Python’s complex number objects are implemented as two distinct types when viewed from the C API: one is the Python object exposed to Python programs, and the other is a C structure which represents the actual complex number value. The API provides functions for working with both.
Complex Numbers as C Structures
Note that the functions which accept these structures as parameters and return them as results do so by value rather than dereferencing them through pointers. This is consistent throughout the API.
typePy_complex
The C structure which corresponds to the value portion of a Python complex number object. Most of the functions for dealing with complex number objects use structures of this type as input or output values, as appropriate.
doublereal
doubleimag
The structure is defined as:
typedefstruct{doublereal;doubleimag;}Py_complex;
_Py_c_sum(
left,
right)
Return the sum of two complex numbers, using the C
representation.
_Py_c_diff(
left,
right)
Return the difference between two complex numbers, using the C
representation.
_Py_c_neg(
num)
Return the negation of the complex number num, using the C
representation.
_Py_c_prod(
left,
right)
Return the product of two complex numbers, using the C
representation.
_Py_c_quot(
dividend,
divisor)
Return the quotient of two complex numbers, using the C
representation.
If divisor is null, this method returns zero and sets errno to EDOM.
_Py_c_pow(
num,
exp)
Return the exponentiation of num by exp, using the C
representation.
If num is null and exp is not a positive real number, this method returns zero and sets errno to EDOM.
Set errno to ERANGE on overflows.
Complex Numbers as Python Objects
typePyComplexObject
This subtype of
represents a Python complex number object.
PyComplex_Type
Part of the
.This instance of
represents the Python complex number type. It is the same object as
in the Python layer.
intPyComplex_Check(
*p)
Return true if its argument is a
or a subtype of PyComplexObject. This function always succeeds.
intPyComplex_CheckExact(
*p)
Return true if its argument is a
, but not a subtype of PyComplexObject. This function always succeeds.
*PyComplex_FromCComplex(
v)
Return value: New reference.Create a new Python complex number object from a C
value. Return NULL with an exception set on error.
*PyComplex_FromDoubles(doublereal, doubleimag)
Return value: New reference. Part of the
.Return a new
object from real and imag. Return NULL with an exception set on error.
doublePyComplex_RealAsDouble(
*op)
Part of the
.Return the real part of op as a C double.
If op is not a Python complex number object but has a
method, this method will first be called to convert op to a Python complex number object. If __complex__() is not defined then it falls back to call
and returns its result.
Upon failure, this method returns -1.0 with an exception set, so one should call
to check for errors.
Changed in version 3.13: Use
if available.
doublePyComplex_ImagAsDouble(
*op)
Part of the
.Return the imaginary part of op as a C double.
If op is not a Python complex number object but has a
method, this method will first be called to convert op to a Python complex number object. If __complex__() is not defined then it falls back to call
and returns 0.0 on success.
Upon failure, this method returns -1.0 with an exception set, so one should call
to check for errors.
Changed in version 3.13: Use
if available.
PyComplex_AsCComplex(
*op)
Return the
value of the complex number op.
If op is not a Python complex number object but has a
method, this method will first be called to convert op to a Python complex number object. If __complex__() is not defined then it falls back to
. If __float__() is not defined then it falls back to
.
Upon failure, this method returns
with
set to -1.0 and with an exception set, so one should call
to check for errors.
Changed in version 3.8: Use
if available.