Menu
▾
▴
Re: [Jython-users] Jython Caching Argv
|
From: Debashish <deb...@gm...> - 2018-08-13 08:54:37
|
Hi Jeff,
Sorry but my requirement is not to run the Jython standalone JAR. The
Jython JAR will be packaged (along with other dependency JARs) inside my
application JAR and I have to run this application JAR. This is my primary
pain point, that there is no obvious way to specify the Jythin library
files to the running application, even after putting Jythin JAR on
classpath. Here I have no way to supply an absolute, file system path to
the library.
Also I am not sure I understand how we can manipulaet the argv we get from:
PyList argv = pyInterpreter.getSystemState().argv;
I see no setter method inside pyInterpreter to set the modified argv back.
Thanks,
Deb
On Sun, 12 Aug 2018 at 18:41, Jeff Allen <ja...@fa...> wrote:
> Hi Deb:
>
> By CPython I mean the implementation of the Python language written in C,
> which is the one most people mean when they just say "Python".
>
> Do not put the copy of the standard library that comes with CPython on the
> path for Jython. It may seem to work, but then bizarre things start to
> happen and no-one can help you. Jython has its own copy with many small
> adaptations, which (for you) is in the standalone JAR and need not be
> extracted.
>
> You probably don't need python.home. It is as easy as this to run Jython
> (in an empty directory that I just created):
>
> PS here> java -cp "C:\Jython\2.7.1-sa\jython-standalone-2.7.1.jar" org.python.util.jython
> Jython 2.7.1 (default:0df7adb1b397, Jun 30 2017, 19:02:43)
> [Java HotSpot(TM) 64-Bit Server VM (Oracle Corporation)] on java1.7.0_60
> Type "help", "copyright", "credits" or "license" for more information.
> >>> import sys, colorsys
> >>> sys.path
> ['', 'C:\\Jython\\2.7.1-sa\\Lib', 'C:\\Jython\\2.7.1-sa\\jython-standalone-2.7.1.jar\\Lib', '__classpath__', '__pyclasspath__/', 'C:\\Users\\Jeff\\.local\\lib\\jython2.7\\site-packages']
>
> I'm not sure why we have the second entry as well as the third on the path
> in this case as the library is in the JAR:
>
> >>> colorsys.__file__
> 'C:\\Jython\\2.7.1-sa\\*jython-standalone-2.7.1.jar**\\Lib\\*colorsys.py'
> >>> exit()
>
> Now, if I define python.home to a folder that contains an alternate
> library:
>
> PS here> java "-Dpython.home=..\271-sa" -cp "C:\Jython\2.7.1-sa\jython-standalone-2.7.1.jar" org.python.util.jython
> Jython 2.7.1 (default:0df7adb1b397, Jun 30 2017, 19:02:43)
> [Java HotSpot(TM) 64-Bit Server VM (Oracle Corporation)] on java1.7.0_60
> Type "help", "copyright", "credits" or "license" for more information.
> >>> import sys, colorsys
> >>> sys.path
> ['', 'C:\\Users\\Jeff\\Documents\\Jython\\271-sa\\Lib', 'C:\\Jython\\2.7.1-sa\\jython-standalone-2.7.1.jar\\Lib', '__classpath__', '__pyclasspath__/', 'C:\\Users\\Jeff\\.local\\lib\\jython2.7\\site-packages', 'C:\\Users\\Jeff\\Documents\\Jython\\271-sa\\Lib\\site-packages']
> >>> colorsys.__file__
> 'C:\\Users\\Jeff\\Documents\\Jython\\271-sa\\Lib\\colorsys.py'
>
> You see that Jython has looked there first and found the colorsys module.
>
> It's always worth exploring Python at the prompt first, but I'm aware you
> want to call interpreters from Java. I'm pretty sure argv is just:
>
>
> PyList argv = pyInterpreter.getSystemState().argv;
>
> This will be a copy of the default you supplied, that you can manipulate
> as you wish.
>
> Jeff
>
> Jeff Allen
>
> On 12/08/2018 10:53, Debashish wrote:
>
> Sorry, I got confused by the term CPython, I guess if I have Python
> installed its already CPython that I am using :) So the first bullet in my
> reply should only read that "Indeed I set *python.home* to my local
> CPython installation". And that worked (somehow).
>
> On Sun, 12 Aug 2018 at 15:11, Debashish <deb...@gm...> wrote:
>
>> Hi Jeff, Adam,
>>
>> Thanks a ton for the prompt reply. Few clarifications:
>>
>> 1. The *python.home* path I gave is the *local* Python 2.7
>> installation path. I assume you are saying this should be *CPython*
>> home rather. I will try this after installing CPython locally.
>> 2. The problem is that I wish to deploy my code on Pivotal Cloud
>> Foundry (PCF) where I would not be able to install anything else apart from
>> the application JAR, no file-system access is available as since the code
>> runs inside PCF containers, I cannot expect Python or CPython to be
>> installed on that system.
>> 3. I tried several thing to make it work (for e.g. extracted the *Lib*
>> folder from the JAR and added it on the classpath, also renamed the JAR to
>> *jython.jar* and added it to classpath, supplied the Lib folder path
>> as *python.path* as well), none of these worked. It seems if there is
>> no way to supply the absolute path, then there is no way to make it work
>> from within a Java JAR.
>> 4. My Python script is current 400 LOCs and will keep on growing, so
>> I cannot possibly call its *functions* from my Java code as it would
>> couple it to the Python code. I guess the only better option would be to
>> port this Python code to Java.
>> 5. I am using Jython Standalone JAR 2.7.1 from Maven central. I think
>> what you are saying is that instead of passing command line arguments
>> (argv) to the static *initialize* method I can pass it to the
>> *PythonInterpreter* object rather. I am not sure how, as I do not
>> such any such method in the API. Is there a code example available?
>>
>> Thanks again for your help.
>>
>> Deb
>>
>> On Sun, 12 Aug 2018 at 03:26, Adam Burke <ada...@gm...> wrote:
>>
>>> Hi Deb
>>>
>>> On top of that, depending on how the script you’re calling is written,
>>> it might be useful to call one layer down instead of using I/O. Jython lets
>>> you work with python objects fairly directly from Java, and call Python
>>> functions directly as well. So if your python script has internal functions
>>> and classes, you could call straight into them.
>>>
>>> YMMV.
>>>
>>> Adam
>>>
>>> > 在 2018年8月12日，上午7:41，Jeff Allen <ja...@fa...> 写道：
>>> >
>>> > I don't know anything about Spring Boot, but the standalone JAR must
>>> be on your path for you to be able to refer to "PythonInterpreter" in your
>>> code. So by "not detected" I guess you mean that Jython appear not to find
>>> its library (which is in the standalone JAR). Jython guesses based on the
>>> path to the JAR it seems to be running from (that org.python.core.Py
>>> was loaded from) but telling it is safer.
>>> >
>>> > This bit struck me as odd:
>>> >
>>> > props.put("python.home", "C:\\Dev\\Python27");
>>> >
>>> > That's not the location of CPython is it? That would cause you a world
>>> of confusion.
>>> >
>>> > However, none of that addresses your question about argv (meaning
>>> sys.argv I suppose). The important observation here is that
>>> "PythonInterpreter.initialize" is a static method that sets a default argv
>>> that all interpreters will see as they are created. It makes a big
>>> difference now what version you are using. In 2.7.0, all interpreters were
>>> really the same interpreter: you got a separate namespace for your main,
>>> but the modules where all the same, in particular every interpreter shared
>>> sys. In 2.7.1, each interpreter gets its own sys, and so each module used
>>> is loaded again for each interpreter.
>>> >
>>> > I cannot say off the top of my head what the behaviour of the default
>>> argv and sys.argv is, but I'm pretty sure the interpreter you make in the
>>> next line has its own sys and the sys.argv you could set independently,
>>> although not in the constructor.
>>> >
>>> > Jeff Allen
>>> >
>>> >> On 11/08/2018 20:16, Debashish wrote:
>>> >> Hi,
>>> >>
>>> >> I am trying to call a Python Script from a Spring Boot applications.
>>> There are two issues I am facing:
>>> >> (1) The Jython Standalone JAR is not detected and I am forced to
>>> supply the local install path as "python.home" to make it work.
>>> >> (2) Once I initialize the /PythonInterpreter/ class, it seems it
>>> caches the argv I supply to it as for the subsequent invocation it uses the
>>> same argv values. I do call the close() method to do cleanup, but it
>>> doesn't help :(
>>> >>
>>> >> Properties preprops = System.getProperties();
>>> >> Properties props = new Properties();
>>> >>
>>> >> props.put("python.home", "C:\\Dev\\Python27");
>>> >> props.put("python.console.encoding", "UTF-8");
>>> >> props.put("python.security.respectJavaAccessibility", "false");
>>> >> props.put("python.import.site", "false");
>>> >>
>>> >> PythonInterpreter.initialize(preprops, props, arguments);
>>> >> PythonInterpreter pyInterpreter = new PythonInterpreter();
>>> >>
>>> >> try {
>>> >> resource = new ClassPathResource("mypyscript.py");
>>> >> out = new ByteArrayOutputStream();
>>> >> err = new ByteArrayOutputStream();
>>> >> pyInterpreter.setOut(out);
>>> >> pyInterpreter.setErr(err);
>>> >> pyInterpreter.execfile(resource.getInputStream());
>>> >> result[0] = out.toString(); // reading the output
>>> >> result[1] = err.toString(); // reading any error
>>> >> } catch (Exception e) {
>>> >> throw new Exception(e);
>>> >> } finally {
>>> >> try {
>>> >> if (out != null)
>>> >> out.close();
>>> >> if (err != null)
>>> >> err.close();
>>> >> pyInterpreter.close();
>>> >> } catch (IOException e) {
>>> >> e.printStackTrace();
>>> >> }
>>> >> }
>>> >>
>>> >> Please help.
>>> >>
>>> >> Thanks,
>>> >>
>>> >> Deb
>>> >>
>>> >>
>>> >>
>>> ------------------------------------------------------------------------------
>>> >> Check out the vibrant tech community on one of the world's most
>>> >> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
>>> >>
>>> >>
>>> >> _______________________________________________
>>> >> Jython-users mailing list
>>> >> Jyt...@li...
>>> >> https://lists.sourceforge.net/lists/listinfo/jython-users
>>> >
>>> >
>>> >
>>> ------------------------------------------------------------------------------
>>> > Check out the vibrant tech community on one of the world's most
>>> > engaging tech sites, Slashdot.org! http://sdm.link/slashdot
>>> > _______________________________________________
>>> > Jython-users mailing list
>>> > Jyt...@li...
>>> > https://lists.sourceforge.net/lists/listinfo/jython-users
>>>
>>>
>>> ------------------------------------------------------------------------------
>>> Check out the vibrant tech community on one of the world's most
>>> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
>>> _______________________________________________
>>> Jython-users mailing list
>>> Jyt...@li...
>>> https://lists.sourceforge.net/lists/listinfo/jython-users
>>>
>>
>
|
