Python Written in C?

[Warren Myers]

Re: Python Written in C?

The OO overheads for C++ are almost non-existent.

http://www.informit.com/articles/article.aspx?p=1192024&ns=15058

On Mon, Jul 21, 2008 at 2:05 PM, Dan Upton <upton@virginia .eduwrote:

On Mon, Jul 21, 2008 at 1:21 PM, Marc 'BlackJack' Rintsch
<bj_666@gmx.net wrote:

>On Mon, 21 Jul 2008 18:12:54 +0200, mk wrote:
>>

>>Seriously, though, would there be any advantage in re-implementing
>>Python in e.g. C++?
>>>
>>Not that current implementation is bad, anything but, but if you're not
>>careful, the fact that lists are implemented as C arrays can bite your
>>rear from time to time (it recently bit mine while using lxml). Suppose
>>C++ re-implementation used some other data structure (like linked list,
>>possibly with twists like having an array containing pointers to 1st
>>linked list elements to speed lookups up), which would be a bit slower
>>on average perhaps, but it would behave better re deletion?

>
Aside (actual reply below): at least for a sorted LL, you're basically
describing Henriksen's algorithm. They can asymptotically be faster,
based on amortized analysis, but they're somewhat more complicated to
implement.
>

>>
>An operation that most people avoid because of the penalty of "shifting
>down" all elements after the deleted one. Pythonistas tend to build new
>lists without unwanted elements instead. I can't even remember when I
>deleted something from a list in the past.
>>
>Ciao,
> Marc 'BlackJack' Rintsch

>
The other side of the equation though is the OO-overhead for C++
programs as compared to C. (A couple years ago we used an
instrumentation tool to check the instruction count for a simple hello
world program written in C (ie, main(){printf(" Hello world!"); return
0;}) and Python (main(){cout<<" hello world"<<endl;re turn 0;}), and the
instruction count was significantly higher for C++. I expect any sort
of C++ objects you used to implement Python structures will be slower
than the equivalent in C. So even if writing it in C++ would reduce
the overhead for deleting from a list, I expect you would lose a lot
more.
--

http://mail.python.org/mailman/listinfo/python-list

>

--

Warren Myers

http://warrenmyers.com

[Tim Rowe]

Re: Python Written in C?

2008/7/21 Krishnakant Mane <hackingkk@gmai l.com>:

First off all c# is absolute rubbish waist of time.

What a pity others are joining in this pointless language flame-war.

Look, I recently had to write a script for manipulating some data; I
struggled to organise it in Python and in C++, but when I tried C#
everything fell naturally into place and I had it done in next to no
time. Other times it has been Python or C++ that has been the most
natural way to express what I'm trying to do. Just because /you/
don't like C# doesn't mean it's rubbish or a waste of time; personally
I loathe Perl, but I respect the fact that a lot of programmers can
get good results very quickly in it.

I reckon that the programmer who only knows one language is like a
carpenter trying to make a cabinet with just a chisel. Ok for making
the joints (although a hammer would have been handy to hit it with),
not /really/ as good as a plane for getting large areas smooth, and
the blade keeps jumping out when you try to use it as a screwdriver...

The one-language programmer isn't really in a position to choose the
right tool for the job, because they only have one tool. Anybody who
says that a language in real use is a waste of time is denying the
reality of those who find it an effective tool. Similarly, anybody who
says that a language -- any language -- is right for all jobs plainly
doesn't understand that language design involves a lot of compromises,
and that the compromises that are appropriate choices for one task are
inappropriate for another. Python is a great tool. So is C#. You /can/
do the same job with either, but the smart move is to choose the one
that is best adapted to the task in hand.

--
Tim Rowe