System configuration#
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#
sizeof(short)
-
NPY_SIZEOF_INT#
sizeof(int)
-
NPY_SIZEOF_LONG#
sizeof(long)
-
NPY_SIZEOF_LONGLONG#
sizeof(longlong) where longlong is defined appropriately on the platform.
-
NPY_SIZEOF_PY_LONG_LONG#
-
NPY_SIZEOF_FLOAT#
sizeof(float)
-
NPY_SIZEOF_DOUBLE#
sizeof(double)
-
NPY_SIZEOF_LONG_DOUBLE#
-
NPY_SIZEOF_LONGDOUBLE#
sizeof(longdouble)
-
NPY_SIZEOF_PY_INTPTR_T#
-
NPY_SIZEOF_INTP#
Size of a pointer on this platform (sizeof(void *))
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.hmacros of GNU Libc. If big endian,NPY_BYTE_ORDER==NPY_BIG_ENDIAN, and similarly for little endian architectures.Defined in
numpy/npy_endian.h.
-
int 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.-
NPY_CPU_BIG#
-
NPY_CPU_LITTLE#
-
NPY_CPU_UNKNOWN_ENDIAN#
-
NPY_CPU_BIG#
Compiler directives#
-
NPY_LIKELY#
-
NPY_UNLIKELY#
-
NPY_UNUSED#