def average(*args):
sum = 0.0
if len(args)!=0:
for a in args:
sum = a +sum
return sum/len(args)
else:
return sum
print sum
print average()
print average(1, 2)
print average(1, 2, 2, 3, 4)
print r'''"To be, or not to be": that is the question./nWhether it's nobler in the mind to suffer.'''与print r'''"To be, or not to be": that is the question.
Whether it's nobler in the mind to suffer.'''
在练习答案都对，在cmd里面前者不会自动换行/n保留输出，
