Remove asyncore, asynchat and smtpd modules
Hi,
The asyncore module is a very old module of the Python stdlib for asynchronous programming, usually to handle network sockets concurrently. It's a common event loop, but its design has many flaws.
The asyncio module was added to Python 3.4 with a well designed architecture. Twisted developers, who have like 10 to 20 years of experience in asynchronous programming, helped to design the asyncio API. By design, asyncio doesn't have flaws which would be really hard to fix in asyncore and asynchat.
It was decided to start deprecating the asyncore, asynchat and smtpd modules in Python 3.6 released in 2016, 5 years ago. Python 3.10 emits DeprecationWarning. asynchat and smtpd are implemented with asyncore. Open issues in asyncore, asynchat and smtpd have been closed as "wont fix" because these modules are deprecated. These modules are basically no longer maintained.
I propose to remove asyncore, aynchat and smtpd in Python 3.11 to reduce the Python maintenance burden, while asyncio remains available in stdlib and is maintained:
* asyncore and asynchat can be replaced with asyncio * smtpd can be replaced with aiosmtpd which is based on asyncio: https://aiosmtpd.readthedocs.io/
If someone wants to continue using asyncore, asynchat or smtpd, it's trivial to copy Python 3.10 asyncore.py, asynchat.py and smtpd.py to their project, and maintain these files there. Someone is also free to continue maintaining these modules as third-party projects on PyPI.
The removal is discussed at: https://bugs.python.org/issue28533
I wrote a PR to remove the 3 modules: https://github.com/python/cpython/pull/29521
... in short, the intent is to move the asyncore, asynchat and smtpd maintenance outside the Pyhon project ;-) (if anyone still use them)
Victor
Yes please. Long overdue.
On Thu, Nov 11, 2021 at 4:38 AM Victor Stinner vstinner@python.org wrote:
Hi,
The asyncore module is a very old module of the Python stdlib for asynchronous programming, usually to handle network sockets concurrently. It's a common event loop, but its design has many flaws.
The asyncio module was added to Python 3.4 with a well designed architecture. Twisted developers, who have like 10 to 20 years of experience in asynchronous programming, helped to design the asyncio API. By design, asyncio doesn't have flaws which would be really hard to fix in asyncore and asynchat.
It was decided to start deprecating the asyncore, asynchat and smtpd modules in Python 3.6 released in 2016, 5 years ago. Python 3.10 emits DeprecationWarning. asynchat and smtpd are implemented with asyncore. Open issues in asyncore, asynchat and smtpd have been closed as "wont fix" because these modules are deprecated. These modules are basically no longer maintained.
I propose to remove asyncore, aynchat and smtpd in Python 3.11 to reduce the Python maintenance burden, while asyncio remains available in stdlib and is maintained:
- asyncore and asynchat can be replaced with asyncio
- smtpd can be replaced with aiosmtpd which is based on asyncio:
https://aiosmtpd.readthedocs.io/
If someone wants to continue using asyncore, asynchat or smtpd, it's trivial to copy Python 3.10 asyncore.py, asynchat.py and smtpd.py to their project, and maintain these files there. Someone is also free to continue maintaining these modules as third-party projects on PyPI.
The removal is discussed at: https://bugs.python.org/issue28533
I wrote a PR to remove the 3 modules: https://github.com/python/cpython/pull/29521
... in short, the intent is to move the asyncore, asynchat and smtpd maintenance outside the Pyhon project ;-) (if anyone still use them)
Victor
Night gathers, and now my watch begins. It shall not end until my death. _______________________________________________ Python-Dev mailing list -- python-dev@python.org To unsubscribe send an email to python-dev-leave@python.org https://mail.python.org/mailman3/lists/python-dev.python.org/ Message archived at https://mail.python.org/archives/list/python-dev@python.org/message/LZOOLX5E... Code of Conduct: http://python.org/psf/codeofconduct/
On 11. 11. 21 13:31, Victor Stinner wrote:
Hi,
The asyncore module is a very old module of the Python stdlib for asynchronous programming, usually to handle network sockets concurrently. It's a common event loop, but its design has many flaws.
The asyncio module was added to Python 3.4 with a well designed architecture. Twisted developers, who have like 10 to 20 years of experience in asynchronous programming, helped to design the asyncio API. By design, asyncio doesn't have flaws which would be really hard to fix in asyncore and asynchat.
It was decided to start deprecating the asyncore, asynchat and smtpd modules in Python 3.6 released in 2016, 5 years ago. Python 3.10 emits DeprecationWarning.
Wait, only Python 3.10? According to the policy, the warning should be there for *at least* two releases. (That's a minimum, for removing entire modules it might make sense to give people even more time.)
asynchat and smtpd are implemented with asyncore. Open issues in asyncore, asynchat and smtpd have been closed as "wont fix" because these modules are deprecated. These modules are basically no longer maintained.
I propose to remove asyncore, aynchat and smtpd in Python 3.11 to reduce the Python maintenance burden, while asyncio remains available in stdlib and is maintained:
- asyncore and asynchat can be replaced with asyncio
- smtpd can be replaced with aiosmtpd which is based on asyncio:
https://aiosmtpd.readthedocs.io/
If someone wants to continue using asyncore, asynchat or smtpd, it's trivial to copy Python 3.10 asyncore.py, asynchat.py and smtpd.py to their project, and maintain these files there. Someone is also free to continue maintaining these modules as third-party projects on PyPI.
The removal is discussed at: https://bugs.python.org/issue28533
I wrote a PR to remove the 3 modules: https://github.com/python/cpython/pull/29521
... in short, the intent is to move the asyncore, asynchat and smtpd maintenance outside the Pyhon project ;-) (if anyone still use them)
Victor
It was decided to start deprecating the asyncore, asynchat and smtpd modules in Python 3.6 released in 2016, 5 years ago. Python 3.10 emits DeprecationWarning.
Wait, only Python 3.10? According to the policy, the warning should be there for *at least* two releases. (That's a minimum, for removing entire modules it might make sense to give people even more time.)
The PEP 387 says "Similarly a feature cannot be removed without notice between any two consecutive releases."
It is the case here. The 3 modules are marked as deprecated for 4 releases in the documentation: Python 3.6, 3.7, 3.9 and 3.10. Example: https://docs.python.org/3.6/library/asyncore.html
Victor
On Fri, Nov 12, 2021 at 4:16 AM Victor Stinner vstinner@python.org wrote:
It was decided to start deprecating the asyncore, asynchat and smtpd modules in Python 3.6 released in 2016, 5 years ago. Python 3.10 emits DeprecationWarning.
Wait, only Python 3.10? According to the policy, the warning should be there for *at least* two releases. (That's a minimum, for removing entire modules it might make sense to give people even more time.)
The PEP 387 says "Similarly a feature cannot be removed without notice between any two consecutive releases."
It is the case here. The 3 modules are marked as deprecated for 4 releases in the documentation: Python 3.6, 3.7, 3.9 and 3.10. Example: https://docs.python.org/3.6/library/asyncore.html
But have they been raising exceptions for two releases?
On Tue, Nov 16, 2021 at 1:15 AM Brett Cannon brett@python.org wrote:
But have they been raising exceptions for two releases?
As I wrote previously, the DeprecationWarning warning is only emitted at runtime since Python 3.10.
Since my PR got 5 approvals, I just merged it: https://github.com/python/cpython/pull/29521
The asyncore, asynchat and smtpd modules are now removed in Python 3.11. You should now use asyncio and aiosmtpd instead.
Note: the binhex module has also been removed in Python 3.11. It emitted a DeprecationWarning in Python 3.9 and 3.10.
Victor
On 16. 11. 21 1:36, Victor Stinner wrote:
As I wrote previously, the DeprecationWarning warning is only emitted at runtime since Python 3.10.
Since my PR got 5 approvals, I just merged it: https://github.com/python/cpython/pull/29521
No mater the number of approvals, this removal does not follow the policy.
On 12. 11. 21 13:09, Victor Stinner wrote:
It was decided to start deprecating the asyncore, asynchat and smtpd modules in Python 3.6 released in 2016, 5 years ago. Python 3.10 emits DeprecationWarning.
Wait, only Python 3.10? According to the policy, the warning should be there for *at least* two releases. (That's a minimum, for removing entire modules it might make sense to give people even more time.)
The PEP 387 says "Similarly a feature cannot be removed without notice between any two consecutive releases."
It is the case here. The 3 modules are marked as deprecated for 4 releases in the documentation: Python 3.6, 3.7, 3.9 and 3.10. Example: https://docs.python.org/3.6/library/asyncore.html
PEP 387 also contains a detailed process for making incompatible changes, which calls for warnings to appear in at least two releases.
Do you think the process section can be ignored? We should remove it from the PEP if that's the case.
On Tue, Nov 16, 2021 at 3:05 AM Petr Viktorin encukou@gmail.com wrote:
On 12. 11. 21 13:09, Victor Stinner wrote:
It was decided to start deprecating the asyncore, asynchat and smtpd modules in Python 3.6 released in 2016, 5 years ago. Python 3.10 emits DeprecationWarning.
Wait, only Python 3.10? According to the policy, the warning should be there for *at least* two releases. (That's a minimum, for removing entire modules it might make sense to give people even more time.)
The PEP 387 says "Similarly a feature cannot be removed without notice between any two consecutive releases."
It is the case here. The 3 modules are marked as deprecated for 4 releases in the documentation: Python 3.6, 3.7, 3.9 and 3.10. Example: https://docs.python.org/3.6/library/asyncore.html
PEP 387 also contains a detailed process for making incompatible changes, which calls for warnings to appear in at least two releases.
Do you think the process section can be ignored? We should remove it from the PEP if that's the case.
I don't think it should be ignored and the modules got yanked prematurely. A request can be made to the SC, though, to expedite the removal with only one release raising an exception.
I created https://github.com/python/steering-council/issues/86 to ask for a SC exception.
Victor
On Tue, Nov 16, 2021 at 8:11 PM Brett Cannon brett@python.org wrote:
On Tue, Nov 16, 2021 at 3:05 AM Petr Viktorin encukou@gmail.com wrote:
On 12. 11. 21 13:09, Victor Stinner wrote:
It was decided to start deprecating the asyncore, asynchat and smtpd modules in Python 3.6 released in 2016, 5 years ago. Python 3.10 emits DeprecationWarning.
Wait, only Python 3.10? According to the policy, the warning should be there for *at least* two releases. (That's a minimum, for removing entire modules it might make sense to give people even more time.)
The PEP 387 says "Similarly a feature cannot be removed without notice between any two consecutive releases."
It is the case here. The 3 modules are marked as deprecated for 4 releases in the documentation: Python 3.6, 3.7, 3.9 and 3.10. Example: https://docs.python.org/3.6/library/asyncore.html
PEP 387 also contains a detailed process for making incompatible changes, which calls for warnings to appear in at least two releases.
Do you think the process section can be ignored? We should remove it from the PEP if that's the case.
I don't think it should be ignored and the modules got yanked prematurely. A request can be made to the SC, though, to expedite the removal with only one release raising an exception.
I think it would be fine to wait just one release, until 3.12. Makes no substantial maintenance difference and maybe easier for users with more advanced notice, especially for module removal.
I also wonder if maybe we should scale delay between dep -> removal based on maintenance burden estimate, rather than 2 versions for all. Module removal certainly takes more effort to adjust in code vs simple function name change with 1:1 replacement.
Speaking as the author of the doc pages, I think I can safely say that anyone who was smart enough to use asyncore/asychat back in the day (I used it in "Python Web Programming") is almost certainly smart enough to have migrated away from them long ago. They were an interesting approach to asynchronous networking, but I think it's safe to say that world has moved on in 20 years.
Kind regards, Steve
On Wed, Nov 17, 2021 at 6:13 AM Kyle Stanley aeros167@gmail.com wrote:
I think it would be fine to wait just one release, until 3.12. Makes no substantial maintenance difference and maybe easier for users with more advanced notice, especially for module removal.
I also wonder if maybe we should scale delay between dep -> removal based on maintenance burden estimate, rather than 2 versions for all. Module removal certainly takes more effort to adjust in code vs simple function name change with 1:1 replacement.
-- --Kyle R. Stanley, Python Core Developer (what is a core dev? https://devguide.python.org/coredev/) *Pronouns: they/them **(why is my pronoun here?* http://feministing.com/2015/02/03/how-using-they-as-a-singular-pronoun-can-change-the-world/ )
Python-Dev mailing list -- python-dev@python.org To unsubscribe send an email to python-dev-leave@python.org https://mail.python.org/mailman3/lists/python-dev.python.org/ Message archived at https://mail.python.org/archives/list/python-dev@python.org/message/F52UKISV... Code of Conduct: http://python.org/psf/codeofconduct/
participants (7)
-
Brett Cannon -
Guido van Rossum -
Kyle Stanley -
Miro Hrončok -
Petr Viktorin -
Steve Holden -
Victor Stinner