Using a `del` statement only with a tuple or string indexed gets the error message with `doesn't` instead of `does not`

[hyperkai]

Bug report

Bug description:

Using a del statement only with a tuple indexed gets the error message with doesn't instead of does not as shown below:

v = ('a', 'b', 'c')

v[1] = 'A'
# TypeError: 'tuple' object does not support item assignment

v[1:3] = ['A', 'B']
# TypeError: 'tuple' object does not support item assignment

del v[1]
# TypeError: 'tuple' object doesn't support item deletion
                          # ↑↑↑↑↑↑↑
del v[1:3]
# TypeError: 'tuple' object does not support item deletion

And, using a del statement only with a string indexed gets the error message with doesn't instead of does not as shown below:

v = 'abc'

v[1] = 'A'
# TypeError: 'str' object does not support item assignment

v[1:3] = ['A', 'B']
# TypeError: 'str' object does not support item assignment

del v[1]
# TypeError: 'str' object doesn't support item deletion
                        # ↑↑↑↑↑↑↑
del v[1:3]
# TypeError: 'str' object does not support item deletion

CPython versions tested on:

3.13

Operating systems tested on:

Windows

[skirpichev]

What's wrong?

[hyperkai]

Consistency.

[skirpichev]

I don't think it's a good reason for similar changes (per import this).

[pochmann3]

What in import this are you referring to?

[skirpichev]

Ah, sorry. This was a quirk of my memory to count the second chapter of PEP 8 as being somehow in import this. Maybe, it should;-)

Anyway, both forms appear in error messages. There is nothing incorrect, we have no strict rules to prefer something here.

[picnixz]

We did change error messages to make them "better" (and recently in some sysmodule IIRC, and other messages during parsing as well (this is a 3.14 highlight)), and I think consistency would help. OTOH, I know that people check for messages in their tests, and changing the message could be bothersome.

Note that we do check "object does not support item assignment" in some doctests in tutorial.rst.