在Python字典中找不到密钥时抛出什么异常？

Question

如果我有:

map = { 'stack':'overflow' }

try:
  map['experts-exchange']
except:                       <--- What is the Exception type that's thrown here?
  print( 'is not free' )

无法在网上找到它.=(

Answer 1

KeyError

如果你在没有try块的情况下在控制台上执行它会告诉你

>>> a = {}
>>> a['invalid']
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
KeyError: 'invalid'
>>> 

Answer 2

KeyError.

>>> x = {'try': 1, 'it': 2}
>>> x['wow']

Traceback (most recent call last):
  File "<pyshell#3>", line 1, in <module>
    x['wow']
KeyError: 'wow'

Answer 3

它叫做KeyError

>>d={1:2}

>>d[2]

Traceback (most recent call last):
  File "<stdin>", line 1, in ?
KeyError: 2