Difference between unindexable and unsubscriptable

Jackson

What is the difference between "object is unindexable" and "object is
unsubscriptable"?

I would like to test if an object can accept: obj[0]

>>from sets import Set
Set([1,2])[0]

TypeError: unindexable object

>>3[0]

TypeError: unsubscriptable object

It seems like each of these errors can be replaced with a single type error.

Oct 11 '06 #1

Fredrik Lundh

Jackson wrote:

What is the difference between "object is unindexable" and "object is
unsubscriptable"?

I would like to test if an object can accept: obj[0]

>>from sets import Set
>>Set([1,2])[0]

TypeError: unindexable object

>>3[0]

TypeError: unsubscriptable object

It seems like each of these errors can be replaced with a single type error.

the message string is not part of the error type, and may change between
versions. just catch the TypeError and be done with it.

</F>

Oct 11 '06 #2

Ben Finney

Jackson <ja*****@hotmail.comwrites:

I would like to test if an object can accept: obj[0]

Then do so. Use the object in the way you want to use it, and catch
any exceptions that you want to handle.

>>from sets import Set
>>Set([1,2])[0]

TypeError: unindexable object

>>3[0]

TypeError: unsubscriptable object

It seems like each of these errors can be replaced with a single
type error.

Well, they are both merely instances of TypeError, just with a
different message. Catching 'TypeError' will catch either of them.

I agree, though, that it would be preferable to have the same message
for these two cases that appear to be saying the same thing.

--
\ "The trouble with eating Italian food is that five or six days |
`\ later you're hungry again." -- George Miller |
_o__) |
Ben Finney

Oct 11 '06 #3

Theerasak Photha

On 10/11/06, Ben Finney <bi****************@benfinney.id.auwrote:

Jackson <ja*****@hotmail.comwrites:

I would like to test if an object can accept: obj[0]

Then do so. Use the object in the way you want to use it, and catch
any exceptions that you want to handle.

I'm trying to learn about style conventions in Python. How would use
of getattr compare?

-- Theerasak

Oct 11 '06 #4

Ben Finney

"Theerasak Photha" <ha********@gmail.comwrites:

On 10/11/06, Ben Finney <bi****************@benfinney.id.auwrote:

Jackson <ja*****@hotmail.comwrites:

I would like to test if an object can accept: obj[0]

Then do so. Use the object in the way you want to use it, and catch
any exceptions that you want to handle.

I'm trying to learn about style conventions in Python. How would use
of getattr compare?

I'm having trouble knowing what you need explained.

You have available to you an interactive Python interpreter, and the
documentation. Can you show us some sessions in the interpreter that
you still find confusing after you read the relevant documentation?

--
\ "When I get new information, I change my position. What, sir, |
`\ do you do with new information?" -- John Maynard Keynes |
_o__) |
Ben Finney

Oct 11 '06 #5

Theerasak Photha

On 10/11/06, Ben Finney <bi****************@benfinney.id.auwrote:

I'm trying to learn about style conventions in Python. How would use
of getattr compare?

I'm having trouble knowing what you need explained.

You have available to you an interactive Python interpreter, and the
documentation. Can you show us some sessions in the interpreter that
you still find confusing after you read the relevant documentation?

Don't worry, I got it now. (Ah Perl...how you warped my mind...)

-- Theerasak

Oct 11 '06 #6