Python is slow

[bruno.desthuilliers at gmail.com]

On 23 mai, 10:42, "inhahe" <inh... at gmail.com> wrote:
> "Bruno Desthuilliers" <bruno.42.desthuilli... at websiteburo.invalid> wrote in
> messagenews:4836772e$0$6097$426a74cc at news.free.fr...
>
> > Brad a écrit :
> >> cm_gui wrote:
> >>> Python is slow.
>
> >> It ain't C++, but it ain't a punch card either... somewhere in between. I
> >> find it suitable for lots of stuff. I use C++ when performance really
> >> matters tho... right tool for the job. Learn a good interpreted language
> >> (Pyhton) and a good compiled language (C or C++)
>
> > LordHaveMercy(tm). Could you guys please learn what you're talking about?
>
> > 1/ being interpreted or compiled (for whatever definition of these
> > terms) is not a property of a language, but a property of an
> > implementation of a language.
>
> That's like saying being spherical is not a property of planets, it's a
> property of an instanciation of a planet.

I do definitively not have the required knowledge to say anything
about "being spherical" being part of the definition of what a
"planet" is or not.

>, and b) It's a far cry to
> imagine a planet coming into being that's not spherical

Idem

>  (a language as
> dynamic as Python, or most other scripting languages, would be either
> extremely difficult or impossible to make a native compiler for).

Now this I can tell is false. The problem is not that it's difficult
to "make a native compiler for" dynamic languages, the problem is that
it's difficult to write native compiler for dynamic languages that
generates code that beats the VM/byte-code interpreter/whatever you
name it to be wotrh the effort.

> I guess I
> should also mention that Python isn't very practical (as in "suitable",
> "right tool for the job", and "perfomance", as mentioned in the above post)
> without an implementation.

That is debatable. There are algorithm courses taught in "pseudo-code"
- that is, a language that doesn't have any known implementation.

> So I don't think this distinction has any use
> other than to beat other people over the head with a bat.

Ok, *you* know this - I mean, the distinction between a language and a
language's implementation(s).  Are you sure everyone saying - or
reading - assertions such as "language XXX is slow" or "compiled
languages are faster" etc really know what they're talking about ?

> > 2/ actually, all known Python implementations compile to byte-code.
>
> Which is then interpreted, but you're still technically right, because
> "compiled" can mean either compiled to bytecode or compiled to native code,
> despite what it actually did mean.  Semantics FTW!!

Yes, semantics. But a bit more than semantics - byte-code interpreters
are usually way faster than "pure" interpreter, and start to be fast
enough for quite a lot of practical use.

Ok, I'll stop on this - once again, sorry for the noise, and please
bear with me, I tend to be a bit too much on the pedantic side
sometimes. But still, thanks to the pedantics peoples on usenet that
taught me so much so far and still teach me more and more...