Sara Johnson said unto the world upon 07/08/2007 01:34 AM:
> Sorry, this is probably too general a question, but I can't find
> any specific information on it. What exactly is a "key error" and
> how do I clear it?
>
> I entered something like this:
>
> abcd=h[key]['ABCD']
>
> and when I run it I'm getting
>
> KeyError: 'ABCD'
>
> What does this mean?
>
> Thanks!
>
Hi Sara,
It means you've tried to access a data structure (most likely a
dictionary) with a key that does not exist in that structure. Witness
>>> my_dict={42:"Six times seven", 1: "The loneliest number"}
>>> my_dict[42]
'Six times seven'
>>> my_dict['42']
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
KeyError: '42'
>>> my_dict[17]
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
KeyError: 17
>>>
It isn't a question of `clearing' it, but of tracking down the wrong
assumption behind your code. It may be that you thought you were using
a key you'd added before and were wrong (my_dict['42'] as opposed to
my_dict[42] shows a common source of that).
But, from your
> abcd=h[key]['ABCD']
I'm guessing that you've got the key-access syntax a bit wrong. Did
you mean
abcd = h['ABCD']
instead?
HTH,
Brian vdB
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