On Wed, 17 Jun 2020 at 10:44, artem6191 wrote:

So yeah, we can "if <expression>: return", but why not?

That's the wrong question. The correct question is "why is this needed, and is the need sufficiently pressing to justify the change to the language?" You're talking about allowing "return EXPR if CONDITION" as an exact equivalent of "if CONDITION: return EXPR". There isn't even a benefit of "it saves a line of code", so it's very hard to see a justification. Paul

On 6/17/20 5:42 AM, artem6191 wrote:

So yeah, we can "if <expression>: return", but why not?

From Pep 20 (The Zen) There should be one-- and preferably only one --obvious way to do it. We don't add a second way to do something just because we can, there needs to be some clear need that the existing way doesn't handle. -- Richard Damon

To read* Em qui, 18 de jun de 2020 09:30, Daniel. escreveu:

I love the do_stuff if cond syntax in Ruby and in perl. It's very natural to real, much more to follow than if cond: do_stuff

But still I don't think that it is enough to demand a language change.

Something near this is to have a default of none for

A if B else None

So we can ommit the else None part, but this goes against the explicit is better than implicit

Em qua, 17 de jun de 2020 07:42, Paul Moore escreveu:

...

On Wed, 17 Jun 2020 at 10:44, artem6191 wrote:

...

So yeah, we can "if <expression>: return", but why not?

That's the wrong question. The correct question is "why is this needed, and is the need sufficiently pressing to justify the change to the language?"

You're talking about allowing "return EXPR if CONDITION" as an exact equivalent of "if CONDITION: return EXPR". There isn't even a benefit of "it saves a line of code", so it's very hard to see a justification.

Paul _______________________________________________ Python-ideas mailing list -- python-ideas@python.org To unsubscribe send an email to python-ideas-leave@python.org https://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://mail.python.org/archives/list/python-ideas@python.org/message/PHB2VW... Code of Conduct: http://python.org/psf/codeofconduct/

This is very personal preference I don't feel it pythonic but... Ruby make return keywork optional so is very idiomatic (in Ruby) to have multiple onliner early return with this kind of guards at beginning of methods and a "main" case below For me this is just eye preference, we have eyes trained to extract what is important when reading code. There is no absolute more readable that works for everyone IMHO return if cond is more scannable than if cond: return Which need eye to scroll to next line Here is an example of the use case that I'm talking about def foo(): if a: return if B: return if C: return do_stuff() Vs def foo(): return if a return if B return if C do_stuff The second is much more compact And if A: return Well, I'm strongly against these non-indented blocks in python Em qui, 18 de jun de 2020 13:36, Barry Scott escreveu:

On 18 Jun 2020, at 13:30, Daniel. wrote:

I love the do_stuff if cond syntax in Ruby and in perl. It's very natural to real, much more to follow than if cond: do_stuff

I on the other hand hate that syntax and find it harder to read.

Why put the code out of sequence?

if read_this_1st: read_this_2nd()

vs. this that I think of as out of sequence order

read_this_2nd() if not read_this_1st

Barry

But still I don't think that it is enough to demand a language change.

Something near this is to have a default of none for

A if B else None

So we can ommit the else None part, but this goes against the explicit is better than implicit

Em qua, 17 de jun de 2020 07:42, Paul Moore escreveu:

...

On Wed, 17 Jun 2020 at 10:44, artem6191 wrote:

...

So yeah, we can "if <expression>: return", but why not?

That's the wrong question. The correct question is "why is this needed, and is the need sufficiently pressing to justify the change to the language?"

You're talking about allowing "return EXPR if CONDITION" as an exact equivalent of "if CONDITION: return EXPR". There isn't even a benefit of "it saves a line of code", so it's very hard to see a justification.

Paul _______________________________________________ Python-ideas mailing list -- python-ideas@python.org To unsubscribe send an email to python-ideas-leave@python.org https://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://mail.python.org/archives/list/python-ideas@python.org/message/PHB2VW... Code of Conduct: http://python.org/psf/codeofconduct/

_______________________________________________ Python-ideas mailing list -- python-ideas@python.org To unsubscribe send an email to python-ideas-leave@python.org https://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://mail.python.org/archives/list/python-ideas@python.org/message/WEK6CT... Code of Conduct: http://python.org/psf/codeofconduct/

it is not worth changing Python over. I agreed here, is doesn't make that difference Em qui, 18 de jun de 2020 14:25, Christopher Barker escreveu:

On Thu, Jun 18, 2020 at 10:00 AM Daniel. wrote:

...

def foo(): if a: return if B: return if C: return

do_stuff()

Vs

def foo(): return if a return if B return if C do_stuff

The second is much more compact

is compact good ?!?

...

if A: return

Well, I'm strongly against these non-indented blocks in python

But why? you nseem to theink the more compact Ruby version is better, so why not the more compact Python version -- the only difference is a colon, and the order:

def foo(): if a: return if B: return if C: return

which is equally compact, and puts the "meat" of the code up front, which feels more clear and obvious to me.

I do use this form myself, in just this situation, where there are multiple cases, and it is compact enough that the return doesn't get lost. That is, I would not do:

if ( A and B) or (this > that) and (something in everything): return

in that case, the return gets lost out at the end -- even if you don't go beyond 72 chars.

anyway, even if it's a slight be more readable to some, it is not worth changing Python over.

-CHB

...

Em qui, 18 de jun de 2020 13:36, Barry Scott escreveu:

...

On 18 Jun 2020, at 13:30, Daniel. wrote:

I love the do_stuff if cond syntax in Ruby and in perl. It's very natural to real, much more to follow than if cond: do_stuff

I on the other hand hate that syntax and find it harder to read.

Why put the code out of sequence?

if read_this_1st: read_this_2nd()

vs. this that I think of as out of sequence order

read_this_2nd() if not read_this_1st

Barry

But still I don't think that it is enough to demand a language change.

Something near this is to have a default of none for

A if B else None

So we can ommit the else None part, but this goes against the explicit is better than implicit

Em qua, 17 de jun de 2020 07:42, Paul Moore escreveu:

...

On Wed, 17 Jun 2020 at 10:44, artem6191 wrote:

...

So yeah, we can "if <expression>: return", but why not?

That's the wrong question. The correct question is "why is this needed, and is the need sufficiently pressing to justify the change to the language?"

You're talking about allowing "return EXPR if CONDITION" as an exact equivalent of "if CONDITION: return EXPR". There isn't even a benefit of "it saves a line of code", so it's very hard to see a justification.

Paul _______________________________________________ Python-ideas mailing list -- python-ideas@python.org To unsubscribe send an email to python-ideas-leave@python.org https://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://mail.python.org/archives/list/python-ideas@python.org/message/PHB2VW... Code of Conduct: http://python.org/psf/codeofconduct/

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_______________________________________________

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-- Christopher Barker, PhD

Python Language Consulting - Teaching - Scientific Software Development - Desktop GUI and Web Development - wxPython, numpy, scipy, Cython

You can already do compact conditional returns with the current syntax: def foo(a, b): return (a != b or None) and a * b or even: foo = (lambda a, b: (a != b or None) and a * b) both return: foo(2, 5) # 10 foo(1, 1) # None ... but clarity would be better. On Fri, Jun 19, 2020 at 4:20 AM Serhiy Storchaka wrote:

18.06.20 15:30, Daniel. пише:

...

I love the do_stuff if cond syntax in Ruby and in perl. It's very natural to real, much more to follow than if cond: do_stuff

But still I don't think that it is enough to demand a language change.

Something near this is to have a default of none for

A if B else None

So we can ommit the else None part, but this goes against the explicit is better than implicit

Only around 10% of "if" expressions have "else None" part. It is not enough to justify a new syntax (even if ignore other objections). _______________________________________________ Python-ideas mailing list -- python-ideas@python.org To unsubscribe send an email to python-ideas-leave@python.org https://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://mail.python.org/archives/list/python-ideas@python.org/message/5E6JG6... Code of Conduct: http://python.org/psf/codeofconduct/

On Sat, 20 Jun 2020 at 04:02, MRAB wrote:

On 2020-06-20 02:22, Robert DeLanghe wrote:

...

You can already do compact conditional returns with the current syntax:

def foo(a, b): return (a != b or None) and a * b

or even:

foo = (lambda a, b: (a != b or None) and a * b)

both return:

foo(2, 5) # 10 foo(1, 1) # None

... but clarity would be better.

That can be written more clearly:

def foo(a, b): return a * b if a != b else None

I find the non-compact version to be clearer: def foo(a, b): if a != b: return a*b return None

...

On Fri, Jun 19, 2020 at 4:20 AM Serhiy Storchaka mailto:storchaka@gmail.com> wrote:

18.06.20 15:30, Daniel. пише: > I love the do_stuff if cond syntax in Ruby and in perl. It's very > natural to real, much more to follow than if cond: do_stuff > > But still I don't think that it is enough to demand a language change. > > Something near this is to have a default of none for > > A if B else None > > So we can ommit the else None part, but this goes against the explicit > is better than implicit

Only around 10% of "if" expressions have "else None" part. It is not enough to justify a new syntax (even if ignore other objections).

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