


Vector-based geospatial data represents physical features as collections of points, lines, and polygons. Often, these features will have metadata associated with them. In this section, we will look at some of the major sources of free vector-format geospatial data.

OpenStreetMap

OpenStreetMap (http://openstreetmap.org) is a website where people can collaborate to create and edit geospatial data. It describes itself as a "free editable map of the whole world made by people like you."

The following screenshot shows a portion of a street map for Onchan, Isle of Man, based on data from OpenStreetMap:

Data format

OpenStreetMap does not use a standard format such as shapefiles to store its data. Instead, it has developed its own XML-based format for representing geospatial data in the form of nodes (single points), ways (sequences of points that define a line), areas (closed ways that represent polygons), and relations (collections of other elements). Any...