The Python Shapefile Library (pyshp) provides read and write
support for the ESRI Shapefile format. The Shapefile format is a
popular Geographic Information System vector data format created by
Esri. For more information about this format please read the
well-written "ESRI Shapefile Technical Description - July 1998". The
Esri document describes the shp and shx file formats. However a third
file format called dbf is also required. This format is documented on
the web as the "XBase File Format Description" and is a simple
file-based database format created in the 1960's. Both the Esri and
XBase file-formats are very simple in design and memory efficient which
is part of the reason the shapefile format remains popular despite the
numerous ways to store and exchange GIS data available today.