python异常中else的实例用法

while True:
 try:
  x = int(input('请输入X:'))
  y = int(input('请输入Y:'))
  value = x / y
  print('x/y is',value)
 except Exception as e:  # 发生异常时执行
  print('不正确的输入：', e)
  print('请重新输入')
 else:  # 未发生异常时执行
  break

def fetcher(obj, index):
 return obj[index]
 
x = 'spam'
 
try:
 print fetcher(x, 3)
except Exception:
 print 'hhh'
else:
 print 'has no exception'
 print fetcher(x, 2)
 print '---' * 10
 
try:
 print fetcher(x, 4)
except IndexError:
 print 'got exception'
else:
 print 'has no exception'
 print fetcher(x, 2)

m
has no exception
a
------------------------------
got exception