import sys

def y_n_question(question_str):

	yes = {'yes','y', 'ye', ''}
	no = {'no','n'}

	while True:
		sys.stdout.write(question_str + " [Y/n]: ")
		choice = input().lower()
		if choice in yes:
		   return True
		elif choice in no:
		   return False
		else:
		   sys.stdout.write("\nPlease respond with 'yes' or 'no'\n")
		   continue