[Python] Degrees to Cardinal direction

deg_to_cardinal.py

def degrees_to_cardinal(degrees):
    '''
    Return the cardinal direction representing a given 'degrees'
    '''
    cardinal = ['N', 'NNE', 'NE', 'ENE', 'E', 'ESE', 'SE', 'SSE',
                'S', 'SSW', 'SW', 'WSW', 'W', 'WNW', 'NW', 'NNW']
    cardinal_len = len(cardinal)
    ix = round(degrees / (360.0 / cardinal_len))
    return cardinal[ix % cardinal_len]

Updated the original to integrate the changes described in this comment, and to increase readability. I doubt the change from calling len() twice will make any meaningful difference, I just didn't like calling the same function twice like that.