PSF. Nothing personal, of course... On October 5, 2015 3:01:11 PM CDT, Guido van Rossum <guido@python.org> wrote:

"They"?

On Mon, Oct 5, 2015 at 12:57 PM, Ryan Gonzalez <rymg19@gmail.com> wrote:

...

There is one reason I would be really freaking mad if they deprecated other uses of annotations:

https://pypi.python.org/pypi/plac

On October 5, 2015 1:55:37 PM CDT, Steve Wedig <stevewedig@gmail.com> wrote:

...

Congratulations on the release of 3.5 and Pep 484. I've used Python professionally for 10 years and I believe type hints will make it easier to work with large codebases evolving over time. My only concern about Pep 484 is the discussion of whether or not to deprecate arbitrary function annotations. https://www.python.org/dev/peps/pep-0484/

I would like to request that arbitrary function annotations are not deprecated for three reasons: 1. Backwards Compatibility 2. Type Experimentation 3. Embedded Languages

1. Backwards Compatibility After reading Pep 3107 my team has made significant use of non-standard annotations. It would be a serious burden to be forced to port our annotations back to decorators. This would also make our codebase considerably less readable because function annotations are much more readable than input/output annotations relegated to decorators. https://www.python.org/dev/peps/pep-3107/

2. Type Experimentation Arbitrary function annotations allow developers to experiment with potential type system improvements in real projects. Ideas can be validated before officially adding them to the language. This seems like an advantage that should be preserved. After all, Pep 484 says it was strongly inspired by MyPy, an existing project. http://mypy-lang.org/

3. Embedded Languages Python's flexibility makes it an amazing language to embed other languages in. In this regard, Python 3's addition of arbitrary function annotations and class decorators complements Python 2's dynamic typing, function decorators, reflection, metaclasses, properties, magic methods, generators, and keyword arguments. Arbitrary function annotations are a crucial part of this toolkit, and this feature is not available in most other languages. For anyone interested in the utility and mechanics of embedded languages, I'd recommend Martin Fowler's book: Domain Specific Languages.

...

...

So I agree with the course of action mentioned in Pep 484 that

avoids

...

runtime deprecation of arbitrary function annotation: "Another

http://www.amazon.com/Domain-Specific-Languages-Addison-Wesley-Signature-Ser... possible

...

...

outcome would be that type hints will eventually become the default meaning for annotations, but that there will always remain an option to disable them." I would only add that there should be a way to disable type checking for an entire directory (recursively). This would be useful for codebases that have not been ported to standard annotations yet, and for codebases that will not be ported for the reasons listed above.

Thanks for your consideration.

Best, Steve

------------------------------------------------------------------------

...

_______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe:

https://mail.python.org/mailman/options/python-dev/rymg19%40gmail.com

-- Sent from my Nexus 5 with K-9 Mail. Please excuse my brevity. _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/guido%40python.org

-- --Guido van Rossum (python.org/~guido)

-- Sent from my Nexus 5 with K-9 Mail. Please excuse my brevity.

Brett and Alexander, I am concerned about deprecation of arbitrary function annotations because Pep 484 suggests that two paths are under consideration. Here is the relevant section: " We do hope that type hints will eventually become the sole use for annotations, but this will require additional discussion and a deprecation period after the initial roll-out of the typing module with Python 3.5. The current PEP will have provisional status (see PEP 411 ) until Python 3.6 is released. The fastest conceivable scheme would introduce silent deprecation of non-type-hint annotations in 3.6, full deprecation in 3.7, and declare type hints as the only allowed use of annotations in Python 3.8. This should give authors of packages that use annotations plenty of time to devise another approach, even if type hints become an overnight success. Another possible outcome would be that type hints will eventually become the default meaning for annotations, but that there will always remain an option to disable them. For this purpose the current proposal defines a decorator @no_type_check which disables the default interpretation of annotations as type hints in a given class or function. It also defines a meta-decorator @no_type_check_decorator which can be used to decorate a decorator (!), causing annotations in any function or class decorated with the latter to be ignored by the type checker. " I am advocating against paragraph 1 (a deprecation path) and for the course of action stated in paragraph 2 :) On Mon, Oct 5, 2015 at 1:23 PM, Guido van Rossum <guido@python.org> wrote:

Maybe I should clarify how the process of changing the language works.

The PSF doesn't enter into it -- they manage the infrastructure (e.g. mailing lists, Hg repo, tracker, python.org) but they don't have anything to do with deciding how or when the language changes.

Language changes are done *here* by *us* all. Anyone can write a PEP and it will be discussed here (but first in python-ideas of course).

I'm sorry you don't feel more included, but I really don't like the idea of "us vs. them" in this list. We're all working together to make Python the best language it can be.

--Guido

On Mon, Oct 5, 2015 at 1:18 PM, Ryan Gonzalez <rymg19@gmail.com> wrote:

...

PSF. Nothing personal, of course...

On October 5, 2015 3:01:11 PM CDT, Guido van Rossum <guido@python.org> wrote:

...

"They"?

On Mon, Oct 5, 2015 at 12:57 PM, Ryan Gonzalez <rymg19@gmail.com> wrote:

...

There is one reason I would be really freaking mad if they deprecated other uses of annotations:

https://pypi.python.org/pypi/plac

On October 5, 2015 1:55:37 PM CDT, Steve Wedig <stevewedig@gmail.com> wrote:

...

Congratulations on the release of 3.5 and Pep 484. I've used Python professionally for 10 years and I believe type hints will make it easier to work with large codebases evolving over time. My only concern about Pep 484 is the discussion of whether or not to deprecate arbitrary function annotations. https://www.python.org/dev/peps/pep-0484/

I would like to request that arbitrary function annotations are not deprecated for three reasons: 1. Backwards Compatibility 2. Type Experimentation 3. Embedded Languages

1. Backwards Compatibility After reading Pep 3107 my team has made significant use of non-standard annotations. It would be a serious burden to be forced to port our annotations back to decorators. This would also make our codebase considerably less readable because function annotations are much more readable than input/output annotations relegated to decorators. https://www.python.org/dev/peps/pep-3107/

2. Type Experimentation Arbitrary function annotations allow developers to experiment with potential type system improvements in real projects. Ideas can be validated before officially adding them to the language. This seems like an advantage that should be preserved. After all, Pep 484 says it was strongly inspired by MyPy, an existing project. http://mypy-lang.org/

3. Embedded Languages Python's flexibility makes it an amazing language to embed other languages in. In this regard, Python 3's addition of arbitrary function annotations and class decorators complements Python 2's dynamic typing, function decorators, reflection, metaclasses, properties, magic methods, generators, and keyword arguments. Arbitrary function annotations are a crucial part of this toolkit, and this feature is not available in most other languages. For anyone interested in the utility and mechanics of embedded languages, I'd recommend Martin Fowler's book: Domain Specific Languages.

http://www.amazon.com/Domain-Specific-Languages-Addison-Wesley-Signature-Ser...

...

So I agree with the course of action mentioned in Pep 484 that avoids runtime deprecation of arbitrary function annotation: "Another possible outcome would be that type hints will eventually become the default meaning for annotations, but that there will always remain an option to disable them." I would only add that there should be a way to disable type checking for an entire directory (recursively). This would be useful for codebases that have not been ported to standard annotations yet, and for codebases that will not be ported for the reasons listed above.

Thanks for your consideration.

Best, Steve

...

------------------------------------------------------------------------

_______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/rymg19%40gmail.com

-- Sent from my Nexus 5 with K-9 Mail. Please excuse my brevity. _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/guido%40python.org

-- Sent from my Nexus 5 with K-9 Mail. Please excuse my brevity.

-- --Guido van Rossum (python.org/~guido)

-- Steve Wedig stevewedig.com linkedin.com/in/wedig <http://www.linkedin.com/in/wedig>

On Mon, 5 Oct 2015 at 13:55 Steve Wedig <stevewedig@gmail.com> wrote:

Brett and Alexander,

I am concerned about deprecation of arbitrary function annotations because Pep 484 suggests that two paths are under consideration. Here is the relevant section:

" We do hope that type hints will eventually become the sole use for annotations, but this will require additional discussion and a deprecation period after the initial roll-out of the typing module with Python 3.5. The current PEP will have provisional status (see PEP 411 ) until Python 3.6 is released. The fastest conceivable scheme would introduce silent deprecation of non-type-hint annotations in 3.6, full deprecation in 3.7, and declare type hints as the only allowed use of annotations in Python 3.8. This should give authors of packages that use annotations plenty of time to devise another approach, even if type hints become an overnight success.

Another possible outcome would be that type hints will eventually become the default meaning for annotations, but that there will always remain an option to disable them. For this purpose the current proposal defines a decorator @no_type_check which disables the default interpretation of annotations as type hints in a given class or function. It also defines a meta-decorator @no_type_check_decorator which can be used to decorate a decorator (!), causing annotations in any function or class decorated with the latter to be ignored by the type checker. "

I am advocating against paragraph 1 (a deprecation path) and for the course of action stated in paragraph 2 :)

Fair enough, but since Python 3.5 is so new we have yet to gather any feedback on the entire concept of type hints, let alone whether their use is so broad and liked that we will consider dropping the decorators in `typing` which mark alternative uses and define "function annotations" as "type annotations" for everything. So consider your view noted, but realize that the discussion of the uptake of type hints has not started yet as it's premature to do so. If you want to make sure to participate if/when the discussion of dropping support for alternative uses of function annocations then consider staying subscribed to python-dev to notice when that happens (but I suspect it will be a while). -Brett

On Mon, Oct 5, 2015 at 1:23 PM, Guido van Rossum <guido@python.org> wrote:

...

Maybe I should clarify how the process of changing the language works.

The PSF doesn't enter into it -- they manage the infrastructure (e.g. mailing lists, Hg repo, tracker, python.org) but they don't have anything to do with deciding how or when the language changes.

Language changes are done *here* by *us* all. Anyone can write a PEP and it will be discussed here (but first in python-ideas of course).

I'm sorry you don't feel more included, but I really don't like the idea of "us vs. them" in this list. We're all working together to make Python the best language it can be.

--Guido

On Mon, Oct 5, 2015 at 1:18 PM, Ryan Gonzalez <rymg19@gmail.com> wrote:

...

PSF. Nothing personal, of course...

On October 5, 2015 3:01:11 PM CDT, Guido van Rossum <guido@python.org> wrote:

...

"They"?

On Mon, Oct 5, 2015 at 12:57 PM, Ryan Gonzalez <rymg19@gmail.com> wrote:

...

There is one reason I would be really freaking mad if they deprecated other uses of annotations:

https://pypi.python.org/pypi/plac

On October 5, 2015 1:55:37 PM CDT, Steve Wedig <stevewedig@gmail.com> wrote:

...

Congratulations on the release of 3.5 and Pep 484. I've used Python professionally for 10 years and I believe type hints will make it easier to work with large codebases evolving over time. My only concern about Pep 484 is the discussion of whether or not to deprecate arbitrary function annotations. https://www.python.org/dev/peps/pep-0484/

I would like to request that arbitrary function annotations are not deprecated for three reasons: 1. Backwards Compatibility 2. Type Experimentation 3. Embedded Languages

1. Backwards Compatibility After reading Pep 3107 my team has made significant use of non-standard annotations. It would be a serious burden to be forced to port our annotations back to decorators. This would also make our codebase considerably less readable because function annotations are much more readable than input/output annotations relegated to decorators. https://www.python.org/dev/peps/pep-3107/

2. Type Experimentation Arbitrary function annotations allow developers to experiment with potential type system improvements in real projects. Ideas can be validated before officially adding them to the language. This seems like an advantage that should be preserved. After all, Pep 484 says it was strongly inspired by MyPy, an existing project. http://mypy-lang.org/

3. Embedded Languages Python's flexibility makes it an amazing language to embed other languages in. In this regard, Python 3's addition of arbitrary function annotations and class decorators complements Python 2's dynamic typing, function decorators, reflection, metaclasses, properties, magic methods, generators, and keyword arguments. Arbitrary function annotations are a crucial part of this toolkit, and this feature is not available in most other languages. For anyone interested in the utility and mechanics of embedded languages, I'd recommend Martin Fowler's book: Domain Specific Languages.

http://www.amazon.com/Domain-Specific-Languages-Addison-Wesley-Signature-Ser...

...

So I agree with the course of action mentioned in Pep 484 that avoids runtime deprecation of arbitrary function annotation: "Another

possible

...

outcome would be that type hints will eventually become the default meaning for annotations, but that there will always remain an option to disable them." I would only add that there should be a way to disable type checking for an entire directory (recursively). This would be useful for codebases that have not been ported to standard annotations yet, and for codebases that will not be ported for the reasons listed above.

Thanks for your consideration.

Best, Steve

...

------------------------------------------------------------------------

_______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/rymg19%40gmail.com

-- Sent from my Nexus 5 with K-9 Mail. Please excuse my brevity. _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/guido%40python.org

-- Sent from my Nexus 5 with K-9 Mail. Please excuse my brevity.

-- --Guido van Rossum (python.org/~guido)

-- Steve Wedig stevewedig.com linkedin.com/in/wedig <http://www.linkedin.com/in/wedig>

_______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/brett%40python.org

Function annotations for uses other than types are not deprecated, just discouraged if they don't have an appropriate decorator: https://docs.python.org/3/library/typing.html#typing.no_type_check . There is even a decorator for decorators since most uses previous to type hints utilized some form of a decorator: https://docs.python.org/3/library/typing.html#typing.no_type_check_decorator . And as a last resort you simply don't use your Python code with anything that assumes type hints. On Mon, 5 Oct 2015 at 12:57 Ryan Gonzalez <rymg19@gmail.com> wrote:

There is one reason I would be really freaking mad if they deprecated other uses of annotations:

https://pypi.python.org/pypi/plac

On October 5, 2015 1:55:37 PM CDT, Steve Wedig <stevewedig@gmail.com> wrote:

...

Congratulations on the release of 3.5 and Pep 484. I've used Python professionally for 10 years and I believe type hints will make it easier to work with large codebases evolving over time. My only concern about Pep 484 is the discussion of whether or not to deprecate arbitrary function annotations. https://www.python.org/dev/peps/pep-0484/

I would like to request that arbitrary function annotations are not deprecated for three reasons: 1. Backwards Compatibility 2. Type Experimentation 3. Embedded Languages

1. Backwards Compatibility After reading Pep 3107 my team has made significant use of non-standard annotations. It would be a serious burden to be forced to port our annotations back to decorators. This would also make our codebase considerably less readable because function annotations are much more readable than input/output annotations relegated to decorators. https://www.python.org/dev/peps/pep-3107/

2. Type Experimentation Arbitrary function annotations allow developers to experiment with potential type system improvements in real projects. Ideas can be validated before officially adding them to the language. This seems like an advantage that should be preserved. After all, Pep 484 says it was strongly inspired by MyPy, an existing project. http://mypy-lang.org/

3. Embedded Languages Python's flexibility makes it an amazing language to embed other languages in. In this regard, Python 3's addition of arbitrary function annotations and class decorators complements Python 2's dynamic typing, function decorators, reflection, metaclasses, properties, magic methods, generators, and keyword arguments. Arbitrary function annotations are a crucial part of this toolkit, and this feature is not available in most other languages. For anyone interested in the utility and mechanics of embedded languages, I'd recommend Martin Fowler's book: Domain Specific Languages.

http://www.amazon.com/Domain-Specific-Languages-Addison-Wesley-Signature-Ser...

...

So I agree with the course of action mentioned in Pep 484 that avoids runtime deprecation of arbitrary function annotation: "Another possible outcome would be that type hints will eventually become the default meaning for annotations, but that there will always remain an option to disable them." I would only add that there should be a way to disable type checking for an entire directory (recursively). This would be useful for codebases that have not been ported to standard annotations yet, and for codebases that will not be ported for the reasons listed above.

Thanks for your consideration.

Best, Steve

------------------------------------------------------------------------

_______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/rymg19%40gmail.com

-- Sent from my Nexus 5 with K-9 Mail. Please excuse my brevity. _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/brett%40python.org