Another scripting language implemented into Python itself?

[Jeff Shannon]

Roy Smith wrote:

> In article <mailman.1231.1106610969.22381.python-list at python.org>,
>  Quest Master <zainalam at gmail.com> wrote:
> 
>>So, my question is simply this: is there an implementation of another
>>scripting language into Python?
> 
> Python *is* a scripting language.  Why not just let your users write 
> Python modules which you them import and execute via some defined API?

Because you cannot make Python secure against a malicious (or 
ignorant) user -- there's too much flexibility to be able to guard 
against every possible way in which user-code could harm the system. 
Parsing your own (limited) scripting language allows much better 
control over what user-code is capable of doing, and therefore allows 
(at least some measure of) security against malicious code.

To the O.P.:  Yes, people have implemented other languages in Python. 
  For example, I believe that Danny Yoo has written a Scheme 
interpreter in Python (Google tells me it should be at 
http://hkn.eecs.berkeley.edu/~dyoo/python/pyscheme but I'm getting no 
response from that host right now), but I don't know whether Scheme 
counts as a scripting language. ;)

However, if you're using a fully-featured language for these user 
scripts, you'll probably have the same security issues I mentioned for 
Python.  Unless you really need that level of features, you may be 
better off designing your own limited language.  Check into the docs 
for pyparsing for a starter...

Jeff Shannon
Technician/Programmer
Credit International