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
Customer Feedback

Chapter 3. Editing Vector Data

In this chapter, we will cover the following recipes:

  • Creating a vector layer in memory

  • Adding a point feature to a vector layer

  • Adding a line feature to a vector layer

  • Adding a polygon feature to a vector layer

  • Adding a set of attributes to a vector layer

  • Adding a field to a vector layer

  • Joining a shapefile attribute table to a CSV file

  • Changing vector layer geometry

  • Changing a vector layer feature's attribute

  • Removing data from a vector layer

  • Deleting vector layer feature's attributes

  • Reprojecting a vector layer

  • Converting a shapefile to KML or GeoJSON

  • Merging shapefiles

  • Splitting a shapefile

  • Generalizing a vector layer

  • Dissolving vector features

  • Performing a union on vector shapes

  • Rasterizing a vector layer

  • Exporting a layer to the GeoPackage format