why python is slower than java?

[Cameron Laird]

Re: why python is slower than java?

In article <pan.2004.11.05 .09.23.39.24871 8@yahoo.com>,
John Doe <atterdan@yahoo .com> wrote:

[Mike Meyer]

Re: why python is slower than java?

finite.automato n@gmail.com (Lonnie Princehouse) writes:
[color=blue]
> Yes, wxPython is typically quicker than swing. It's not fair to use
> this in a generic Python-vs-Java speed shootout, though, since
> wxPython is just a wrapper around wxWidgets' C++ code; you're really
> comparing C++ vs. Java here.[/color]

Is it unfair to compare Python dictionaries to Java HashTables because
Python is using hand-tuned C where Java is using Java? I'd say that's
a perfectly fair comparison. If that's fair, what's unfair about
comparing graphics toolkits that happen to be written in C rather than
Python (is there a graphics toolkit written in Python?).

That's *how* interpreted languages manage to compete with compiled
languages - they perform the common operations in hand-tuned compiled
code. That people tend to write Java libraries in Java rather than C
just means they're going to get slower libraries.
[color=blue]
> AFAIK the major two reasons for Python's relative slowness are that
> it's interpreted and dynamically typed.[/color]

Java is interpreted just like Python is. The only difference is that
Java splits the compiler and VM implementation into two different
binaries.

<mike
--
Mike Meyer <mwm@mired.or g> http://www.mired.org/home/mwm/
Independent WWW/Perforce/FreeBSD/Unix consultant, email for more information.

[Steve Menard]

Re: why python is slower than java?

Mike Meyer wrote:[color=blue]
> finite.automato n@gmail.com (Lonnie Princehouse) writes:
>
>[color=green]
>>Yes, wxPython is typically quicker than swing. It's not fair to use
>>this in a generic Python-vs-Java speed shootout, though, since
>>wxPython is just a wrapper around wxWidgets' C++ code; you're really
>>comparing C++ vs. Java here.[/color]
>
>
> Is it unfair to compare Python dictionaries to Java HashTables because
> Python is using hand-tuned C where Java is using Java? I'd say that's
> a perfectly fair comparison. If that's fair, what's unfair about
> comparing graphics toolkits that happen to be written in C rather than
> Python (is there a graphics toolkit written in Python?).
>
> That's *how* interpreted languages manage to compete with compiled
> languages - they perform the common operations in hand-tuned compiled
> code. That people tend to write Java libraries in Java rather than C
> just means they're going to get slower libraries.
>
>[color=green]
>>AFAIK the major two reasons for Python's relative slowness are that
>>it's interpreted and dynamically typed.[/color]
>
>
> Java is interpreted just like Python is. The only difference is that
> Java splits the compiler and VM implementation into two different
> binaries.
>
> <mike[/color]

Actually java has not been interpreted for quite a few years. Java today
is compiled to native code at runtime (JIT), exactly like what Psyco
tries to do for Python. This means the only things that (today) makes a
java program slower than a C program are Java's added safety features (
Bounds-checking on arrays and garbage collection to name but two).

Java's speed and Python's speed are not absolute values. Java IS faster
than python when it comes to CPU-intensive operations. IF you given
problem is heavily IO-bound, then python will be just as fast as Java.
Also, if you are writing a GUI application, your program will spend most
of its time waiting for user-input and not much difference will be
noticed. Python may even win out in that case since it's GUI are
typically platform-tuned C/C++ libraries wrapped in Python.


Steve

[Alex Martelli]

Re: why python is slower than java?

Hans Nowak <hans@zephyrfal con.org> wrote:
[color=blue]
> John Machin wrote:
>[color=green]
> > Or is this a joke/troll?? I can't believe the "unimelb.edu.au "; surely
> > a forgery.[/color]
>
> Is it just me, or is the climate in c.l.py getting less friendly to
> newbies? In any case,[/color]

Interestingly enough, I sort of share your perception -- and I have
noticed the same thing, and seen it remarked upon by others, in other,
completely unrelated newsgroups as well, such as it.comp.macinto sh.

It's not, I think, about newbies in general: people who come and post
help requests, without giving the information that's quite obviously
indispensabile to let us help them, keep getting treated with
unreasonable amounts of friendliness and courtesy even after many
requests for more info go unheeded, for example.

However, newbies who are clueless enough to come blasting in with the
usual whines we've heard a zillion times -- Macs cost too much, Python
is too slow, there's no apps for Macs, Python must absolutely add
feature X or it will die, Apple's gonna go broke tomorrow, etc, etc --
do appear to get on our collective nerves worse than their essentially
indistinguishab le precursors did last year, two years ago, &c.

The accusation of being a troll often follows, breaking the old advice
to "Never attribute to malice what can be adequately explained by
incompetence". Maybe it's a case of the corollary to that old advice,
"Sufficient ly advanced cluelessness is indistinguishab le from malice".
But why that should be so this year more than last year, say, is not
clear to me...


Alex

[Maurice LING]

Re: why python is slower than java?

[color=blue]
> Interestingly enough, I sort of share your perception -- and I have
> noticed the same thing, and seen it remarked upon by others, in other,
> completely unrelated newsgroups as well, such as it.comp.macinto sh.
>
> It's not, I think, about newbies in general: people who come and post
> help requests, without giving the information that's quite obviously
> indispensabile to let us help them, keep getting treated with
> unreasonable amounts of friendliness and courtesy even after many
> requests for more info go unheeded, for example.
>
> However, newbies who are clueless enough to come blasting in with the
> usual whines we've heard a zillion times -- Macs cost too much, Python
> is too slow, there's no apps for Macs, Python must absolutely add
> feature X or it will die, Apple's gonna go broke tomorrow, etc, etc --
> do appear to get on our collective nerves worse than their essentially
> indistinguishab le precursors did last year, two years ago, &c.
>
> The accusation of being a troll often follows, breaking the old advice
> to "Never attribute to malice what can be adequately explained by
> incompetence". Maybe it's a case of the corollary to that old advice,
> "Sufficient ly advanced cluelessness is indistinguishab le from malice".
> But why that should be so this year more than last year, say, is not
> clear to me...
>
>
> Alex[/color]

I've already said the following and was not noticed:

1. it is a disk intensive I/O operation.
2. users delay is not in the equation (there is no user input)
3. I am not interested in the amount of time needed to develop it. But
only interested execution speed.

Thanks maurice

[Maurice LING]

Re: why python is slower than java?

[color=blue]
> In this way version 1.0 is all python. v1.1 has 20% C++; v1.2 is 34% C++
> ... until v2.0 is all C++. Each upgrades is faster, but does not introduce
> any new functionality and the risks that new functions imply.
>
> If you were faithful to this concept, version 3 requires you to use the
> oldest python branch who's functions will not be modified, to start
> development. Could be v1.1 or 1.9.
>[/color]
I don't quite get the last part right, the version 3 part. I got lost in
it....

thanks maurice

[Maurice LING]

Re: why python is slower than java?

[color=blue]
>
> Do you have any data to support this ?
> On Windows XP, Windows NT and Linux (Gentoo ), I have consistently
> found python apps using wxpython to be far faster to load
> and to be far more responsive than Java apps.[/color]

well, I do not have data to support this. Just based on an impression,
perhaps seriously flawed impression. maurice

[Harald Massa]

Re: why python is slower than java?

Israel Raj T <rambam@bigpond .net.au> wrote in news:878y9gbkh7 .fsf@pop-
server.bigpond. net.au:
[color=blue]
> On the updated version at http://shootout.alioth.debian.org/craps.php,
> Python beats at least two java implementations .[/color]

Very interesting link, great ressource!!!

What really is disturbing: within the test "hash access" perl2 comes out
first compared with java.

A know that Python dictionaries are the most heavily used datastructure
(because it is allways used within Python itself), and from looking at the
sourcecode there is the line "with help from Raymund Hettinger"; so I am
very sure it is probably THE optimal coding.

So... string processing, regular expression, blablabla no problem; but why
second to perl2 in Hash-access ???

Harald

[gabriele renzi]

Re: why python is slower than java?

Harald Massa ha scritto:[color=blue]
> Israel Raj T <rambam@bigpond .net.au> wrote in news:878y9gbkh7 .fsf@pop-
> server.bigpond. net.au:
>
>[color=green]
>>On the updated version at http://shootout.alioth.debian.org/craps.php,
>>Python beats at least two java implementations .[/color]
>
>
> Very interesting link, great ressource!!!
>
> What really is disturbing: within the test "hash access" perl2 comes out
> first compared with java.
>
> A know that Python dictionaries are the most heavily used datastructure
> (because it is allways used within Python itself), and from looking at the
> sourcecode there is the line "with help from Raymund Hettinger"; so I am
> very sure it is probably THE optimal coding.
>
> So... string processing, regular expression, blablabla no problem; but why
> second to perl2 in Hash-access ???[/color]

maybe because perl has been polished for more years :)
Anyway, 3 things worth noting about the shootou

- you won't *ever* write heapsort and things like that in python,
obviously it is slow, and obviously you have'em builtin.
- there are some tricks like using numarray for matrix calculations
- the ranking system is named CRAP(s).

[Alex Martelli]

Re: why python is slower than java?


On 2004 Nov 06, at 08:31, Maurice LING wrote:
...[color=blue]
> 1. it is a disk intensive I/O operation.
> 2. users delay is not in the equation (there is no user input)
> 3. I am not interested in the amount of time needed to develop it. But
> only interested execution speed.[/color]

OK, could you provide a simple toy example that meets these conditions
-- does lot of identical disk-intensive I/O "in batch" -- and the
execution speed measured (and on what platform) for what Python and
Java implementations , please?

For example, taking a trivial Copy.java from somewhere on the net:

import java.io.*;

public class Copy {
public static void main(String[] args) throws IOException {
File inputFile = new File("/usr/share/dict/web2");
File outputFile = new File("/tmp/acopy");

FileReader in = new FileReader(inpu tFile);
FileWriter out = new FileWriter(outp utFile);
int c;

while ((c = in.read()) != -1)
out.write(c);

in.close();
out.close();
}
}

and I observe (on an iBook 800, MacOSX 10.3.5):

kallisti:~ alex$ java -version
java version "1.4.2_05"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.2_05-141.3)
Java HotSpot(TM) Client VM (build 1.4.2-38, mixed mode)

-r--r--r-- 1 root wheel 2486825 12 Sep 2003 /usr/share/dict/web2

kallisti:~ alex$ time java Copy

real 0m7.058s
user 0m5.820s
sys 0m0.390s

versus:

kallisti:~ alex$ time python2.4 Copy.py

real 0m0.296s
user 0m0.080s
sys 0m0.170s

with Python 2.4 beta 1 for the roughly equivalent:

inputFile = file("/usr/share/dict/web2", 'r')
outputFile = file("/tmp/acopy", 'w')

outputFile.writ e(inputFile.rea d())

inputFile.close ()
outputFile.clos e()

which isn't all that far from highly optimized system commands:

kallisti:~ alex$ time cp /usr/share/dict/web2 /tmp/acopy

real 0m0.167s
user 0m0.000s
sys 0m0.040s

kallisti:~ alex$ time cat /usr/share/dict/web2 >/tmp/acopy

real 0m0.149s
user 0m0.000s
sys 0m0.090s


I'm sure the Java version can be optimized easily, too -- I just
grabbed the first thing I saw off the net. But surely this example
doesn't point to any big performance issue with Python disk I/O wrt
Java. So, unless you post concrete examples yourself, the smallest the
better, it's going to be pretty difficult to understand where your
doubts are coming from!


Alex

[Carlos Ribeiro]

Re: why python is slower than java?

On Fri, 05 Nov 2004 18:33:10 -0500, Hans Nowak <hans@zephyrfal con.org> wrote:[color=blue]
> John Machin wrote:
>[color=green]
> > Or is this a joke/troll?? I can't believe the "unimelb.edu.au "; surely
> > a forgery.[/color]
>
> Is it just me, or is the climate in c.l.py getting less friendly to
> newbies? In any case,
> http://www.zoology.unimelb.edu.au/staff/nicholas.htm mentions Maurice
> Ling as an honor student.[/color]

Not only that, but Maurice Ling has started a long thread a few weeks
looking for a good research topic for his thesis (involving Java &
Python, btw). At some points he was bashed, but went ahead with the
discussion, that ended up touching in several interesting topics.

As for the climate in c.l.py, it's just interesting to note that the
climate *is* getting less friendly, and that it does coincide with
several old-timers moving away from the list. A few years ago I
remember that the likes of Tim Peters, effbot, Skip Montanaro, and
several others (sorry, I would really like to remember more names from
the top of my head) were frequent posters here. They've now moved to
other interests, or are focusing their efforts on the python-dev list.
It must not be a coincidence.

--
Carlos Ribeiro
Consultoria em Projetos
blog: http://rascunhosrotos.blogspot.com
blog: http://pythonnotes.blogspot.com
mail: carribeiro@gmai l.com
mail: carribeiro@yaho o.com

[Carlos Ribeiro]

Re: why python is slower than java?

On Sat, 6 Nov 2004 08:12:10 +0100, Alex Martelli <aleaxit@yahoo. com> wrote:[color=blue]
> "Sufficient ly advanced cluelessness is indistinguishab le from malice".[/color]

Although not originally yours, anyway: +100 QOTW!
[color=blue]
> But why that should be so this year more than last year, say, is not
> clear to me...[/color]

I think that (at least for c.l.py) it has something to do with the
fact that several old-timers are moving away from the list. I don't
know if this is a cause or a consequence. But it's not a coincidence,
IMHO.

--
Carlos Ribeiro
Consultoria em Projetos
blog: http://rascunhosrotos.blogspot.com
blog: http://pythonnotes.blogspot.com
mail: carribeiro@gmai l.com
mail: carribeiro@yaho o.com

[Eric S. Johansson]

Re: why python is slower than java?

Alex Martelli wrote:[color=blue]
> Hans Nowak <hans@zephyrfal con.org> wrote:
>
>[color=green]
>>John Machin wrote:
>>
>>[color=darkred]
>>>Or is this a joke/troll?? I can't believe the "unimelb.edu.au "; surely
>>>a forgery.[/color]
>>
>>Is it just me, or is the climate in c.l.py getting less friendly to
>>newbies? In any case,[/color]
>
>
> Interestingly enough, I sort of share your perception -- and I have
> noticed the same thing, and seen it remarked upon by others, in other,
> completely unrelated newsgroups as well, such as it.comp.macinto sh.[/color]

I think it can be explained by donor fatigue.

I've experienced this on a couple of projects where the initial
developers/intellectual foundation are very helpful and a lot of work
and they get burned out. The Next Generation comes along and doesn't
quite know enough to be able to handout ready answers but tries real
hard and get frustrated. Users get frustrated and then as you point
out, the clueless twits start dominating the conversation. Sort of an
intellectual approximation of Gresham's law.

I know from my perspective, I have been reluctant to really talk much
about what I've done with Python in developing the camram anti-spam
system because of fatigue of a different type. It is a radically
different system and the very odd thing is that ordinary users get it in
a heartbeat and many technologists fight it with every fiber of their being.

so as a result, I ask questions trying to describe the abstract case of
what I'm trying to do so that I don't get distracted down a rathole of
defending the application. Needless to say, I suspect others are doing
the same thing and it's really really hard to describe the abstract case
in a way that's clear.

now I'm going to throw out another radical idea for dealing with donor
fatigue: I will argue that we might want to start including in the
headers of mailing list/newsgroups a dana reference. If you are
familiar with Buddhist culture, dana is an expression of generosity. A
gift given in response to a priceless lesson. There is no expectation
giving and there is no expectation of receiving.
http://www.accesstoinsight.org/ptf/dana.html therefore, with a dana
header, someone who is happy with the answer to a question could gift
some money to the recipient.

I'll argue that some form of compensation system is necessary to help
combat donor fatigue. We all live for reward stimuli be it money, sex,
chocolate. Compulsory "pay for the answer" systems don't work well
because you have no assurance that you'll get an answer you can use.
The flip side "pay for the cheapest answer that meets your needs" does
not encourage participation because it's usually a financial race to the
bottom. I think the middle path of Dana is the most likely to succeed
although it won't make anybody rich. You contribute and maybe somebody
will thank you for it. You'll know that it was given in the spirit of
generosity and kindness, not because of a contractual requirement.

another advantage of this idea is that it builds on the existing
infrastructure of mailing lists and newsgroups not a walled garden of a
web site somewhere.

There are some challenges connecting the dana id to financial systems
and e-mail/news clients. But these are known problems with solutions
and with tools like Thunderbird, we can easily make modifications and
make them available.

---eric

[Kendall Clark]

Re: why python is slower than java?

On Fri, Nov 05, 2004 at 05:58:09AM +0000, Maurice LING wrote:[color=blue]
> This may be a dumb thing to ask, but besides the penalty for dynamic
> typing, is there any other real reasons that Python is slower than Java?[/color]

I favor a different kind of explanation than the ones usually offered
here. While the degree to which Python is "slower than Java" will
depend in large part on what you're trying to do with both of them,
it's also the case that Java leads Python by probably $1 billion
dollars, if not more, in JIT compiler R&D.

The main reason Java is "faster" is because it's been backed by Sun
and IBM, for use in enterprise applications, on some of the biggest
hardware available, and they've put massive R&D effort (i.e., money)
into making it faster.

I suspect if MS had chosen Python instead of C#, and then spent a few
billion and 5 to 10 years of R&D effort, people would be asking why
Perl is so much slower than Python.

Common Lisp is fast because it's had similar R&D effort, spread out
over 40 years or so, going back to the first Lisps. Same goes for
Smalltalk. Java is fast because Sun & IBM and others decided it had to
be. Python is slower because the Python community is incomparably
smaller, less well-heeled, and mostly doesn't care too much about
performance.

There are *technical* reasons for all of this, but I think those
reasons exist largely because of non-technical, social reasons.

My two cents. :>

Best,
Kendall Clark
--
Sometimes it's appropriate, even patriotic, to be ashamed
of your country. -- James Howard Kunstler

[Dan Perl]

Re: why python is slower than java?


"Alex Martelli" <aleaxit@yahoo. com> wrote in message
news:1gmtkpc.1h 26kkr1rd529sN%a leaxit@yahoo.co m...[color=blue]
> Hans Nowak <hans@zephyrfal con.org> wrote:
>[color=green]
>> John Machin wrote:
>>[color=darkred]
>> > Or is this a joke/troll?? I can't believe the "unimelb.edu.au "; surely
>> > a forgery.[/color]
>>
>> Is it just me, or is the climate in c.l.py getting less friendly to
>> newbies? In any case,[/color]
>
> Interestingly enough, I sort of share your perception -- and I have
> noticed the same thing, and seen it remarked upon by others, in other,
> completely unrelated newsgroups as well, such as it.comp.macinto sh.[/color]

I'm still one of the newbies and I was not reading this newsgroup a year
ago, so I cannot draw any comparisons, but I wonder, has this group also
grown much during this time? Could this be a cultural thing like the
difference between a small town culture and a big city culture?
[color=blue]
> It's not, I think, about newbies in general: people who come and post
> help requests, without giving the information that's quite obviously
> indispensabile to let us help them, keep getting treated with
> unreasonable amounts of friendliness and courtesy even after many
> requests for more info go unheeded, for example.
>
> However, newbies who are clueless enough to come blasting in with the
> usual whines we've heard a zillion times -- Macs cost too much, Python
> is too slow, there's no apps for Macs, Python must absolutely add
> feature X or it will die, Apple's gonna go broke tomorrow, etc, etc --
> do appear to get on our collective nerves worse than their essentially
> indistinguishab le precursors did last year, two years ago, &c.[/color]

I have complained myself about several aspects of Python that I was
discovering as I was learning it (although I never said Python will die).
But I have been programming for enough years to believe that I am entitled
to have an opinion even in something that I am new at and that I am entitled
to express that opinion.

On the other hand, as I become more experienced in Python and I have
opportunities to help other people who are even newer at this than I am, I
also feel some frustration when I do not get enough help from them to help
them. But I probably can still relate better to them because, like them, I
still need help in so many areas.

IMO, we all must show more tolerance. I believe though that newbies are
naturally more tolerant of experts because newbies need the experts. So I
am making a plea particularly to experts to show more tolerance to newbies.
The newbies' complaints come out of frustration, frustration just like
yours, which shows in terms like "clueless", "blasting in", and "whines
we've heard a zillion times", all in just one sentence (and that is in a
discussion on friendliness towards newbies).

Are you learning any new subject now and are you involved in a newsgroup as
a newbie? If you're not doing that already, python experts, please try it
and you'll probably see what it's like. No better way to see the other
side's point of view than being on the other side.

Dan