complex.md

complex

contents

• related file
• memory layout
• example

related file

• cpython/Objects/complexobject.c
• cpython/Include/complexobject.h
• cpython/clinic/complexobject.c.h

memory layout

the PyComplexObject stores two double precision floating point number inside

the handling process and representation are mostly the same as float object

example

c = complex(0, 1)

d = complex(0.1, -0.2)

let's read the add function

Py_complex
_Py_c_sum(Py_complex a, Py_complex b)
{
    Py_complex r;
    r.real = a.real + b.real;
    r.imag = a.imag + b.imag;
    return r;
}

static PyObject *
complex_add(PyObject *v, PyObject *w)
{
    Py_complex result;
    Py_complex a, b;
    TO_COMPLEX(v, a); // check the type, covert to complex if type is not complex
    TO_COMPLEX(w, b);
    PyFPE_START_PROTECT("complex_add", return 0) // useless after version 3.7
    result = _Py_c_sum(a, b); // sum the complex
    PyFPE_END_PROTECT(result) // useless after version 3.7
    return PyComplex_FromCComplex(result);
}

the add operation is quite simple, sum the real, sum the image part and return the new value

the sub/divide/pow/neg operations are similar

>>> e = c + d
>>> repr(e)
'(0.1+0.8j)'