org.python.util

Class PythonInterpreter

java.lang.Object

org.python.util.PythonInterpreter

All Implemented Interfaces:

Closeable, AutoCloseable

Direct Known Subclasses:

InteractiveInterpreter

public class PythonInterpreter
extends Object
implements AutoCloseable, Closeable

The PythonInterpreter class is a standard wrapper for a Jython interpreter for embedding in a Java application.

Constructor Summary

Constructors

Constructor and Description
PythonInterpreter() Creates a new interpreter with an empty local namespace.
PythonInterpreter(PyObject dict) Creates a new interpreter with a specified local namespace.
PythonInterpreter(PyObject dict, PySystemState systemState)

Method Summary

Methods

Modifier and Type	Method and Description
void	cleanup()
void	close()
PyCode	compile(Reader reader)
PyCode	compile(Reader reader, String filename)
PyCode	compile(String script) Compiles a string of Python source as either an expression (if possible) or a module.
PyCode	compile(String script, String filename)
PyObject	eval(PyObject code) Evaluates a Python code object and returns the result.
PyObject	eval(String s) Evaluates a string as a Python expression and returns the result.
void	exec(PyObject code) Executes a Python code object in the local namespace.
void	exec(String s) Executes a string of Python source in the local namespace.
void	execfile(InputStream s)
void	execfile(InputStream s, String name)
void	execfile(String filename) Executes a file of Python source in the local namespace.
PyObject	get(String name) Returns the value of a variable in the local namespace.
<T> T	get(String name, Class<T> javaclass) Returns the value of a variable in the local namespace.
PyObject	getLocals()
PySystemState	getSystemState()
static void	initialize(Properties preProperties, Properties postProperties, String[] argv) Initializes the Jython runtime.
void	set(String name, Object value) Sets a variable in the local namespace.
void	set(String name, PyObject value) Sets a variable in the local namespace.
void	setErr(OutputStream outStream)
void	setErr(PyObject outStream) Sets a Python object to use for the standard output stream, sys.stderr.
void	setErr(Writer outStream) Sets a Writer to use for the standard output stream, sys.stdout.
void	setIn(InputStream inStream) Sets a InputStream to use for the standard input stream.
void	setIn(PyObject inStream) Sets a Python object to use for the standard input stream, sys.stdin.
void	setIn(Reader inStream) Sets a Reader to use for the standard input stream, sys.stdin.
void	setLocals(PyObject d)
void	setOut(OutputStream outStream) Sets a OutputStream to use for the standard output stream.
void	setOut(PyObject outStream) Sets a Python object to use for the standard output stream, sys.stdout.
void	setOut(Writer outStream) Sets a Writer to use for the standard output stream, sys.stdout.
static PythonInterpreter	threadLocalStateInterpreter(PyObject dict) Creates a new interpreter with the ability to maintain a separate local namespace for each thread (set by invoking setLocals()).

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

PythonInterpreter

public PythonInterpreter()

Creates a new interpreter with an empty local namespace.

PythonInterpreter

public PythonInterpreter(PyObject dict)

Creates a new interpreter with a specified local namespace.

Parameters:

dict - a Python mapping object (e.g., a dictionary) for use as the namespace

PythonInterpreter

public PythonInterpreter(PyObject dict,
                 PySystemState systemState)

Method Detail

initialize

public static void initialize(Properties preProperties,
              Properties postProperties,
              String[] argv)

Initializes the Jython runtime. This should only be called once, before any other Python objects (including PythonInterpreter) are created.

Parameters:

preProperties - A set of properties. Typically System.getProperties() is used. preProperties override properties from the registry file.

postProperties - Another set of properties. Values like python.home, python.path and all other values from the registry files can be added to this property set. postProperties override system properties and registry properties.

argv - Command line arguments, assigned to sys.argv.

threadLocalStateInterpreter

public static PythonInterpreter threadLocalStateInterpreter(PyObject dict)

Creates a new interpreter with the ability to maintain a separate local namespace for each thread (set by invoking setLocals()).

Parameters:

dict - a Python mapping object (e.g., a dictionary) for use as the default namespace

getSystemState

public PySystemState getSystemState()

setIn

public void setIn(PyObject inStream)

Sets a Python object to use for the standard input stream, sys.stdin. This stream is used in a byte-oriented way, through calls to read and readline on the object.

Parameters:

inStream - a Python file-like object to use as the input stream

setIn

public void setIn(Reader inStream)

Sets a Reader to use for the standard input stream, sys.stdin. This stream is wrapped such that characters will be narrowed to bytes. A character greater than U+00FF will raise a Java IllegalArgumentException from within PyString.

Parameters:

inStream - to use as the input stream

setIn

public void setIn(InputStream inStream)

Sets a InputStream to use for the standard input stream.

Parameters:

inStream - InputStream to use as input stream

setOut

public void setOut(PyObject outStream)

Sets a Python object to use for the standard output stream, sys.stdout. This stream is used in a byte-oriented way (mostly) that depends on the type of file-like object. The behaviour as implemented is:

	Python type of object o written
	str/bytes	unicode	Any other type
PyFile	as bytes directly	respect PyFile.encoding	call str(o) first
PyFileWriter	each byte value as a char	write as Java chars	call o.toString() first
Other PyObject f	invoke f.write(str(o))	invoke f.write(o)	invoke f.write(str(o))

Parameters:

outStream - Python file-like object to use as the output stream

setOut

public void setOut(Writer outStream)

Sets a Writer to use for the standard output stream, sys.stdout. The behaviour as implemented is to output each object o by calling o.toString() and writing this as UTF-16.

Parameters:

outStream - to use as the output stream

setOut

public void setOut(OutputStream outStream)

Sets a OutputStream to use for the standard output stream.

Parameters:

outStream - OutputStream to use as output stream

setErr

public void setErr(PyObject outStream)

Sets a Python object to use for the standard output stream, sys.stderr. This stream is used in a byte-oriented way (mostly) that depends on the type of file-like object, in the same way as setOut(PyObject).

Parameters:

outStream - Python file-like object to use as the error output stream

setErr

public void setErr(Writer outStream)

Sets a Writer to use for the standard output stream, sys.stdout. The behaviour as implemented is to output each object o by calling o.toString() and writing this as UTF-16.

Parameters:

outStream - to use as the error output stream

setErr

public void setErr(OutputStream outStream)

eval

public PyObject eval(String s)

Evaluates a string as a Python expression and returns the result.

eval

public PyObject eval(PyObject code)

Evaluates a Python code object and returns the result.

exec

public void exec(String s)

Executes a string of Python source in the local namespace.

exec

public void exec(PyObject code)

Executes a Python code object in the local namespace.

execfile

public void execfile(String filename)

Executes a file of Python source in the local namespace.

execfile

public void execfile(InputStream s)

execfile

public void execfile(InputStream s,
            String name)

compile

public PyCode compile(String script)

Compiles a string of Python source as either an expression (if possible) or a module. Designed for use by a JSR 223 implementation: "the Scripting API does not distinguish between scripts which return values and those which do not, nor do they make the corresponding distinction between evaluating or executing objects." (SCR.4.2.1)

compile

public PyCode compile(Reader reader)

compile

public PyCode compile(String script,
             String filename)

compile

public PyCode compile(Reader reader,
             String filename)

getLocals

public PyObject getLocals()

setLocals

public void setLocals(PyObject d)

set

public void set(String name,
       Object value)

Sets a variable in the local namespace.

Parameters:

name - the name of the variable

value - the object to set the variable to (as converted to an appropriate Python object)

set

public void set(String name,
       PyObject value)

Sets a variable in the local namespace.

Parameters:

name - the name of the variable

value - the Python object to set the variable to

get

public PyObject get(String name)

Returns the value of a variable in the local namespace.

Parameters:

name - the name of the variable

Returns:

the value of the variable, or null if that name isn't assigned

get

public <T> T get(String name,
        Class<T> javaclass)

Returns the value of a variable in the local namespace. The value will be returned as an instance of the given Java class. interp.get("foo", Object.class) will return the most appropriate generic Java object.

Parameters:

name - the name of the variable

javaclass - the class of object to return

Returns:

the value of the variable as the given class, or null if that name isn't assigned

cleanup

public void cleanup()

close

public void close()

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable