Assigning Coordinate Systems - Method for ALL ArcGIS Versions!

This method works for 10.0, 10.1, and 10.2 and so I will be using this method exclusively henceforth.
The inclass script 3 on the class plan page has been updated to include this fix.
Homework due 02/21 is now posted in the assignments page

# Step 1:
# Must import the os as follows:
import os
# If you are impporting multiple libraries:
import arcpy, sys, os

# Step 2:
# Specify the ArcGIS installation directory and then the path to the specific coordinate system needed:
MyNAD83System = os.path.join(arcpy.GetInstallInfo()["InstallDir"], "Coordinate Systems\GeographicCoordinate Systems\North America\Nad 1983")
# The highlighted section above is the path to the specific coordinate system. In the example NAD83 is used.