`scipy._lib._ccallback:LowLevelCallable`

source: /scipy/_lib/_ccallback.py :26

Signature

class LowLevelCallable ( function , user_data = None , signature = None )

Members

Summary

Low-level callback function.

Extended Summary

Some functions in SciPy take as arguments callback functions, which can either be python callables or low-level compiled functions. Using compiled callback functions can improve performance somewhat by avoiding wrapping data in Python objects.

Such low-level functions in SciPy are wrapped in LowLevelCallable objects, which can be constructed from function pointers obtained from ctypes, cffi, Cython, or contained in Python PyCapsule objects.

Parameters

function : {PyCapsule, ctypes function pointer, cffi function pointer}: Low-level callback function.
user_data : {PyCapsule, ctypes void pointer, cffi void pointer}: User data to pass on to the callback function.
signature : str, optional: Signature of the function. If omitted, determined from function, if possible.

Attributes

function: Callback function given.
user_data: User data given.
signature: Signature of the function.

Methods

from_cython: Class method for constructing callables from Cython C-exported functions.

Notes

The argument function can be one of:

PyCapsule, whose name contains the C function signature
ctypes function pointer
cffi function pointer

The signature of the low-level callback must match one of those expected by the routine it is passed to.

If constructing low-level functions from a PyCapsule, the name of the capsule must be the corresponding signature, in the format

return_type (arg1_type, arg2_type, ...)

For example

"void (double)"
"double (double, int *, void *)"

The context of a PyCapsule passed in as function is used as user_data, if an explicit value for user_data was not given.

Aliases

scipy.LowLevelCallable