Book Image

QGIS Python Programming Cookbook, Second Edition - Second Edition

By : Joel Lawhead
Book Image

QGIS Python Programming Cookbook, Second Edition - Second Edition

By: Joel Lawhead

Overview of this book

QGIS is a desktop geographic information system that facilitates data viewing, editing, and analysis. Paired with the most efficient scripting language—Python, we can write effective scripts that extend the core functionality of QGIS. Based on version QGIS 2.18, this book will teach you how to write Python code that works with spatial data to automate geoprocessing tasks in QGIS. It will cover topics such as querying and editing vector data and using raster data. You will also learn to create, edit, and optimize a vector layer for faster queries, reproject a vector layer, reduce the number of vertices in a vector layer without losing critical data, and convert a raster to a vector. Following this, you will work through recipes that will help you compose static maps, create heavily customized maps, and add specialized labels and annotations. As well as this, we’ll also share a few tips and tricks based on different aspects of QGIS.
Table of Contents (16 chapters)
QGIS Python Programming Cookbook - Second Edition
About the Author
About the Reviewer
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Loading a vector layer from a file sample

Vector data stored in a local file is one of the most common geospatial data formats. Vector data typically stores geometry with associated attributes. In this recipe, we'll load a vector data file, in this case a shapefile, as a vector layer in QGIS.

Getting ready

For ease of following the examples in this book, it is recommended that you create a directory called qgis_data in your root or user directory,which will provide a short pathname. This setup will help prevent the occurrence of any frustrating errors resulting from path-related issues on a given system. In this recipe, and others, we'll use a point shapefile of the New York City museums, which you can download from

Unzip this file and place the shapefile's contents in a directory named nyc within your qgis_data directory.

How to do it...

Now, we'll walk through the steps of loading a shapefile and adding it to the map...