text analysis in python

[Steve Holden]

Maurice LING wrote:
> Terry Reedy wrote:
> 
>> "Maurice LING" <mauriceling at acm.org> wrote in message 
>> news:424FF1CD.2040102 at acm.org...
>>
>>> Say I code my  stuffs in Jython (importing java libraries) in a file 
>>> "text.py"
>>
>>
>>
>> Just to be clear, Jython is not a separate langague that you code 
>> *in*, but a separate implementation that you may slightly differently 
>> code *for*.
>>
> Yes, I do get this point rightly. Jython is just an implementation of 
> Python virtual machine using Java. I do note that there are some 
> differences, such as, Jython can only handle pure python modules. 
> However, I'm not a language expert to differentiate language differences 
> between these 2 implementations of Python, as in Jython and CPython. If 
> someone care to enlighten, it will be my pleasure to consult. TIA.
> 
That's not strictly correct. The Python virtual machine isn;t 
implemented at all in Jython, instead the JVM is used as the compilation 
target.

>>
>>> ... Will there be any issues when I try to import text.py into CPython?
>>
>>
>>
>> If text.py is written in an appropriate version of Python, it itself 
>> will cause no problem.  Hoqwever, when it imports javacode files, as 
>> opposed to CPython bytecode files, CPython will choke.
>>
> In my example, the file "text.py" is coded in Jython, importing Java 
> libraries. I do get that I cannot import Java jar files directly into 
> CPython. What I do not get is that what is so special about Jython that 
> it can "fool" CPython into using Java libraries... or is that there will 
> always be a need for Java virtual machine and Python virtual machine 
> when I use Java libraries in Jython... and importing Jython coded files 
> into CPython....
> 
Jython is pretty much a Python interpreter that compiles Python into JVM 
bytecodes. Consequently the amount of "trickery" involved is rather 
less, though clearly there is some (automated conversion b etween Java 
and Pythin data types where appropriate, and automated signature-based 
selection of the appropriate Java method being the two most obvious).

regards
  Steve
-- 
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