Most of programming languages out there have switch-case statements. Python doesn't have support for switch-case statements though. switch-case statements can sometimes be nice and tidy and sometimes it may be a horrible nightmare. But that also applies to if-elif-else statements. It would be nice to have switch-case statements support in python. Suggested syntax :- ------------------- switch expr: case expr2: case expr3: statements default: statements How should it be implemented? ----------------------------------- First of all this will require a new syntax. Second I suggest for comparing the case expr with switch expr, compare the pointers instead of objects for better performance. Usually if the ladder is represented using if-elif-else logic then it would be lower performance because we'll end up comparing objects not pointers.
How is this differs from PEP 634 (https://docs.python.org/3.10/whatsnew/3.10.html#pep-634-structural-pattern-m... On 2021. 05. 04. 20:33, Shreyan Avigyan wrote:
Most of programming languages out there have switch-case statements. Python doesn't have support for switch-case statements though. switch-case statements can sometimes be nice and tidy and sometimes it may be a horrible nightmare. But that also applies to if-elif-else statements. It would be nice to have switch-case statements support in python.
Suggested syntax :- -------------------
switch expr: case expr2: case expr3: statements default: statements
How should it be implemented? -----------------------------------
First of all this will require a new syntax. Second I suggest for comparing the case expr with switch expr, compare the pointers instead of objects for better performance. Usually if the ladder is represented using if-elif-else logic then it would be lower performance because we'll end up comparing objects not pointers. _______________________________________________ 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/32SKTI... Code of Conduct: http://python.org/psf/codeofconduct/
Isn't PEP 643 for PEG grammar pattern matching? (I'm talking about switch statements in Python)
Isn't PEP 643 for PEG grammar pattern matching? (I'm talking about switch statements in Python)
I think you are referring to PEP 634, the one I linked to. I suggest you read it (and the other link I sent). I copy from PEP 636, marked as a sort of "tutorial" for PEP 634: ``` A match statement takes an expression and compares its value to successive patterns given as one or more case blocks. This is superficially similar to a switch statement in C, Java or JavaScript (and many other languages), but much more powerful. The simplest form compares a subject value against one or more literals: def http_error(status): match status: case 400: return "Bad request" case 404: return "Not found" case 418: return "I'm a teapot" case _: return "Something's wrong with the Internet" ``` - DLD
Ok. Now I'm able to understand. PEP 634 should have a reference to PEP 636 or else it's pretty hard to understand because the syntax section demonstrates PEG implementation of this.
I'm not sure if you're reading the right document, but PEP 634 refers to 636 in its second paragraph On Tue, 4 May 2021, 19:56 Shreyan Avigyan, <pythonshreyan09@gmail.com> wrote:
Ok. Now I'm able to understand. PEP 634 should have a reference to PEP 636 or else it's pretty hard to understand because the syntax section demonstrates PEG implementation of this. _______________________________________________ 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/APKN7A... Code of Conduct: http://python.org/psf/codeofconduct/
Most of programming languages out there have switch-case statements. Python doesn't have support for switch-case statements though. switch-case statements can sometimes be nice and tidy and sometimes it may be a horrible nightmare. But that also applies to if-elif-else statements. It would be nice to have switch-case statements support in python.
See the pattern-matching PEPs such as https://www.python.org/dev/peps/pep-0634/ In short, python soon will have a sort of switch statement, though the semantics will be a bit different and it is actually a form of pattern matching. See also the notes on pattern mathing in https://docs.python.org/3.10/whatsnew/3.10.html - DLD
This thread is closed therefore. (It was mistakenly opened due to misunderstanding.)
participants (5)
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Antal Gábor -
Brandt Bucher -
Daniel Moisset -
David Lowry-Duda -
Shreyan Avigyan