In this book, you will find a number of styles of text that distinguish between different kinds of information. Here are some examples of these styles, and an explanation of their meaning.

Code words in text are shown as follows: "We can then convert these to Shapely geometric objects using the shapely.wkt module."

A block of code is set as follows:

import osgeo.ogr
shapefile = osgeo.ogr.Open("TM_WORLD_BORDERS-0.3.shp")
layer = shapefile.GetLayer(0)

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

from pysqlite2 import dbapi as sqlite
conn = sqlite.connect("...")
conn.enable_load_extension(True)
conn.execute('SELECT load_extension("libspatialite-2.dll")')
curs = conn.cursor()

Any command-line input or output is written as follows:

>>> import sqlite3
>>> conn = sqlite3.connect(":memory:")
>>> conn.enable_load_extension(True)

New terms and important words are shown in bold. Words that you see on the screen, in menus or dialog boxes for example, appear in the text like this: "If you want, you can change the format of the downloaded data by clicking on the Modify Data Request hyperlink".