1.. highlight:: c 2 3.. _complexobjects: 4 5Complex Number Objects 6---------------------- 7 8.. index:: object: complex number 9 10Python's complex number objects are implemented as two distinct types when 11viewed from the C API: one is the Python object exposed to Python programs, and 12the other is a C structure which represents the actual complex number value. 13The API provides functions for working with both. 14 15 16Complex Numbers as C Structures 17^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 18 19Note that the functions which accept these structures as parameters and return 20them as results do so *by value* rather than dereferencing them through 21pointers. This is consistent throughout the API. 22 23 24.. c:type:: Py_complex 25 26 The C structure which corresponds to the value portion of a Python complex 27 number object. Most of the functions for dealing with complex number objects 28 use structures of this type as input or output values, as appropriate. It is 29 defined as:: 30 31 typedef struct { 32 double real; 33 double imag; 34 } Py_complex; 35 36 37.. c:function:: Py_complex _Py_c_sum(Py_complex left, Py_complex right) 38 39 Return the sum of two complex numbers, using the C :c:type:`Py_complex` 40 representation. 41 42 43.. c:function:: Py_complex _Py_c_diff(Py_complex left, Py_complex right) 44 45 Return the difference between two complex numbers, using the C 46 :c:type:`Py_complex` representation. 47 48 49.. c:function:: Py_complex _Py_c_neg(Py_complex num) 50 51 Return the negation of the complex number *num*, using the C 52 :c:type:`Py_complex` representation. 53 54 55.. c:function:: Py_complex _Py_c_prod(Py_complex left, Py_complex right) 56 57 Return the product of two complex numbers, using the C :c:type:`Py_complex` 58 representation. 59 60 61.. c:function:: Py_complex _Py_c_quot(Py_complex dividend, Py_complex divisor) 62 63 Return the quotient of two complex numbers, using the C :c:type:`Py_complex` 64 representation. 65 66 If *divisor* is null, this method returns zero and sets 67 :c:data:`errno` to :c:data:`EDOM`. 68 69 70.. c:function:: Py_complex _Py_c_pow(Py_complex num, Py_complex exp) 71 72 Return the exponentiation of *num* by *exp*, using the C :c:type:`Py_complex` 73 representation. 74 75 If *num* is null and *exp* is not a positive real number, 76 this method returns zero and sets :c:data:`errno` to :c:data:`EDOM`. 77 78 79Complex Numbers as Python Objects 80^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 81 82 83.. c:type:: PyComplexObject 84 85 This subtype of :c:type:`PyObject` represents a Python complex number object. 86 87 88.. c:var:: PyTypeObject PyComplex_Type 89 90 This instance of :c:type:`PyTypeObject` represents the Python complex number 91 type. It is the same object as :class:`complex` in the Python layer. 92 93 94.. c:function:: int PyComplex_Check(PyObject *p) 95 96 Return true if its argument is a :c:type:`PyComplexObject` or a subtype of 97 :c:type:`PyComplexObject`. This function always succeeds. 98 99 100.. c:function:: int PyComplex_CheckExact(PyObject *p) 101 102 Return true if its argument is a :c:type:`PyComplexObject`, but not a subtype of 103 :c:type:`PyComplexObject`. This function always succeeds. 104 105 106.. c:function:: PyObject* PyComplex_FromCComplex(Py_complex v) 107 108 Create a new Python complex number object from a C :c:type:`Py_complex` value. 109 110 111.. c:function:: PyObject* PyComplex_FromDoubles(double real, double imag) 112 113 Return a new :c:type:`PyComplexObject` object from *real* and *imag*. 114 115 116.. c:function:: double PyComplex_RealAsDouble(PyObject *op) 117 118 Return the real part of *op* as a C :c:type:`double`. 119 120 121.. c:function:: double PyComplex_ImagAsDouble(PyObject *op) 122 123 Return the imaginary part of *op* as a C :c:type:`double`. 124 125 126.. c:function:: Py_complex PyComplex_AsCComplex(PyObject *op) 127 128 Return the :c:type:`Py_complex` value of the complex number *op*. 129 130 If *op* is not a Python complex number object but has a :meth:`__complex__` 131 method, this method will first be called to convert *op* to a Python complex 132 number object. If ``__complex__()`` is not defined then it falls back to 133 :meth:`__float__`. If ``__float__()`` is not defined then it falls back 134 to :meth:`__index__`. Upon failure, this method returns ``-1.0`` as a real 135 value. 136 137 .. versionchanged:: 3.8 138 Use :meth:`__index__` if available. 139