Creating a projection definition for a Shapefile if it does not exist

You recently downloaded a Shapefile from an Internet resource and saw that the .prj file was not included. You do know, however, that the data is stored in the EPSG:4326 coordinate system as stated on the website from where you downloaded the data. Now the following code will create a new .prj file.

Getting ready

Start up your Python virtual environment with the workon pygeo_analysis_cookbook command:

How to do it...

In the following steps, we will take you through creating a new .prj file to accompany our Shapefile. The .prj extension is necessary for many spatial operations performed by a desktop GIS, web service, or script:

1. Create a new Python file named ch02_04_write_prj_file.py in your /ch02/code/working/ directory and add the following code:

   #!/usr/bin/env python
   # -*- coding: utf-8 -*-
   
   import urllib
   import os
   
   def get_epsg_code(epsg):
      """
      Get the ESRI formatted .prj definition
      usage get_epsg_code...