Python Nelson types

Managing Data between Python and Nelson.

Description

Managing data returned by Python functions:

Python return type, as shown in Python	Corresponding Nelson type (scalar)
bool	logical
complex	double (complex)
float	double

Convert Python types to Nelson type explicitly:

Python return types or protocols shown in Nelson	Nelson conversion methods
py.str	char, string
py.int	double, single, int8, uint8, int16, uint16, int32, uint32, int64, uint64
py.long	double, single, int8, uint8, int16, uint16, int32, uint32, int64, uint64
py.float	double, single, int8, uint8, int16, uint16, int32, uint32, int64, uint64
py.bool	double, single, int8, uint8, int16, uint16, int32, uint32, int64, uint64, logical
py.bytes	double, single, int8, uint8, int16, uint16, int32, uint32, int64, uint64, logical
py.bytearray	double, single, int8, uint8, int16, uint16, int32, uint32, int64, uint64, logical
py.array.array	double, single, int8, uint8, int16, uint16, int32, uint32, int64, uint64
py.memoryview	double, single, int8, uint8, int16, uint16, int32, uint32, int64, uint64
py.numpy.ndarray	double, single, int8, uint8, int16, uint16, int32, uint32, int64, uint64
py.list	double, single, int8, uint8, int16, uint16, int32, uint32, int64, uint64, logical, string, cell
py.tuple	double, single, int8, uint8, int16, uint16, int32, uint32, int64, uint64, logical, string, cell
py.dict	struct

Pass scalar Nelson type to Python:

Nelson scalar input argument type	Python type
NaN	float("nan")
Inf	float("inf")
double (real)	py.float
single (real)	py.float
double (complex)	py.complex
single (complex)	py.complex
int8	py.int
uint8	py.int
int16	py.int
uint16	py.int
int32	py.int
uint32	py.int
int64	py.int
uint64	py.int
string scalar	py.str
char vector	py.str
logical	py.bool
struct	py.dict

Pass 1-by-N Vector Nelson type to Python:

Nelson 1-by-N Vector input argument type	Python type
double (real)	array.array('d')
single (real)	array.array('f')
int8	array.array('b')
uint8	array.array('B')
int16	array.array('h')
uint16	array.array('H')
int32	array.array('i')
uint32	array.array('I')
int64	array.array('q')
uint64	array.array('Q')
double	memoryview
single	memoryview
logical	memoryview
char vector	str
string scalar	str
cell vector	tuple

Pass 2D Matrices and ND Arrays to Python:

The Python language offers a protocol for accessing memory buffers, akin to the data stored in Nelson arrays.

Nelson incorporates this Python buffer protocol for its arrays.

Examples

R = pyrun('', "A", 'A', magic(3))
R.double()

dictionary conversion nelson -- python

wheels = [1 2 3];
names = ["Monocycle" "Bicycle" "Tricycle"];
d = dictionary(wheels, names)
R = pyrun("A = d", "A", 'd', d)
dictionary(R)

See also

pyrun, dictionary.

History

Version	Description
1.4.0	initial version

Author

Allan CORNET