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Re: [Jython-users] Jython Caching Argv
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From: Jeff A. <ja...@fa...> - 2018-08-13 17:50:21
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Deb: You could try building your JAR from the contents extracted from the Jython standalone JAR. Most build tools can treat a JAR as a source in this way. e.g. Ant: https://stackoverflow.com/a/185116 , or Gradle: https://docs.gradle.org/current/userguide/working_with_files.html#sec:creating_uber_jar_example . In my example, argv is a reference to a PyList. This has an API by which you could add/remove items without setting sys.argv. It may be clearer like this: PySystemState sys = pyInterpreter.getSystemState(); sys.argv.__add__(Py.newString("hello")); sys.argv.__add__(Py.newString("world")); Although I think you could safely make a new PyList and replace it if you wanted: sys.argv = new PyList() Jeff Allen On 13/08/2018 09:53, Debashish wrote: > 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... > <mailto: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... >> <mailto: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... <mailto: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... >> <mailto: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 >> <http://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... >> <mailto: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... >> <mailto: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... >> <mailto:Jyt...@li...> >> https://lists.sourceforge.net/lists/listinfo/jython-users >> > |
