Book Image

Mastering Geospatial Development with QGIS 3.x - Third Edition

By : Shammunul Islam, Simon Miles, Kurt Menke, GISP, Richard Smith Jr., GISP, Luigi Pirelli, John Van Hoesen, GISP
Book Image

Mastering Geospatial Development with QGIS 3.x - Third Edition

By: Shammunul Islam, Simon Miles, Kurt Menke, GISP, Richard Smith Jr., GISP, Luigi Pirelli, John Van Hoesen, GISP

Overview of this book

QGIS is an open source solution to GIS and widely used by GIS professionals all over the world. It is the leading alternative to proprietary GIS software. Although QGIS is described as intuitive, it is also, by default, complex. Knowing which tools to use and how to apply them is essential to producing valuable deliverables on time. Starting with a refresher on the QGIS basics and getting you acquainted with the latest QGIS 3.6 updates, this book will take you all the way through to teaching you how to create a spatial database and a GeoPackage. Next, you will learn how to style raster and vector data by choosing and managing different colors. The book will then focus on processing raster and vector data. You will be then taught advanced applications, such as creating and editing vector data. Along with that, you will also learn about the newly updated Processing Toolbox, which will help you develop the advanced data visualizations. The book will then explain to you the graphic modeler, how to create QGIS plugins with PyQGIS, and how to integrate Python analysis scripts with QGIS. By the end of the book, you will understand how to work with all aspects of QGIS and will be ready to use it for any type of GIS work.
Table of Contents (18 chapters)
Title Page
Copyright and Credits
About Packt
Contributors
Preface
Index

Chapter 11. PyQGIS Scripting

This chapter is focused on a specific use case or user. QGIS can be used in many different ways, and the GIS user is an eclectic user who has many different ways to interact with data and QGIS tools. The main focus of this chapter is a user who has an algorithm and wants to integrate it with QGIS.

An algorithm can be an external program, such as a water-modeling tool, or a Processing Toolbox's set of instructions.

It's possible to interact with QGIS in many different ways, from experimenting with PyQGIS in the Python console to creating plugins that control events generated by QGIS. This chapter will give you an overview of the following topics:

  • Where to learn Python basics
  • How to load layers
  • Vector structure
  • Iterating over features
  • Editing features
  • Running Processing Toolbox algorithms
  • Interacting with map canvas