docs: 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)) ]