Returns a list of subdirectories in a directory.
		This function performed three times better for me than 
		"for root, dirs, files in os.walk(d):
			return dirs"

def getSubdirectories(d):
	'''Returns a list of subdirectories in a directory.
		This function performed three times better for me than 
		"for root, dirs, files in os.walk(d):
			return dirs"
	'''
	return [f for f in os.listdir(d) if os.path.isdir(os.path.join(d, f)) ]