On Tue, 28 Sep 2010 11:56:33 am Alex Hall wrote: > > (But don't forget that Python is not necessarily written in C. > > There's Jython, written in Java, and CLPython written in Lisp, and > > many others. How they implement objects may be different. What > > happens under the hood isn't important, so long as the behaviour at > > the Python level remains the same.) > > Really? Neat! I wonder what the advantage of doing that is, since the > end result, as you say, should be the same once you start writing > Python code?
Different implementations can make different choices, to suit different needs. So long as the end result is the same, they can choose different mechanisms, different techniques, radically different strategies, or simply choose a different implementation language because they can. CPython is a conservative implementation written in ordinary C so that it is available on almost any platform that has a C compiler. Efficiency is not its primary goal, clarity of code and simplicity of design is considered just as important. This is almost certainly the version you are using. Unladen Swallow is a version of CPython written by Google that aims to speed up certain time-critical parts. If it works, it may end up being merged with the regular CPython. Unfortunately, after a flash of publicity and some promising early results, Unladen Swallow seems to have gone quiet. PyPy is a version of Python written in Python. It has an incredible mission: to eventually produce versions of Python which are faster than pure C, despite being written in Python itself. Although they have a long, long way to go, they are making good progress, and PyPy can now run Python code faster than CPython. PyPy is becoming a generalised Just-In-Time compiler for high-level languages like Python. IronPython and Jython are designed to integrate with Dot-Net and Java. IronPython is probably written in C#, like most Dot-Net software, and Jython is written in Java. Stackless Python is similar to CPython except it doesn't have a function call stack, which is good for certain specialist applications. Pynie is an experimental version of Python written for the Parrot virtual machine used by Perl 6. CapPython is a restricted version of Python which aims to be much more secure, allowing you to safely run untrusted code without it eating your computer. And there are many more... I count at least 41 current or past Python implementations, add-ons and related projects. My favourite (apart from PyPy, which makes me feel all warm and tingly in that special place) is LikePython: http://www.staringispolite.com/likepython/ #!usr/bin/python # My first Like, Python script! yo just print like "hello world" bro I can't wait to put that on my resume :) -- Steven D'Aprano _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
