When NumPy is built, information about system configuration is recorded, and is made available for extension modules using Numpy?s C API. These are mostly defined in numpyconfig.h
(included in ndarrayobject.h
). The public symbols are prefixed by NPY_*
. Numpy also offers some functions for querying information about the platform in use.
For private use, Numpy also constructs a config.h
in the NumPy include directory, which is not exported by Numpy (that is a python extension which use the numpy C API will not see those symbols), to avoid namespace pollution.
Data type sizes
The NPY_SIZEOF_{CTYPE}
constants are defined so that sizeof information is available to the pre-processor.
-
NPY_SIZEOF_SHORT
-
NPY_SIZEOF_INT
-
NPY_SIZEOF_LONG
-
NPY_SIZEOF_LONGLONG
-
sizeof(longlong) where longlong is defined appropriately on the platform.
-
NPY_SIZEOF_PY_LONG_LONG
-
NPY_SIZEOF_FLOAT
-
NPY_SIZEOF_DOUBLE
-
NPY_SIZEOF_LONG_DOUBLE
-
NPY_SIZEOF_PY_INTPTR_T
-
Size of a pointer on this platform (sizeof(void *)) (A macro defines NPY_SIZEOF_INTP as well.)
Platform information
-
NPY_CPU_X86
-
NPY_CPU_AMD64
-
NPY_CPU_IA64
-
NPY_CPU_PPC
-
NPY_CPU_PPC64
-
NPY_CPU_SPARC
-
NPY_CPU_SPARC64
-
NPY_CPU_S390
-
NPY_CPU_PARISC
-
New in version 1.3.0.
CPU architecture of the platform; only one of the above is defined.
Defined in
numpy/npy_cpu.h
-
NPY_LITTLE_ENDIAN
-
NPY_BIG_ENDIAN
-
NPY_BYTE_ORDER
-
New in version 1.3.0.
Portable alternatives to the
endian.h
macros of GNU Libc. If big endian,NPY_BYTE_ORDER
==NPY_BIG_ENDIAN
, and similarly for little endian architectures.Defined in
numpy/npy_endian.h
.
-
PyArray_GetEndianness()
-
New in version 1.3.0.
Returns the endianness of the current platform. One of
NPY_CPU_BIG
,NPY_CPU_LITTLE
, orNPY_CPU_UNKNOWN_ENDIAN
.
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