Complex Number Objects

Python’s complex number objects are implemented as two distinct types whenviewed from the C API: one is the Python object exposed to Python programs, andthe 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 returnthem as results do soby value rather than dereferencing them throughpointers. This is consistent throughout the API.

typePy_complex

The C structure which corresponds to the value portion of a Python complexnumber object. Most of the functions for dealing with complex number objectsuse structures of this type as input or output values, as appropriate.

doublereal
doubleimag

The structure is defined as:

typedefstruct{doublereal;doubleimag;}Py_complex;
Py_complex_Py_c_sum(Py_complexleft,Py_complexright)

Return the sum of two complex numbers, using the CPy_complexrepresentation.

Py_complex_Py_c_diff(Py_complexleft,Py_complexright)

Return the difference between two complex numbers, using the CPy_complex representation.

Py_complex_Py_c_neg(Py_complexnum)

Return the negation of the complex numbernum, using the CPy_complex representation.

Py_complex_Py_c_prod(Py_complexleft,Py_complexright)

Return the product of two complex numbers, using the CPy_complexrepresentation.

Py_complex_Py_c_quot(Py_complexdividend,Py_complexdivisor)

Return the quotient of two complex numbers, using the CPy_complexrepresentation.

Ifdivisor is null, this method returns zero and setserrno toEDOM.

Py_complex_Py_c_pow(Py_complexnum,Py_complexexp)

Return the exponentiation ofnum byexp, using the CPy_complexrepresentation.

Ifnum is null andexp is not a positive real number,this method returns zero and setserrno toEDOM.

Complex Numbers as Python Objects

typePyComplexObject

This subtype ofPyObject represents a Python complex number object.

PyTypeObjectPyComplex_Type
Part of theStable ABI.

This instance ofPyTypeObject represents the Python complex numbertype. It is the same object ascomplex in the Python layer.

intPyComplex_Check(PyObject*p)

Return true if its argument is aPyComplexObject or a subtype ofPyComplexObject. This function always succeeds.

intPyComplex_CheckExact(PyObject*p)

Return true if its argument is aPyComplexObject, but not a subtype ofPyComplexObject. This function always succeeds.

PyObject*PyComplex_FromCComplex(Py_complexv)
Return value: New reference.

Create a new Python complex number object from a CPy_complex value.ReturnNULL with an exception set on error.

PyObject*PyComplex_FromDoubles(doublereal,doubleimag)
Return value: New reference. Part of theStable ABI.

Return a newPyComplexObject object fromreal andimag.ReturnNULL with an exception set on error.

doublePyComplex_RealAsDouble(PyObject*op)
Part of theStable ABI.

Return the real part ofop as a Cdouble.

Ifop is not a Python complex number object but has a__complex__() method, this method will first be called toconvertop to a Python complex number object. If__complex__() isnot defined then it falls back to callPyFloat_AsDouble() andreturns its result.

Upon failure, this method returns-1.0 with an exception set, so oneshould callPyErr_Occurred() to check for errors.

Changed in version 3.13:Use__complex__() if available.

doublePyComplex_ImagAsDouble(PyObject*op)
Part of theStable ABI.

Return the imaginary part ofop as a Cdouble.

Ifop is not a Python complex number object but has a__complex__() method, this method will first be called toconvertop to a Python complex number object. If__complex__() isnot defined then it falls back to callPyFloat_AsDouble() andreturns0.0 on success.

Upon failure, this method returns-1.0 with an exception set, so oneshould callPyErr_Occurred() to check for errors.

Changed in version 3.13:Use__complex__() if available.

Py_complexPyComplex_AsCComplex(PyObject*op)

Return thePy_complex value of the complex numberop.

Ifop is not a Python complex number object but has a__complex__()method, this method will first be called to convertop to a Python complexnumber object. If__complex__() is not defined then it falls back to__float__(). If__float__() is not defined then it falls backto__index__().

Upon failure, this method returnsPy_complexwithreal set to-1.0 and with an exception set, so oneshould callPyErr_Occurred() to check for errors.

Changed in version 3.8:Use__index__() if available.