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Python's pre-declared constants are kinda weird

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Re: Python's pre-declared constants are kinda weird

#41

Post by rcxdude »

plant-ian wrote: post #20
nneonneo wrote: post #12

The __debug__ constant is really weird - any block of code guarded with `if __debug__:` will be entirely omitted from the bytecode under PYTHONOPTIMIZE=1. This and `assert` are the only two examples of real “conditional compilation” in Python. This is also the reason why you cannot assign to __debug__: doing so would make it possible to invalidate the compiler’s assumption about `if __debug__:` statements.

I honestly have never even heard of this constant and I feel like I've been using python for a pretty long time. Although maybe my memory for some things just gets garbage collected if I don't use it enough. Does it actually get used that often in real world code? Seems like it might be kind of risky.

I feel like it's the kind of thing you might wind up caring about if you're micro-optimizing your python, but in my experience that's a losing game and you're better served rewriting it in another language than bothering with trying to speed up the execution of the raw python code (it's not that you can't optimize python code, but only in broader strokes. If you are looking at the bytecode you're in too deep and every time I've seen it tried the code has been ported shortly afterwards).

Re: Python's pre-declared constants are kinda weird

#42

Post by mjr00 »

hmokiguess wrote: post #34

Python is awful. There are so many one offs in libraries, none agree on a style, it’s slow, and it’s way too easy to do the wrong thing. I often work with data scientists and have to productionize their jupyter notebooks which is pure suboptimal hell. I guess it must be a good easy learning curve for research/scratchpad

> Python is awful.

> I often work with data scientists and have to productionize their jupyter notebooks

I'm not a huge Python fan, despite working with it fulltime, but this feels like mixing correlation and causation. Data scientists would not be writing good, optimized code in any language.

Re: Python's pre-declared constants are kinda weird

#43

Post by slashdave »

mjr00 wrote: post #42
hmokiguess wrote: post #34

Python is awful. There are so many one offs in libraries, none agree on a style, it’s slow, and it’s way too easy to do the wrong thing. I often work with data scientists and have to productionize their jupyter notebooks which is pure suboptimal hell. I guess it must be a good easy learning curve for research/scratchpad

> Python is awful. > I often work with data scientists and have to productionize their jupyter notebooks I'm not a huge Python fan, despite working with it fulltime, but this feels like mixing correlation and causation. Data scientists would not be writing good, optimized code in any language.

Well, yeah. You might need to bring an R notebook into production.

Re: Python's pre-declared constants are kinda weird

#44

Post by ks2048 »

hmokiguess wrote: post #34

Python is awful. There are so many one offs in libraries, none agree on a style, it’s slow, and it’s way too easy to do the wrong thing. I often work with data scientists and have to productionize their jupyter notebooks which is pure suboptimal hell. I guess it must be a good easy learning curve for research/scratchpad

> it’s slow

For little utilities, it’s faster than a lot of alternatives - just start the interpreter, no compilation needed.

It’s all relative, but if you view it as replacing bash scripts for renaming files or running other tools, it’s 100x better.

Re: Python's pre-declared constants are kinda weird

#45

Post by slashdave »

moomoo11 wrote: post #25

just my 2c but py is honestly one of the worst languages and ecosystems i’ve used in my life. for all the hate js used to get, py is at least a few magnitudes worse. my opinion ofc. don’t get mad xD

Glass house? Was Python written in a bar?

Re: Python's pre-declared constants are kinda weird

#46

Post by wredcoll »

plant-ian wrote: post #17
echelon wrote: post #4

I used to like Python in the 2010s when it felt like a breath of fresh air relative to PHP and Perl. Now it feels like a weird PHP itself that is slow, brittle, and dangerous to write code at scale in. The loose typing, potluck standard library, and horrible package manager (insofar as the community does not know how to package code) all feel so dated.

I felt the same way about moving to Python versus PHP and Perl. I still really enjoy using python though. It's not really a fair comparison because I hadn't used PHP and Perl for as long but I just don't hit some mystifying issue every single session like I did with those languages when I'm using python. I honestly have never even read about that __debug__ constant. It's fun to hear about it but it's just not somethi…

Perl is a lot like that also, you can read about some really weird old features like $[ but you never see that in practice, you just write code with variables and functions and so on.

Re: Python's pre-declared constants are kinda weird

#47

Post by Numerlor »

nneonneo wrote: post #12

The __debug__ constant is really weird - any block of code guarded with `if __debug__:` will be entirely omitted from the bytecode under PYTHONOPTIMIZE=1. This and `assert` are the only two examples of real “conditional compilation” in Python. This is also the reason why you cannot assign to __debug__: doing so would make it possible to invalidate the compiler’s assumption about `if __debug__:` statements.

If 0. Etc. are also compiled out, at compile time __debug__ is simply False or True and the existing optimization paths take care of it.

Assigning to __debug__ wouldn't do anything to the compiler as it never actually reads the variable, so assignment would just cause weirdness from other use

Re: Python's pre-declared constants are kinda weird

#48

Post by kalenx »

adamddev1 wrote: post #10
echelon wrote: post #4

I used to like Python in the 2010s when it felt like a breath of fresh air relative to PHP and Perl. Now it feels like a weird PHP itself that is slow, brittle, and dangerous to write code at scale in. The loose typing, potluck standard library, and horrible package manager (insofar as the community does not know how to package code) all feel so dated.

I don't understand how people talk about how Python is "easy to learn for beginners" or "easy to understand." To me it's so hard to remember and follow all the weirdness. Racket / Scheme / I dare say even Haskell would just be so much simpler for learners. I'm with Conal Elliot when he said on Type Theory for All that it is sooo much harder to understand a program in Python.

I can understand that "advanced" python programs may be difficult to understand for beginners (lots of implicit/hidden behaviors, possibility to change basically everything one should expect, etc).

But to _learn_ programming, I really, really don't see how using Haskell would be simpler than Python. Perhaps if you have a specific background (e.g., math), but else python is almost pseudo code already. You'll really have to convince me that a more abstract language is better...

Re: Python's pre-declared constants are kinda weird

#49

Post by wredcoll »

Chu4eeno wrote: post #33
Vedor wrote: post #28

Earlier quoted context omitted.

I'm not mad, but curious - I use Python for years and only dabbled with JS. Could you elaborate what makes Python magnitide worse than JavaScript?

Don't mind the web designers calling themselves engineers. There's a lot of annoying issues with Python, but compared to the billions of dollars and thousands of man hours that has been spent trying to fix Javascript and how horrible it still is, it's a perfectly cromulent language.

There are two kinds of languages, ones that people complain about and ones nobody uses.

Re: Python's pre-declared constants are kinda weird

#50

Post by applfanboysbgon »

hmokiguess wrote: post #34

Python is awful. There are so many one offs in libraries, none agree on a style, it’s slow, and it’s way too easy to do the wrong thing. I often work with data scientists and have to productionize their jupyter notebooks which is pure suboptimal hell. I guess it must be a good easy learning curve for research/scratchpad

Python is amazing compared to writing bat/sh scripts. Different languages are for different purposes, using eg. Rust to write system scripts would just be mental. Whether people abuse those languages for purposes they were not intended for is another story, but that doesn't mean the language is inherently bad. And I mean,

> and it’s way too easy to do the wrong thing

is there another programming language where you believe a data scientist is going to have an easier time writing correct code than Python? Do you think C or Rust or JavaScript or C# make it harder to do the wrong thing?

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