On 2022-04-05 12:17 a.m., Chris Angelico wrote:
On Tue, 5 Apr 2022 at 13:00, Steven D'Aprano wrote:
Sure, we can demand that every application that needs to deal with US
survey miles and imperial miles and international miles give them all
distinct names. That's one solution, but not the
On Tue, 5 Apr 2022 at 13:00, Steven D'Aprano wrote:
>
> On Tue, Apr 05, 2022 at 04:02:24AM +1000, Chris Angelico wrote:
>
> > Is it really that much of a problem? Tell me: How often do you REALLY
> > expect to have collisions within an application, but in different
> > modules? YAGNI.
>
> You
On Tue, 5 Apr 2022 at 11:44, Steven D'Aprano wrote:
>
> On Tue, Apr 05, 2022 at 04:36:24AM +1000, Chris Angelico wrote:
>
> > Some unit cancellations really do result in pure scalars. The ratio of
> > a circle's circumference to its diameter isn't a unit of m/m any more
> > than the ratio of a
On Tue, Apr 05, 2022 at 04:02:24AM +1000, Chris Angelico wrote:
> Is it really that much of a problem? Tell me: How often do you REALLY
> expect to have collisions within an application, but in different
> modules? YAGNI.
You have no idea how many different definitions there are for "mile", do
On 4/04/22 3:45 pm, David Mertz, Ph.D. wrote:
An electron volt is a unit of energy. Or of mass. Or of momentum.
Well, in relativity they're all really the same thing, or
at least interconvertible.
But there are more glaring examples of this. What do you get
when you multiply a number of
On Mon, Apr 4, 2022 at 7:45 PM Ethan Furman wrote:
> On 4/4/22 13:31, David Mertz, Ph.D. wrote:
>
> > You should probably change the thread subject to "All-and-only 7 SI
> units" if that's what you mean.
>
> While I'm sure SI would be very useful, I suspect that any system will
> have to be
On Mon, Apr 04, 2022 at 11:05:54AM -0700, Ethan Furman wrote:
> On 4/4/22 08:54, Ken Kundert wrote:
> It seems to me that these "unitless' units actually have units, even if
> they *appear* to cancel each other out.
The term is *dimensionless* units.
1 dozen and 1 mole of objects both are
On Mon, Apr 04, 2022 at 04:44:58PM -0700, Ethan Furman wrote:
> Beyond that, do we make Python smart enough to, for example, convert
> `km*km` to `km^2`, or do we let libraries provide their own functions? I'm
> inclined to let libraries provide their own, as they could also implement
> unit
On 4/04/22 2:42 pm, Ricky Teachey wrote:
height = 5ft + 4.5in
Surely we ought to be able to add these values. But what should the
resulting tag be?
One answer might be that the tag only tracks what kind of quantity it
is -- length, mass, time, etc. Internally the number would be
represented
On Tue, Apr 05, 2022 at 04:36:24AM +1000, Chris Angelico wrote:
> Some unit cancellations really do result in pure scalars. The ratio of
> a circle's circumference to its diameter isn't a unit of m/m any more
> than the ratio of a circle's area to that of a circumscribed square is
> a unit of
On 4/04/22 10:47 am, dn wrote:
You wouldn't believe it - have interrupted typing here to receive a
package. However, the clothing delivered is NOT the size ordered...
Let me guess, you ordered it in cm but they delivered it in inches?-)
--
Greg
___
On 4/4/22 13:31, David Mertz, Ph.D. wrote:
> You should probably change the thread subject to "All-and-only 7 SI units" if
that's what you mean.
While I'm sure SI would be very useful, I suspect that any system will have to be useful for a much broader audience to
be accepted; given the vast
Paul Moore writes:
> this is the first time you've explicitly stated this
this was more explicitely stated earlier in the thread yeah, I honestly can't
blame you for not reading it all.
I'll eventually try to give a quick state of today's proposal to keep it up to
date. I won't have time for
Chris Angelico writes:
> If you meant it only for me, you could have sent it privately.
Well.. yeah, i probably sould have.
I apologise for that.
> But since you are clearly not returning the favour, I am now done.
> Good luck with your proposal, maybe you can team up with jmf and make
> a new
Paul Moore writes:
> > super(A, self) does not proxy to A, but to the first *after* A in MRO order.
> Correct, that's how it's defined to work.
Glad we're on the same page so far.
I love you profile pic by the way
> That's the point - the type
> argument to super() can be omitted in 99% of cases
On Mon, 4 Apr 2022 at 22:19, malmiteria wrote:
> What i am saying is that *if* super(A, self) *were* to call A's method, that
> would be a simpler API.
I understand that you're specifically responding to Chris, but to be
honest, this is the first time you've explicitly stated this (unless
it
On Tue, 5 Apr 2022 at 07:21, malmiteria wrote:
>
> Just for everyone reading this, I'm writing this one only for Chris Angelico.
> As much as some others here have been heating up during the discussion, which
> is understandable, i believe most of you were willing / able to provide a
> fair
Just for everyone reading this, I'm writing this one only for Chris Angelico.
As much as some others here have been heating up during the discussion, which
is understandable, i believe most of you were willing / able to provide a fair
discussion, and still are, which shows maturity, and is
You should probably change the thread subject to "All-and-only 7 SI units"
if that's what you mean.
On Mon, Apr 4, 2022 at 1:46 PM Brian McCall
wrote:
> > I drove 20 minutes up the road to by a bushel (US, not British) of U.S.
> No. 1. apples, to make apple cider. On my return trip, I stopped
>
> Units have infinite precision, so grades and tolerances are also
> irrelevant.
>
Not if you believe in Planck lengths (or quantum states) :-).
--
Keeping medicines from the bloodstreams of the sick; food
from the bellies of the hungry; books from the hands of the
uneducated; technology from
On Tue, 5 Apr 2022 at 05:47, Steven D'Aprano wrote:
>
> On Mon, Apr 04, 2022 at 03:39:26PM +1000, Chris Angelico wrote:
>
> > I would say that 2.54in/1cm should be equal to 1.
>
> 2.54 inches is not 1 cm. This is how you get a billion dollar spacecraft
> crashing into Mars instead of landing
On Tue, 5 Apr 2022 at 05:44, Steven D'Aprano wrote:
> > Should 2.54 in / 1 cm evaluate to 2.54 in/cm or should
> > it evaluate to 1? I'd much rather it evaluate to 1
>
> There are only two reasonable ways to parse that, depending on
> precedence of units and operators:
>
> * (2.54 inches) / (1
On Mon, Apr 04, 2022 at 03:39:26PM +1000, Chris Angelico wrote:
> I would say that 2.54in/1cm should be equal to 1.
2.54 inches is not 1 cm. This is how you get a billion dollar spacecraft
crashing into Mars instead of landing softly :-)
--
Steve
On Mon, Apr 04, 2022 at 04:22:25AM -, Brian McCall wrote:
[Chris]
> > Part of the problem here is that Python has to be many many things.
> > Which set of units is appropriate? For instance, in a lot of contexts,
> > it's fine to simply attach K to the end of something to mean "a
> >
On Mon, Apr 04, 2022 at 06:16:49AM -, Brian McCall wrote:
> So a comprehensive implementation of units would not require more than
> 160 units, and in reality, a "sufficient" implementation would need
> only 7.
The idea that a system which only supported the seven SI base
quantities, and
On Mon, Apr 04, 2022 at 05:45:52PM -, Brian McCall wrote:
> Anyway, you mentioned you knew of at least 1000 units. I count 7. You have
> another 993?
Will 2451 do?
[steve@ando ~]$ units
2438 units, 71 prefixes, 32 nonlinear units
--
Steve
___
On Tue, 5 Apr 2022 at 04:19, Ethan Furman wrote:
>
> On 4/3/22 22:39, Chris Angelico wrote:
> > On Mon, 4 Apr 2022 at 14:22, Brian McCall wrote:
>
> >> Related to these questions, there is the question of what to do about
> mixed systems?
> > Should 2.54 in / 1 cm evaluate to 2.54 in/cm or
On Mon, Apr 4, 2022 at 2:24 PM Steven D'Aprano wrote:
> On Sun, Apr 03, 2022 at 10:42:16PM -0400, Ricky Teachey wrote:
>
> > I was cheerleading this effort earlier and I still think it would be a
> > massive contribution to needs of the engineering world to solve this
> > problem at the language
> For example, consider currencies. There are currently hundreds of national
> currencies and thousands of cryptocurrencies. They all have the same basic
> fundamental unit of “value”, but value is only loosely defined. Furthermore,
> there is no fixed ratio between the currency and its
On Mon, 4 Apr 2022 at 18:59, malmiteria wrote:
> super(A, self) does not proxy to A, but to the first *after* A in MRO order.
Correct, that's how it's defined to work.
> When you're actually in need to passing arguments to super, you very likely
> know what class you're gonna be targeting, and
On Sun, Apr 03, 2022 at 10:42:16PM -0400, Ricky Teachey wrote:
> I was cheerleading this effort earlier and I still think it would be a
> massive contribution to needs of the engineering world to solve this
> problem at the language level. But boy howdy is it a tough but of a problem
> to crack.
On 4/3/22 22:39, Chris Angelico wrote:
> On Mon, 4 Apr 2022 at 14:22, Brian McCall wrote:
>> Related to these questions, there is the question of what to do about mixed
systems?
> Should 2.54 in / 1 cm evaluate to 2.54 in/cm or should it evaluate to 1?
>
> I would say that 2.54in/1cm should be
On Tue, 5 Apr 2022 at 03:58, malmiteria wrote:
>
> Steven D'Aprano writes:
> > > feature 1 (of super alone): proxying the parent.
> > > What most people think super does (and expect it to do):
> > > it allows to call method from *the* (most people don't think of
> > > multiple inheritance)
On 4/4/22 08:54, Ken Kundert wrote:
> Now consider the issue of “unitless units”. In electrical circuit we often
talk
> about gain, which it the ratio between the signal level at the output of
> a circuit relative to the signal level at the input. But you need to be
> specific about how you
On Tue, 5 Apr 2022 at 03:58, Marco Sulla wrote:
>
> On Mon, 4 Apr 2022 at 07:47, Chris Angelico wrote:
> >
> > Not a particle physicist, so I don't know what the usage actually is,
> > but wouldn't mass actually be eV/c²? If that's frequently written as
> > simply "eV", then that's another
On Tue, 5 Apr 2022 at 00:48, Brian McCall
wrote:
>
> Asked and answered!
>
> > * There are an unlimited number of derived (non-SI) and compound units
> > that people will want to use.
>
> Unlimited? You sure that problem can't be bounded? There are few things I can
> think of that could bound
Steven D'Aprano writes:
> > feature 1 (of super alone): proxying the parent.
> > What most people think super does (and expect it to do):
> > it allows to call method from *the* (most people don't think of
> > multiple inheritance) parent.
> For single inheritance, that is exactly what it does,
> I drove 20 minutes up the road to by a bushel (US, not British) of U.S. No.
> 1. apples, to make apple cider. On my return trip, I stopped at the hardware
> store to buy a 2 lb box of 1-3/4" ring shank 12 penny nails. I used my 7/8
> hole kitchen planer blade to grate the apples, then
On Mon, Apr 4, 2022 at 11:55 AM Ken Kundert wrote:
> I think there is one more point worth making here. There is a suggestion
> that
> dimensional analysis can underpin a units system. Actually, the idea that
> all
> units can be broken down into a small set of fundamental units is very
>
On Mon, Apr 04, 2022 at 07:46:12AM -, Brian McCall wrote:
> Now do it for NumPy arrays
In response to Greg:
[quoting Greg]
I'm not convinced there's a need for new syntax here.
63*lbs
77*km/hr
With appropriate definitions of lbs, km and hr these
can be made to construct numbers
On Mon, 2022-04-04 at 09:14 -0700, Ken Kundert wrote:
> As why it is naive, see my previous post where I talk about the
> limitations of dimensional analysis.
>
> As a point of reference, I have been developing software for
> electrical engineers for over 40 years. That software uses physical
>
Greg Ewing writes:
> 1. You hate the existing MRO and super() mechanism with a passion
> and want to rip it out.
I don't hate it, I believe it makes for the most misunderstood python feature
for a reason, and i'm trying to adress it.
> 2. People have objected that this would remove useful
Steven D'Aprano writes:
> I think that where malmiteria gets it wrong is that he thinks that super
> is broken
I do not, i think its design could be improved overall, but i don't think it's
broken. At best I'd argue it can't be used in all of the use case you'd expect
for it.
> Changing super
Just to elaborate on units I use, here's a hypothetical (not stuff that
actually happened today, but very commonplace nature):
I drove 20 minutes up the road to by a bushel (US, not British) of U.S. No.
> 1. apples, to make apple cider. On my return trip, I stopped at the
> hardware store to buy
As why it is naive, see my previous post where I talk about the limitations of
dimensional analysis.
As a point of reference, I have been developing software for electrical
engineers for over 40 years. That software uses physical quantities (voltage
current, resistance, capacitance, etc.)
As why it is naive, see my previous post where I talk about the limitations of
dimensional analysis.
As a point of reference, I have been developing software for electrical
engineers for over 40 years. That software uses physical quantities (voltage
current, resistance, capacitance, etc.)
I think there is one more point worth making here. There is a suggestion that
dimensional analysis can underpin a units system. Actually, the idea that all
units can be broken down into a small set of fundamental units is very limiting
and results in many vexing issues.
For example, consider
> Much of this discussion is based on a misconception. Units and SI scale
> factors
> are very useful in software that describes or interacts with the real world,
> but
> primarily on input and output. They are not normally used for internal
> calculations. The idea that one carries units
Asked and answered!
> * There are an unlimited number of derived (non-SI) and compound units
> that people will want to use.
Unlimited? You sure that problem can't be bounded? There are few things I can
think of that could bound this problem in a performance-friendly manner.
In terms of the
Asked and answered! Although, see below*, the additional representations of
these numbers does not mean that "int", "bool", and "float" have no place in
the core language.
*Here is a URL to a GIF of the good people of Letterkenny saying "to be fair":
Back in my original post, I pointed out that engineers and scientists in their
modern day workflows are expected to have basic programming language skills,
and are expected to use those skills when pre-packaged software solutions leave
gaps in their workflows, but they are explicitly told that
On Mon, Apr 4, 2022 at 3:53 AM Chris Angelico wrote:
> The 160 units would be more likely to have collisions though. Also,
> the base and derived SI units will be used with magnitude prefixes,
>
The supposed 160 are far fewer than I use on a daily (or at least weekly)
basis. Yes, all the rest
On Mon, Apr 04, 2022 at 08:28:31AM +1000, Chris Angelico wrote:
> What do you intend for dependency injection to do with this scream
> method? What would make sense? You've already designed something that
> works differently.
I don't know why malmiteria keeps talking about dependency injection.
On Mon, Apr 4, 2022, 2:17 AM Brian McCall
> For instance, I don't think there would be much uproar if "teaspoons"
were left out of any kind of implementation.
Apparently someone other than you does the cooking in you household!
___
Python-ideas mailing
On Sun, Apr 03, 2022 at 03:09:18PM -, malmiteria wrote:
> feature 1 (of super alone): proxying the parent.
> What most people think super does (and expect it to do):
> it allows to call method from *the* (most people don't think of
> multiple inheritance) parent.
For single inheritance,
On Sun, Apr 03, 2022 at 07:24:42PM -, Brian McCall wrote:
> Let's say we have one of your class-ical ( :D ) geometrical shapes
> hierarchy, including an abstract Shape class.
>
> ```
> class Shape(abc.ABC):
> @abc.abstractmethod
> def area(self):
> ""
The rest of your code
On 2022-04-04 01:19:13, pyt...@shalmirane.com wrote:
> This implies that it is only necessary to provide a package for
> reading and writing physical quantities, and indeed such a package
> exists: QuantiPhy. QuantiPhy came out of the ideas that were raised
> the last time this topic was
On Mon, 4 Apr 2022 at 20:50, Steven D'Aprano wrote:
>
> On Mon, Apr 04, 2022 at 07:17:55PM +1200, Greg Ewing wrote:
> > On 4/04/22 9:35 am, malmiteria wrote:
> > >And just to make it clear, I am not under the impression super can only
> > >target one class.
> > >What i'm saying here is that it is
On Mon, Apr 04, 2022 at 07:17:55PM +1200, Greg Ewing wrote:
> On 4/04/22 9:35 am, malmiteria wrote:
> >And just to make it clear, I am not under the impression super can only
> >target one class.
> >What i'm saying here is that it is the most common impression the average
> >developper would
On Mon, Apr 04, 2022 at 08:27:45AM -, Brian McCall wrote:
> Why don't we allow different libraries to use different, incompatible
> implementations of integers, floating points, and bool?
We do. numpy supports 32-bit and 64-bit ints and possibly others, gmpy
supports mpz integers. I don't
On Mon, 4 Apr 2022 at 18:28, Brian McCall
wrote:
>
> Why don't we allow different libraries to use different, incompatible
> implementations of integers, floating points, and bool? Standard units are
> just as immutable as any of these data types.
>
Those three data types are unambiguous, but
Why don't we allow different libraries to use different, incompatible
implementations of integers, floating points, and bool? Standard units are just
as immutable as any of these data types.
___
Python-ideas mailing list -- python-ideas@python.org
To
Much of this discussion is based on a misconception. Units and SI scale
factors
are very useful in software that describes or interacts with the real world,
but
primarily on input and output. They are not normally used for internal
calculations. The idea that one carries units on variables
On Mon, 4 Apr 2022 at 16:56, Ben Rudiak-Gould wrote:
> I feel like one of the biggest sticking points in this thread is that people
> are arguing for a new kind of global scope just for units, and the sole
> reason seems to be that they want short names for them.
>
> The register_numeric_suffix
On Mon, 4 Apr 2022 at 16:41, Brian McCall
wrote:
>
> How something is used is not the same as how it is defined. I might use my
> car key to open my mail, but if I ask someone if they've seen my letter
> opener, they're probably not going to be able to help me find my car keys.
>
+1 QOTW!
>
Now do it for NumPy arrays
___
Python-ideas mailing list -- python-ideas@python.org
To unsubscribe send an email to python-ideas-le...@python.org
https://mail.python.org/mailman3/lists/python-ideas.python.org/
Message archived at
The C++ way is custom literals (it's where this thread originated)
https://mail.python.org/archives/list/python-ideas@python.org/thread/MFZ52D32YTPYIQVUEZJWW3DUYQUBR5R7/
One problem I am seeing is a misunderstanding between standard, well-defined
units, and technical lingo - for which I am not
On 4/04/22 10:20 am, Chris Angelico wrote:
import sys
sys.register_numeric_suffix("m", lambda n: unit(n, "meter"))
sys.register_numeric_suffix("mol", lambda n: unit(n, "mole"))
A global registry seems like a really bad idea. What if two
libraries want to use different, incompatible
On 4/04/22 9:45 am, Ethan Furman wrote:
Well, if we're spit-balling ideas, what about:
63_lbs
77_km/hr
I'm not convinced there's a need for new syntax here.
63*lbs
77*km/hr
With appropriate definitions of lbs, km and hr these
can be made to construct numbers with attached
On 4/04/22 9:35 am, malmiteria wrote:
And just to make it clear, I am not under the impression super can only target
one class.
What i'm saying here is that it is the most common impression the average
developper would have.
How do you know this? Have you undertaken a survey of
randomly
On 4/04/22 9:12 am, malmiteria wrote:
So, allow me to make it clear, I do get its value. Its value appears in the
other use cases i account for, and wanna provide dedicated features for.
(before getting rid of super and MRO's ability to provide those use case).
So, if I understand correctly:
> The trouble is that SI isn't the only set of units out there. And
> particularly if you support SI derived units, there will be
> innumerable collisions of abbreviations with other systems. Unless
> you're going to mandate *in the language* that SI units are the only
> ones permitted (and thus
On Sun, Apr 3, 2022 at 10:10 PM Chris Angelico wrote:
> On Mon, 4 Apr 2022 at 14:13, Ricky Teachey wrote:
> > What does that idea bring other than being able to say 5.0m
> [...] instead of 5.0*m [...]?
>
> A large amount of clarity, readability, and namespacing (you don't have to
> pollute your
> This is just flatly wrong of usage in particle physics. Electron volts are
> precisely the default units used to describe the mass of subatomic
> particles.
I don't know what to tell you man. Here's Wikipedia. If you follow the link to
the actual SI publication, it says the same thing. How
I think I posted this somewhere else in this thread, or the previous thread.
argparse can handle negative numbers, but only of one of the built-in primitive
types. See example below:
```
import re, argparse
class meters(float):
def __new__(cls, x):
return super().__new__(cls,
> There are thousands of units in use in sciences, commerce, engineering
In the SI system, there are:
7 base SI standard units
22 named, derived standard units
14 alternative standard units of measure that are commensurate with one of the
29 base and derived units, and
~35 units (not symbols)
76 matches
Mail list logo
