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What’s New in Python 3.8

docs.python.org

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Re: What’s New in Python 3.8

#191

Post by eru »

chooseaname wrote: post #77
smitty1e wrote: post #33

Earlier quoted context omitted.

. . .and the threat of Just Another Vict'ry Announcement (JAVA) as the need to add "sizzle" to the next version looms.

Rock and a hard place, no? Either you keep adding to a language and people keep using it, or you stop adding to a language and people call it a dead language and stop using it. Most devs don't understand that software can be done and still be useful.

Well, you could also try to remove from the language.

Like how they removed the `print` keyword when going from Python 2 to Python 3.

But removing is harder than adding.

Re: What’s New in Python 3.8

#193

Post by eru »

bitcurious wrote: post #38
robocat wrote: post #30

def f(a, b, /, c, d, *, e, f): Wow: IMHO that is a very ugly syntax to define a fn with 6 parameters, although it looks to be a path dependency on previous decisions (*, and CPython ,/) and clearly there was much discussion of the need for the functionality and the compromises: https://www.python.org/dev/peps/pep-0570/ It amazes me to see how certain features make it into languages via community/committee (octal numb…

I’d argue that written maths is worse with its overloading of the Greek alphabet. Although in the case of maths I’d argue that it’s a result of how slowly we write, with the programming equivalent usually being a variable name (autocompleteable).

Yes, math is a much bigger culprit. Including for operator overloading.

Their saving grace is that humans are more intelligent interpreters.

If you ever try to translate a human-readable proof, even a fairly formal and rigorous one, into a computer proof assistant like Agda or Coq, you can see all the little ways humans cut corners.

Re: What’s New in Python 3.8

#194

Post by bandrami »

drdaeman wrote: post #86
geofft wrote: post #69

Earlier quoted context omitted.

> The "walrus operator" will occasionally be useful, but I doubt I will find many effective uses for it. The primary one I want is if m := re.match(...): print(m.group(1)) and while s := network_service.read(): process(s) both of which are both clearer and less error-prone than their non-walrus variants. The other one that I would have found useful an hour ago is in interactive exploration with comprehensions. I freq…

Coming from Perl, I used to want this badly, but then I thought that there's absolutely nothing wrong with m = re.match(...) if m is not None: pass Now, I wonder what you meant saying that single-line version is less error-prone, because I don't think so. I believe they're exactly the same in this regard, except for a bizarre case when someone would bastardize the code by putting some irrelevant lines between the ass…

I mean, what you really want in this case is Perl's =~ operator, as well as the implicit $_ variable.

Re: What’s New in Python 3.8

#195

Post by eru »

falcor84 wrote: post #15
heavenlyblue wrote: post #8

Earlier quoted context omitted.

One thing I vastly dislike with them is that they are still expanded in logging, while they are not expanded when logging is using "the old way".

How would you fix the issue without breaking existing semantics? The way I see it, it's a necessary price to pay, and I just continue to use c-style forming strings in logging.

The clean way would be to introduce laziness. But yeah, can't do that in Python.

Re: What’s New in Python 3.8

#196

Post by Kwpolska »

kps wrote: post #118
robocat wrote: post #98

Earlier quoted context omitted.

That's like visual puns, and is limited to whatever symbols seemed important to the developer at the time. How do you discover how to type ß, °, «, ‡ etc? Android's gboard uses phonetics (long press [s] key for ß), symbolic similarity (long press [*] key for ‡) and visual similarity (long press [<] key for «) which is guessable for some symbols, but isn't discoverable for others (you can search for emoji by name, but…

It's easy on the Mac to have a custom or purpose-built keyboard layout that makes sense for the user or context. It's a little harder with X (mostly due to uncoöperative DEs) but still doable.

I've hacked /usr/share/X11/xkb/symbols/xx files to have custom keyboard layouts, DEs are not able to mess with it.

Re: What’s New in Python 3.8

#197

Post by eru »

xapata wrote: post #186
mintplant wrote: post #76

Buried in the notes for the `typing` module: > “Final” variables, functions, methods and classes. See PEP 591, typing.Final and typing.final(). The final qualifier instructs a static type checker to restrict subclassing, overriding, or reassignment: > pi: Final[float] = 3.1415926536 As I understand it, this means Python now has a way of marking variables as constant (though it doesn't propagate into the underlying va…

I don't see the point of `final` without an optimizing compiler. Name mangling is sufficient for stashing references to avoid accidental side-effects of overriding.

You can guard yourself against overriding in the same module this way, too.

For name mangling, I think you need to start your variable with underscores, and then it won't be accessible for reading outside the module either?

Re: What’s New in Python 3.8

#198

Post by Kwpolska »

grincho wrote: post #85
robocat wrote: post #56

Earlier quoted context omitted.

There are programming fonts that use ligatures to convert >= to ≥, or -> to →, so the source code remains in ASCII but symbol sequences show as unique Unicode characters. A next step could be for common dev environments to actually convert symbol/key sequences to operators (how do APL programmers do it?) Avoiding ambiguity and semantic overloading of ASCII symbols would surely help beginners (if also given a UI that…

The Mac has provided easy access to symbols since 1984, with nice mnemonics like these: option-= ≠ option- ≥ option-/ ÷ option-o ø option-w ∑ I don't know why other OSes haven't adopted something similar. The first couple of these were even idiomatic in HyperCard's scripting language.

Windows has a keyboard called US-International with extra symbols. Also, note that those key combinations might not exist in other keyboard layouts (replaced with local keys).

Re: What’s New in Python 3.8

#199

Post by bandrami »

jp_sc wrote: post #133
paulddraper wrote: post #73

Earlier quoted context omitted.

> As a developer who has primarily developed applications in Python for his entire professional career, I can't say I'm especially excited about any of the "headlining" features of 3.8. Python is a fairly old, mature language. What features would you have been especially excited about?

I would love if they added "?" to the list of valid characters for names, so I could write something like `valid?()` instead of ``is_valid()`.

just use "_P", a fairly-widely-recognized substitute from the Lisp world.

Re: What’s New in Python 3.8

#200

Post by [deleted] »

Tommah wrote: post #101
kolinko wrote: post #39

Earlier quoted context omitted.

I actually found an immense use for Walrus - used it to hack Python into doing pattern matching that is way more readable than without it: https://github.com/eveem-org/panoramix (source code for Eveem.org, which is arguably the best decompiler for Ethereum smart contracts out there. you can see a lot of pattern matching in pano/simplify.py , and I found no way to do it without extending the language/walrus while main…

There is a similar trick that you can use without the walrus operator. I wrote the code many years ago and I am reproducing this from memory, so the code below may be a little off. Define this class: class Any: def __eq__(self, other): self.value = other return True Then you can use an instance of it as the hole in a pattern. My use case was performing peephole optimizations in a simple 6502 assembler. For example, i…

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