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.

 

[Fredrik Lundh]

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>

 

[Ben Finney]

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.

 

[Theerasak Photha]

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

 

[Ben Finney]

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?

 

[Theerasak Photha]

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