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 Details

    • 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 Details

    • 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:
      Stream behaviour for various object types
      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. 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(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 AutoCloseable
      Specified by:
      close in interface Closeable