Re: =- and -= snag
I don't remember making such a mistake ever before, but it might have happened. -= is a convenient operator so I've probably used it a lot. Anyway, I found that flake8 flagged this as E225 missing whitespace around operator and it's the only linter of pylint, flake8 and pyflake that detects this. Regards, Morten On Wed, Mar 15, 2023 at 5:32 AM Gilmeh Serda wrote: > On Mon, 13 Mar 2023 22:26:20 +0100, Morten W. Petersen wrote: > > > numbers for calculations didn't add up. It went into negative numbers, > > when that shouldn't have been possible. > > We have all written code that makes us wonder why the compiler even > bothered with it and didn't give up on the first line. > > -- > Gilmeh > > If this fortune didn't exist, somebody would have invented it. > -- > https://mail.python.org/mailman/listinfo/python-list > -- I am https://leavingnorway.info Videos at https://www.youtube.com/user/TheBlogologue Twittering at http://twitter.com/blogologue Blogging at http://blogologue.com Playing music at https://soundcloud.com/morten-w-petersen Also playing music and podcasting here: http://www.mixcloud.com/morten-w-petersen/ On Google+ here https://plus.google.com/107781930037068750156 On Instagram at https://instagram.com/morphexx/ -- https://mail.python.org/mailman/listinfo/python-list
Re: =- and -= snag
On 3/14/23 18:50, Rob Cliffe wrote: On 14/03/2023 21:28, avi.e.gr...@gmail.com wrote: Type hints are actually situationally quite useful (though yes, kind of hard to understand when you first come across their use, largely because of things like Union). And I wouldn't recommend their use in all situations because maintaining them is frustrating. xmlschema uses them extensively though and I appreciate them. The module does what I need where all the other offerings failed, and parsing the source because of the subject matter would have been harder to quickly grok without them. Alternatively, I spent quite a while on the subject of pep 232 (before finding the pep) trying to understand it because intuitively I felt like there was something I must be missing. Turns out there isn't. And what my thoughts were assuming was the intent, are discussed under "Future Directions", but when seeing it laid out like that, subjectively the dissenting conclusion of "It opens the way to mind abuse." is more correct. "What if I launch a virtual machine inside a virtual machine inside a virtual machine inside a virtual machine, what happens?"... If I want to have a grouping of minor functionality or attributes on a callable, I can get that with creating a class that defines __call__. I would say 232 is fine for what it is (I don't have to use it, and in many cases it probably is), but the only wide use I know of that I have come across is in the standard library ElementTree: # For tests and troubleshooting register_namespace._namespace_map = _namespace_map Which I hate that variable and it's design with a passion. lol. And exactly, the more a language starts policing my ability to be flexible in my trying to find a creative solution to a problem, the less I want to use it. Sometimes to have something useably beautiful to interact with requires something painfully complex under the surface. Hiding and avoiding all complexity away so you never have to see it or make mistakes prevents you from growing. Anyway, the 20th rule to The Zen of Python is: Don't believe your own bullshit *shrug* -- https://mail.python.org/mailman/listinfo/python-list
Re: =- and -= snag
On Tue, 14 Mar 2023 22:15:34 GMT, Gilmeh Serda wrote: > On Mon, 13 Mar 2023 22:26:20 +0100, Morten W. Petersen wrote: > >> numbers for calculations didn't add up. It went into negative numbers, >> when that shouldn't have been possible. > > We have all written code that makes us wonder why the compiler even > bothered with it and didn't give up on the first line. gcc does have a flag so it will stop on the first error instead of wandering around aimlessly spitting out 100 errors because you missed a curly bracket. Sometimes it's useful. -- https://mail.python.org/mailman/listinfo/python-list
Re: =- and -= snag
"Morten W. Petersen" writes:
> I was working in Python today, and sat there scratching my head as the
> numbers for calculations didn't add up. It went into negative numbers,
> when that shouldn't have been possible.
>
> Turns out I had a very small typo, I had =- instead of -=.
>
> Isn't it unpythonic to be able to make a mistake like that?
Very early versions of C (around 1975 or so, before K was
published) actually used "op=" for compound assignment operators, so
`x =- 2` would subtract 2 from x. It was changed to "=op" (`x -= 2`)
precisely to avoid this ambiguity that programmers kept running
into (people were less generous with whitespace back then).
As late as the late 1990s, I used a compiler (VAXC) that still
recognized the old-style compound assignment operators, though I
think it warned about them.
I thought "Pythonic" was more about how you write code than about the
design of the language. But designing a language syntax so typos are
likely to be syntax errors rather than valid code with different
semantics is an interesting challenge.
--
Keith Thompson (The_Other_Keith) keith.s.thompso...@gmail.com
Working, but not speaking, for XCOM Labs
void Void(void) { Void(); } /* The recursive call of the void */
--
https://mail.python.org/mailman/listinfo/python-list
Re: =- and -= snag
On 14/03/2023 21:28, avi.e.gr...@gmail.com wrote: TThere are people now trying to in some ways ruin the usability by putting in type hints that are ignored and although potentially helpful as in a linter evaluating it, instead often make it harder to read and write code if required to use it. +1 Whenever I see code with type hints, I have to edit them out, either mentally, or physically, to understand what the code is actually doing. It's adding new syntax which I'm not used to and don't want to be forced to learn. Rob Cliffe -- https://mail.python.org/mailman/listinfo/python-list
RE: =- and -= snag
have been great when it was hard to hear a speaker from the back of the theater so the redundancy helped offer possible corrections but these days just makes the language much harder to learn. I vastly prefer a designed language like Esperanto to any human ones that evolved into monstrosities. We have lots of computer languages to choose from and some are designed to protect you from yourself to the extent that I simply have no interest in programming in them. Some take quite a bit of work to even get it to compile so you can then look to see if there are any bugs not caught. Python is towards the other end of a spectrum where the idea is to let you write programs easier. There are people now trying to in some ways ruin the usability by putting in type hints that are ignored and although potentially helpful as in a linter evaluating it, instead often make it harder to read and write code if required to use it. Some programmers like freedom and others like dependability. Of course, freedom is relative and after you have been mugged a few times by your errors, you may decide it is worth getting some protection. So, consider having code reviews where fresh eyes may spot your errors. -Original Message- From: Python-list On Behalf Of Morten W. Petersen Sent: Tuesday, March 14, 2023 4:31 PM To: Jon Ribbens Cc: python-list@python.org Subject: Re: =- and -= snag Hoi. After reading the replies, I think some script / linter etc. is the right thing to do. What's the best linter for Python out there that covers this as well? At first glance I thought =- was a new assignment operator, and this is what seemed unpythonic to me, to have two operators that were so similar. -Morten On Tue, Mar 14, 2023 at 5:31 PM Jon Ribbens via Python-list < python-list@python.org> wrote: > On 2023-03-13, Morten W. Petersen wrote: > > I was working in Python today, and sat there scratching my head as the > > numbers for calculations didn't add up. It went into negative numbers, > > when that shouldn't have been possible. > > > > Turns out I had a very small typo, I had =- instead of -=. > > > > Isn't it unpythonic to be able to make a mistake like that? > > Why would it be? How could it be? Mandating white-space between > operators would be unpythonic. > > That's nothing anyway - yesterday I had an issue in TypeScript which > confused me for a while which turned out to be because 1 + 1 = 11. > (I thought the whole point of TypeScript was to prevent things like > that...) > -- > https://mail.python.org/mailman/listinfo/python-list > -- I am https://leavingnorway.info Videos at https://www.youtube.com/user/TheBlogologue Twittering at http://twitter.com/blogologue Blogging at http://blogologue.com Playing music at https://soundcloud.com/morten-w-petersen Also playing music and podcasting here: http://www.mixcloud.com/morten-w-petersen/ On Google+ here https://plus.google.com/107781930037068750156 On Instagram at https://instagram.com/morphexx/ -- https://mail.python.org/mailman/listinfo/python-list -- https://mail.python.org/mailman/listinfo/python-list
Re: =- and -= snag
Hoi. After reading the replies, I think some script / linter etc. is the right thing to do. What's the best linter for Python out there that covers this as well? At first glance I thought =- was a new assignment operator, and this is what seemed unpythonic to me, to have two operators that were so similar. -Morten On Tue, Mar 14, 2023 at 5:31 PM Jon Ribbens via Python-list < python-list@python.org> wrote: > On 2023-03-13, Morten W. Petersen wrote: > > I was working in Python today, and sat there scratching my head as the > > numbers for calculations didn't add up. It went into negative numbers, > > when that shouldn't have been possible. > > > > Turns out I had a very small typo, I had =- instead of -=. > > > > Isn't it unpythonic to be able to make a mistake like that? > > Why would it be? How could it be? Mandating white-space between > operators would be unpythonic. > > That's nothing anyway - yesterday I had an issue in TypeScript which > confused me for a while which turned out to be because 1 + 1 = 11. > (I thought the whole point of TypeScript was to prevent things like > that...) > -- > https://mail.python.org/mailman/listinfo/python-list > -- I am https://leavingnorway.info Videos at https://www.youtube.com/user/TheBlogologue Twittering at http://twitter.com/blogologue Blogging at http://blogologue.com Playing music at https://soundcloud.com/morten-w-petersen Also playing music and podcasting here: http://www.mixcloud.com/morten-w-petersen/ On Google+ here https://plus.google.com/107781930037068750156 On Instagram at https://instagram.com/morphexx/ -- https://mail.python.org/mailman/listinfo/python-list
Re: =- and -= snag
On 2023-03-13, Morten W. Petersen wrote: > I was working in Python today, and sat there scratching my head as the > numbers for calculations didn't add up. It went into negative numbers, > when that shouldn't have been possible. > > Turns out I had a very small typo, I had =- instead of -=. > > Isn't it unpythonic to be able to make a mistake like that? Why would it be? How could it be? Mandating white-space between operators would be unpythonic. That's nothing anyway - yesterday I had an issue in TypeScript which confused me for a while which turned out to be because 1 + 1 = 11. (I thought the whole point of TypeScript was to prevent things like that...) -- https://mail.python.org/mailman/listinfo/python-list
Re: =- and -= snag
On 3/13/23 17:26, Morten W. Petersen wrote: It went into negative numbers, when that shouldn't have been possible. Turns out I had a very small typo, I had =- instead of -=. Isn't it unpythonic to be able to make a mistake like that? That is why I tell Alice it is always best to stay positive and use x-=-1 to avoid situations like that. *shrugs* -- https://mail.python.org/mailman/listinfo/python-list
Re: =- and -= snag
On 3/13/2023 9:47 PM, Chris Angelico wrote: On Tue, 14 Mar 2023 at 12:38, Thomas Passin wrote: On 3/13/2023 9:07 PM, Chris Angelico wrote: Of course, all this is predicated on you actually putting whitespace around your equals signs. If you write it all crunched together as "x=-5", there's no extra clues to work with. Linters and code reviewers can make use of all the available information, including whitespace, to determine programmer intent. This is the kind of thing that unit tests can catch. Maybe, but that's quite orthogonal. The linter would highlight the exact line of code with the odd whitespace; a unit test would merely point out that the overall behaviour is incorrect, which would have been no further information beyond what the OP already knew (the numbers weren't adding up). ChrisA *This* time the OP happened to know. People in the thread have been discussing how to pick this kind of mistake with linters or what have you. Even with a linter, whether or not this would have been picked up depends on how it has been configured. Really, the only defense against these kind of potential mistakes or typos is not to use constructions that may be more likely to get wrong (or be typoed). In this particular case, that would probably be too great a limitation for most of us. But the general principle is a good one. Douglas Crockford wrote a book on using just the better parts of Javascript (JavaScript: The Good Parts - rather dated by now but still worth the reading). Of course, anyone can have a brain blip on any given day! -- https://mail.python.org/mailman/listinfo/python-list
Re: =- and -= snag
On Tue, 14 Mar 2023 at 12:38, Thomas Passin wrote: > > On 3/13/2023 9:07 PM, Chris Angelico wrote: > > Of course, all this is predicated on you actually putting whitespace > > around your equals signs. If you write it all crunched together as > > "x=-5", there's no extra clues to work with. > > > > Linters and code reviewers can make use of all the available > > information, including whitespace, to determine programmer intent. > > This is the kind of thing that unit tests can catch. > Maybe, but that's quite orthogonal. The linter would highlight the exact line of code with the odd whitespace; a unit test would merely point out that the overall behaviour is incorrect, which would have been no further information beyond what the OP already knew (the numbers weren't adding up). ChrisA -- https://mail.python.org/mailman/listinfo/python-list
Re: =- and -= snag
On 3/13/2023 9:07 PM, Chris Angelico wrote: Of course, all this is predicated on you actually putting whitespace around your equals signs. If you write it all crunched together as "x=-5", there's no extra clues to work with. Linters and code reviewers can make use of all the available information, including whitespace, to determine programmer intent. This is the kind of thing that unit tests can catch. -- https://mail.python.org/mailman/listinfo/python-list
RE: =- and -= snag
Morten, Suggesting something is UNPYTHONIC is really not an argument I take seriously. You wrote VALID code by the rules of the game and it is not a requirement that it guesses at what you are trying to do and calls you an idiot! More seriously, python lets you do some completely obscure things such as check whether some random object or expression is truthy or not. There is no way in hell the language, as defined, can catch all kinds of mistakes. Now some languages or their linters have chosen to provide warnings of code that may be valid but is often an error. Consider: x = 1 y = 0 x = y Do I want to rest x to the value of y? Maybe. Or do I want the interpreter to print out whether x == y perhaps? Well what if the third line above was x == y Is that too a warning? To add to the confusion some languages have an ===, :=, +=, -=, /=, |= or oddities like %=% and many of these are all variations on meanings vaguely related to equality before or after ... So, no, it is not only not unpythonic, in my opinion, but quite pythonic to let the interpreter interpret what you wrote and not know what you meant. Is there possible a flag that would require your code to use spaces in many places that might cut down on mistakes? There could be and so your example of something like "new =- old" might be asked to be rewritten as "new = - old" or even "new = (-old)" but for now, you may want to be more careful. I do sympathize with the problem of a hard to find bug because it LOOKS RIGHT to you. But it is what it is. Avi -Original Message- From: Python-list On Behalf Of Morten W. Petersen Sent: Monday, March 13, 2023 5:26 PM To: python-list Subject: =- and -= snag Hi. I was working in Python today, and sat there scratching my head as the numbers for calculations didn't add up. It went into negative numbers, when that shouldn't have been possible. Turns out I had a very small typo, I had =- instead of -=. Isn't it unpythonic to be able to make a mistake like that? Regards, Morten -- I am https://leavingnorway.info Videos at https://www.youtube.com/user/TheBlogologue Twittering at http://twitter.com/blogologue Blogging at http://blogologue.com Playing music at https://soundcloud.com/morten-w-petersen Also playing music and podcasting here: http://www.mixcloud.com/morten-w-petersen/ On Google+ here https://plus.google.com/107781930037068750156 On Instagram at https://instagram.com/morphexx/ -- https://mail.python.org/mailman/listinfo/python-list -- https://mail.python.org/mailman/listinfo/python-list
Re: =- and -= snag
On 2023-03-14 00:28, Gary Herron wrote: On 3/13/23 2:26 PM, morp...@gmail.com wrote: Hi. I was working in Python today, and sat there scratching my head as the numbers for calculations didn't add up. It went into negative numbers, when that shouldn't have been possible. Turns out I had a very small typo, I had =- instead of -=. Isn't it unpythonic to be able to make a mistake like that? Regards, Morten These all mean the same thing, but I don't see a good way to designate the second or third as an error. x = -5 x=-5 x =- 5 The third one could be picked up as suspicious by a linter due to its unusual spacing. -- https://mail.python.org/mailman/listinfo/python-list
Re: =- and -= snag
On Tue, 14 Mar 2023 at 11:37, Gary Herron wrote: > > > On 3/13/23 2:26 PM, morp...@gmail.com wrote: > > Hi. > > > > I was working in Python today, and sat there scratching my head as the > > numbers for calculations didn't add up. It went into negative numbers, > > when that shouldn't have been possible. > > > > Turns out I had a very small typo, I had =- instead of -=. > > > > Isn't it unpythonic to be able to make a mistake like that? > > > > Regards, > > > > Morten > > > > These all mean the same thing, but I don't see a good way to designate > the second or third as an error. > > > x = -5 > x=-5 > x =- 5 > The second one isn't definitely an error, but the third is a failure of style. Many style guides mandate, for instance, equal whitespace either side of a binary operator. It's pretty straight-forward for a program to tokenize your code the exact same way that Python would, so it will interpret it thus: NAME "x" (whitespace " ") OP "=" OP "-" (whitespace " ") NUMBER "5" The whitespace parts aren't tokens in the normal sense, but worst case, you can count positions. And since there's one space prior to the "=" and none after, it violates the style rule, and can thus be flagged. (This is one reason that I detest autoformatters. You might notice the autoformatter relayout your code into "x = -5", but if you don't spot it right at that moment, there's a lower chance that it'll look like a problem. OTOH, something that simply flags the error and leaves it for you to fix, even if you don't notice it immediately, will bring this line to your attention and let you wonder whether it's misformatted or miscoded.) Of course, all this is predicated on you actually putting whitespace around your equals signs. If you write it all crunched together as "x=-5", there's no extra clues to work with. Linters and code reviewers can make use of all the available information, including whitespace, to determine programmer intent. ChrisA -- https://mail.python.org/mailman/listinfo/python-list
Re: =- and -= snag
On 3/13/23 2:26 PM, morp...@gmail.com wrote: Hi. I was working in Python today, and sat there scratching my head as the numbers for calculations didn't add up. It went into negative numbers, when that shouldn't have been possible. Turns out I had a very small typo, I had =- instead of -=. Isn't it unpythonic to be able to make a mistake like that? Regards, Morten These all mean the same thing, but I don't see a good way to designate the second or third as an error. x = -5 x=-5 x =- 5 Dr. Gary Herron Professor of Computer Science DigiPen Institute of Technology -- https://mail.python.org/mailman/listinfo/python-list
=- and -= snag
Hi. I was working in Python today, and sat there scratching my head as the numbers for calculations didn't add up. It went into negative numbers, when that shouldn't have been possible. Turns out I had a very small typo, I had =- instead of -=. Isn't it unpythonic to be able to make a mistake like that? Regards, Morten -- I am https://leavingnorway.info Videos at https://www.youtube.com/user/TheBlogologue Twittering at http://twitter.com/blogologue Blogging at http://blogologue.com Playing music at https://soundcloud.com/morten-w-petersen Also playing music and podcasting here: http://www.mixcloud.com/morten-w-petersen/ On Google+ here https://plus.google.com/107781930037068750156 On Instagram at https://instagram.com/morphexx/ -- https://mail.python.org/mailman/listinfo/python-list
