Package org.bytedeco.embeddedpython

Class Python

java.lang.Object

org.bytedeco.embeddedpython.Python

public class Python
extends Object

Python interpreter.

If you embed two Python interpreters, many Python libraries do not work correctly. Therefore this class is a singleton class. All the methods are static.

This class is thread-safe. All the methods are synchronized.

Method Summary

Modifier and Type	Method	Description
static <T> T	eval(String src)	Python built-in eval().
static void	exec(String src)	Python built-in exec().
static <T> T	get(String name)	Get the global Python variable and convert it to a Java object.
static void	put(String name, Object value)	Convert the Java object and set it to the global Python variable.

Methods inherited from class java.lang.Object

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

Method Detail

eval

public static <T> T eval(String src)

Python built-in eval().

Type Parameters:

T - The Java class after conversion from Python.

Parameters:

src - Python code. This must be a single line code.

Returns:

The Java object converted from the Python object.

exec

public static void exec(String src)

Python built-in exec().

Parameters:

src - Python code. This can be multiple lines code.

get

public static <T> T get(String name)

Get the global Python variable and convert it to a Java object.

Type mappings. Python to Java.

Python	Java
None	null
bool	boolean
int	long
float	double
str	String
scalar np.bool8	boolean
scalar np.int8	byte
scalar np.int16	short
scalar np.uint16	char
scalar np.int32	int
scalar np.int64	long
scalar np.float32	float
scalar np.float64	double
scalar np.datetime64[W, D, h, m, s, ms, us, or ns]	Instant
bytes	byte[]
bytearray	byte[]
dict	LinkedHashMap
ndarray np.bool8	NpNdarrayBoolean
ndarray np.int8	NpNdarrayByte
ndarray np.int16	NpNdarrayShort
ndarray np.uint16	NpNdarrayChar
ndarray np.int32	NpNdarrayInt
ndarray np.int64	NpNdarrayLong
ndarray np.float32	NpNdarrayFloat
ndarray np.float64	NpNdarrayDouble
ndarray np.datetime64[W, D, h, m, s, ms, us, or ns]	NpNdarrayInstant
iterable	ArrayList

Type Parameters:

T - The Java class after conversion from Python.

Parameters:

name - The variable name

Returns:

The Java object converted from the Python object.

Throws:

PythonException - If the value cannot convert to a Java object.

NoSuchElementException - If the variable does not exists.

put

public static void put(String name,
                       Object value)

Convert the Java object and set it to the global Python variable.

Type mappings. Java to Python.

Java	Python
null	None
boolean	bool
byte	int
short	int
char	int
int	int
long	int
float	float
double	float
Instant	np.datetime64[ns]
String	str
byte[]	bytes
boolean[]	np.ndarray, dtype=np.bool8
short[]	np.ndarray, dtype=np.int16
char[]	np.ndarray, dtype=np.uint16
int[]	np.ndarray, dtype=np.int32
long[]	np.ndarray, dtype=np.int64
float[]	np.ndarray, dtype=np.float32
double[]	np.ndarray, dtype=np.float64
Instant[]	np.ndarray, dtype=np.datetime64[ns]
NpNdarrayBoolean	np.ndarray, dtype=np.bool8
NpNdarrayByte	np.ndarray, dtype=np.int8
NpNdarrayShort	np.ndarray, dtype=np.int16
NpNdarrayChar	np.ndarray, dtype=np.uint16
NpNdarrayInt	np.ndarray, dtype=np.int32
NpNdarrayLong	np.ndarray, dtype=np.int64
NpNdarrayFloat	np.ndarray, dtype=np.float32
NpNdarrayDouble	np.ndarray, dtype=np.float64
NpNdarrayInstant	np.ndarray, dtype=np.datetime64[ns]
java.util.Map	dict
scala.collection.Map	dict
Object[]	list
Iterable	list
scala.Function0 - Function22	built-in global Python function

Parameters:

name - The variable name

value - The value to put.

Throws:

PythonException - If the value cannot convert to a Python object.