[issue38605] [typing] PEP 563: Postponed evaluation of annotations: enable it by default before Python 4.0

[Batuhan Taskaya]

Change by Batuhan Taskaya :


--
nosy: +BTaskaya

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue38605] [typing] PEP 563: Postponed evaluation of annotations: enable it by default before Python 4.0

[STINNER Victor]

STINNER Victor  added the comment:

This issue has been discussed during the Language Summit. A quick poll showed 
that the majority is in favor of changing the default in Python 3.9.

Lukasz proposed a PEP update to propose to switch the default in Python 3.9:
https://github.com/python/peps/pull/1371/

For me, the unclear part is which projects would be impacted if the default 
changes?

Someone mentioned attrs, but it seems like attrs is fine:
https://github.com/python-attrs/attrs/issues/288#issuecomment-587265961

In term of workflow, I would _prefer_ to get such incompatible in the very 
beginning of a devcycle, rather than just before the feature freeze. But I 
don't think that it's a blocker issue. Technically, changes are allowed until 
3.9.0 beta1. Moreover, Lukasz is the 3.9 release manager, the author of the PEP 
563 and he is in favor of changing the default in 3.9 :-)

--

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue38605] [typing] PEP 563: Postponed evaluation of annotations: enable it by default before Python 4.0

[Brett Cannon]

Brett Cannon  added the comment:

I personally like 3.10 as the target as that means users had at least 3 years 
to move to move over. Plus we can put a warning in the What's New for 3.9 about 
our plans for 3.10.

--
nosy: +brett.cannon

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue38605] [typing] PEP 563: Postponed evaluation of annotations: enable it by default before Python 4.0

[STINNER Victor]

STINNER Victor  added the comment:

I started a thread on typing-sig:
https://mail.python.org/archives/list/typing-...@python.org/thread/JG4IWHO3TZORNESR6ARXFL6OUZU2BEBX/

--

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue38605] [typing] PEP 563: Postponed evaluation of annotations: enable it by default before Python 4.0

[Barry A. Warsaw]

Change by Barry A. Warsaw :


--
nosy: +barry

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue38605] [typing] PEP 563: Postponed evaluation of annotations: enable it by default before Python 4.0

[Guido van Rossum]

Guido van Rossum  added the comment:

You can bring the deprecation schedule up on discourse or python-dev so more 
folks can let us know whether they'd be okay with 3.9 or 3.10.

--

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue38605] [typing] PEP 563: Postponed evaluation of annotations: enable it by default before Python 4.0

[STINNER Victor]

STINNER Victor  added the comment:

> We never should have mentioned 4.0 as the target date to make this the
default (and only) behavior

I am fine with modifying __future__ documentation to only modify the 
"Mandatory" column to remove Python 4.0, and then close this issue:
https://docs.python.org/dev/library/__future__.html

--

But I like the "PEP 563: Postponed evaluation of annotations", IMHO it would be 
nice to get it as the default behavior :-) It's just a matter of properly 
organize the transition ;-)

--

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue38605] [typing] PEP 563: Postponed evaluation of annotations: enable it by default before Python 4.0

[Guido van Rossum]

Guido van Rossum  added the comment:

We never should have mentioned 4.0 as the target date to make this the
default (and only) behavior -- who knows whether there will ever even be a
Python 4.0? Even 3.10 might be on the early side (assuming we'll switch to
a year-long release cycle per PEP 602 -- we will then make deprecations in
general take two release cycles).

I do agree that we should start the process of deprecating the
non-__future__ behavior here in 3.9. I know of one project with a private
fork of Python (for other reasons) that has made this default.

--

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue38605] [typing] PEP 563: Postponed evaluation of annotations: enable it by default before Python 4.0

[Eric V. Smith]

Change by Eric V. Smith :


--
nosy: +eric.smith

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue38605] [typing] PEP 563: Postponed evaluation of annotations: enable it by default before Python 4.0

[Ivan Levkivskyi]

Ivan Levkivskyi  added the comment:

IMO 3.10 would be better, since 3.9 would be too soon (it would be like a 
schedule for a normal deprecation).

Also if we are really doing this, I think it is better to announce this soon.

Also we should try to fix relevant issues related to string annotations (in 
typing and dataclasses), like https://github.com/python/typing/issues/508, 
https://github.com/python/typing/issues/574, 
https://bugs.python.org/issue37838, https://bugs.python.org/issue34776 and 
https://bugs.python.org/issue37948.

--
nosy: +gvanrossum

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue38605] [typing] PEP 563: Postponed evaluation of annotations: enable it by default before Python 4.0

[Karthikeyan Singaravelan]

Change by Karthikeyan Singaravelan :


--
nosy: +levkivskyi

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue38605] [typing] PEP 563: Postponed evaluation of annotations: enable it by default before Python 4.0

[STINNER Victor]

New submission from STINNER Victor :

The PEP 563: Postponed evaluation of annotations was introduced an opt-in 
feature using "from __future__ import annotations". It is scheduled to become 
the default in Python 4.0.

I would prefer to limit the number of incompatible changes in Python 4.0: it 
should just a "regular" release, with a regular number of incompatible changes. 
The version number change is going to cause enough troubles...

Would it be possible possible to enable postponed evaluation of annotations 
either before or after Python 4.0? For example, can we imagine to enable it by 
default in Python 3.9? If not, what about Python 3.10?

See also the PEP 608 (Coordinated Python release) and bpo-38604 (Schedule 
Py_UNICODE API removal).

--
components: Library (Lib)
messages: 355476
nosy: lukasz.langa, vstinner
priority: normal
severity: normal
status: open
title: [typing] PEP 563: Postponed evaluation of annotations: enable it by 
default before Python 4.0
versions: Python 3.9

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com