PythonInterpreter (Jython API documentation)

java.lang.Object
- org.python.util.PythonInterpreter

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable

Direct Known Subclasses:

InteractiveInterpreter
```
public class PythonInterpreter
extends java.lang.Object
implements java.lang.AutoCloseable, java.io.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

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`cleanup()`
`void`	`close()`
`PyCode`	`compile(java.io.Reader reader)`
`PyCode`	`compile(java.io.Reader reader, java.lang.String filename)`
`PyCode`	`compile(java.lang.String script)` Compiles a string of Python source as either an expression (if possible) or a module.
`PyCode`	`compile(java.lang.String script, java.lang.String filename)`
`PyObject`	`eval(PyObject code)` Evaluates a Python code object and returns the result.
`PyObject`	`eval(java.lang.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(java.lang.String s)` Executes a string of Python source in the local namespace.
`void`	`execfile(java.io.InputStream s)`
`void`	`execfile(java.io.InputStream s, java.lang.String name)`
`void`	`execfile(java.lang.String filename)` Executes a file of Python source in the local namespace.
`PyObject`	`get(java.lang.String name)` Returns the value of a variable in the local namespace.
`<T> T`	`get(java.lang.String name, java.lang.Class<T> javaclass)` Returns the value of a variable in the local namespace.
`PyObject`	`getLocals()`
`PySystemState`	`getSystemState()`
`static void`	`initialize(java.util.Properties preProperties, java.util.Properties postProperties, java.lang.String[] argv)` Initializes the Jython runtime.
`void`	`set(java.lang.String name, java.lang.Object value)` Sets a variable in the local namespace.
`void`	`set(java.lang.String name, PyObject value)` Sets a variable in the local namespace.
`void`	`setErr(java.io.OutputStream outStream)`
`void`	`setErr(PyObject outStream)` Sets a Python object to use for the standard output stream, `sys.stderr`.
`void`	`setErr(java.io.Writer outStream)` Sets a `Writer` to use for the standard output stream, `sys.stdout`.
`void`	`setIn(java.io.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(java.io.Reader inStream)` Sets a `Reader` to use for the standard input stream, `sys.stdin`.
`void`	`setLocals(PyObject d)`
`void`	`setOut(java.io.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(java.io.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(java.util.Properties preProperties,
                              java.util.Properties postProperties,
                              java.lang.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(java.io.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(java.io.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:

Stream behaviour for various object types
	`str/bytes`	`unicode`	Any other type
	Python type of object `o` written
`PyFile`	as bytes directly	respect `PyFile.encoding`	call `str(o)` first
`PyFileWriter`	each byte value as a `char`	write as Java `char`s	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(java.io.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(java.io.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(java.io.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(java.io.OutputStream outStream)

eval
```
public PyObject eval(java.lang.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(java.lang.String s)
```
Executes a string of Python source in the local namespace. In some environments, such as Windows, Unicode characters in the script will be converted into ascii question marks (?). This can be avoided by first compiling the fragment using PythonInterpreter.compile(), and using the overridden form of this method which takes a PyCode object. Code page declarations are not supported.

exec
```
public void exec(PyObject code)
```
Executes a Python code object in the local namespace.

execfile
```
public void execfile(java.lang.String filename)
```
Executes a file of Python source in the local namespace.

execfile

public void execfile(java.io.InputStream s)

execfile

public void execfile(java.io.InputStream s,
                     java.lang.String name)

compile
```
public PyCode compile(java.lang.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(java.io.Reader reader)

compile

public PyCode compile(java.lang.String script,
                      java.lang.String filename)

compile

public PyCode compile(java.io.Reader reader,
                      java.lang.String filename)

getLocals
```
public PyObject getLocals()
```

setLocals
```
public void setLocals(PyObject d)
```

set
```
public void set(java.lang.String name,
                java.lang.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(java.lang.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(java.lang.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(java.lang.String name,
                 java.lang.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 java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Class PythonInterpreter

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

PythonInterpreter

PythonInterpreter

PythonInterpreter

Method Detail

initialize

threadLocalStateInterpreter

getSystemState

setIn

setIn

setIn

setOut

setOut

setOut

setErr

setErr

setErr

eval

eval

exec

exec

execfile

execfile

execfile

compile

compile

compile

compile

getLocals

setLocals

set

set

get

get

cleanup

close