1.. highlight:: c
2
3.. _number:
4
5Number Protocol
6===============
7
8
9.. c:function:: int PyNumber_Check(PyObject *o)
10
11   Returns ``1`` if the object *o* provides numeric protocols, and false otherwise.
12   This function always succeeds.
13
14   .. versionchanged:: 3.8
15      Returns ``1`` if *o* is an index integer.
16
17
18.. c:function:: PyObject* PyNumber_Add(PyObject *o1, PyObject *o2)
19
20   Returns the result of adding *o1* and *o2*, or ``NULL`` on failure.  This is the
21   equivalent of the Python expression ``o1 + o2``.
22
23
24.. c:function:: PyObject* PyNumber_Subtract(PyObject *o1, PyObject *o2)
25
26   Returns the result of subtracting *o2* from *o1*, or ``NULL`` on failure.  This is
27   the equivalent of the Python expression ``o1 - o2``.
28
29
30.. c:function:: PyObject* PyNumber_Multiply(PyObject *o1, PyObject *o2)
31
32   Returns the result of multiplying *o1* and *o2*, or ``NULL`` on failure.  This is
33   the equivalent of the Python expression ``o1 * o2``.
34
35
36.. c:function:: PyObject* PyNumber_MatrixMultiply(PyObject *o1, PyObject *o2)
37
38   Returns the result of matrix multiplication on *o1* and *o2*, or ``NULL`` on
39   failure.  This is the equivalent of the Python expression ``o1 @ o2``.
40
41   .. versionadded:: 3.5
42
43
44.. c:function:: PyObject* PyNumber_FloorDivide(PyObject *o1, PyObject *o2)
45
46   Return the floor of *o1* divided by *o2*, or ``NULL`` on failure.  This is
47   the equivalent of the Python expression ``o1 // o2``.
48
49
50.. c:function:: PyObject* PyNumber_TrueDivide(PyObject *o1, PyObject *o2)
51
52   Return a reasonable approximation for the mathematical value of *o1* divided by
53   *o2*, or ``NULL`` on failure.  The return value is "approximate" because binary
54   floating point numbers are approximate; it is not possible to represent all real
55   numbers in base two.  This function can return a floating point value when
56   passed two integers.  This is the equivalent of the Python expression ``o1 / o2``.
57
58
59.. c:function:: PyObject* PyNumber_Remainder(PyObject *o1, PyObject *o2)
60
61   Returns the remainder of dividing *o1* by *o2*, or ``NULL`` on failure.  This is
62   the equivalent of the Python expression ``o1 % o2``.
63
64
65.. c:function:: PyObject* PyNumber_Divmod(PyObject *o1, PyObject *o2)
66
67   .. index:: pair: built-in function; divmod
68
69   See the built-in function :func:`divmod`. Returns ``NULL`` on failure.  This is
70   the equivalent of the Python expression ``divmod(o1, o2)``.
71
72
73.. c:function:: PyObject* PyNumber_Power(PyObject *o1, PyObject *o2, PyObject *o3)
74
75   .. index:: pair: built-in function; pow
76
77   See the built-in function :func:`pow`. Returns ``NULL`` on failure.  This is the
78   equivalent of the Python expression ``pow(o1, o2, o3)``, where *o3* is optional.
79   If *o3* is to be ignored, pass :c:data:`Py_None` in its place (passing ``NULL`` for
80   *o3* would cause an illegal memory access).
81
82
83.. c:function:: PyObject* PyNumber_Negative(PyObject *o)
84
85   Returns the negation of *o* on success, or ``NULL`` on failure. This is the
86   equivalent of the Python expression ``-o``.
87
88
89.. c:function:: PyObject* PyNumber_Positive(PyObject *o)
90
91   Returns *o* on success, or ``NULL`` on failure.  This is the equivalent of the
92   Python expression ``+o``.
93
94
95.. c:function:: PyObject* PyNumber_Absolute(PyObject *o)
96
97   .. index:: pair: built-in function; abs
98
99   Returns the absolute value of *o*, or ``NULL`` on failure.  This is the equivalent
100   of the Python expression ``abs(o)``.
101
102
103.. c:function:: PyObject* PyNumber_Invert(PyObject *o)
104
105   Returns the bitwise negation of *o* on success, or ``NULL`` on failure.  This is
106   the equivalent of the Python expression ``~o``.
107
108
109.. c:function:: PyObject* PyNumber_Lshift(PyObject *o1, PyObject *o2)
110
111   Returns the result of left shifting *o1* by *o2* on success, or ``NULL`` on
112   failure.  This is the equivalent of the Python expression ``o1 << o2``.
113
114
115.. c:function:: PyObject* PyNumber_Rshift(PyObject *o1, PyObject *o2)
116
117   Returns the result of right shifting *o1* by *o2* on success, or ``NULL`` on
118   failure.  This is the equivalent of the Python expression ``o1 >> o2``.
119
120
121.. c:function:: PyObject* PyNumber_And(PyObject *o1, PyObject *o2)
122
123   Returns the "bitwise and" of *o1* and *o2* on success and ``NULL`` on failure.
124   This is the equivalent of the Python expression ``o1 & o2``.
125
126
127.. c:function:: PyObject* PyNumber_Xor(PyObject *o1, PyObject *o2)
128
129   Returns the "bitwise exclusive or" of *o1* by *o2* on success, or ``NULL`` on
130   failure.  This is the equivalent of the Python expression ``o1 ^ o2``.
131
132
133.. c:function:: PyObject* PyNumber_Or(PyObject *o1, PyObject *o2)
134
135   Returns the "bitwise or" of *o1* and *o2* on success, or ``NULL`` on failure.
136   This is the equivalent of the Python expression ``o1 | o2``.
137
138
139.. c:function:: PyObject* PyNumber_InPlaceAdd(PyObject *o1, PyObject *o2)
140
141   Returns the result of adding *o1* and *o2*, or ``NULL`` on failure.  The operation
142   is done *in-place* when *o1* supports it.  This is the equivalent of the Python
143   statement ``o1 += o2``.
144
145
146.. c:function:: PyObject* PyNumber_InPlaceSubtract(PyObject *o1, PyObject *o2)
147
148   Returns the result of subtracting *o2* from *o1*, or ``NULL`` on failure.  The
149   operation is done *in-place* when *o1* supports it.  This is the equivalent of
150   the Python statement ``o1 -= o2``.
151
152
153.. c:function:: PyObject* PyNumber_InPlaceMultiply(PyObject *o1, PyObject *o2)
154
155   Returns the result of multiplying *o1* and *o2*, or ``NULL`` on failure.  The
156   operation is done *in-place* when *o1* supports it.  This is the equivalent of
157   the Python statement ``o1 *= o2``.
158
159
160.. c:function:: PyObject* PyNumber_InPlaceMatrixMultiply(PyObject *o1, PyObject *o2)
161
162   Returns the result of matrix multiplication on *o1* and *o2*, or ``NULL`` on
163   failure.  The operation is done *in-place* when *o1* supports it.  This is
164   the equivalent of the Python statement ``o1 @= o2``.
165
166   .. versionadded:: 3.5
167
168
169.. c:function:: PyObject* PyNumber_InPlaceFloorDivide(PyObject *o1, PyObject *o2)
170
171   Returns the mathematical floor of dividing *o1* by *o2*, or ``NULL`` on failure.
172   The operation is done *in-place* when *o1* supports it.  This is the equivalent
173   of the Python statement ``o1 //= o2``.
174
175
176.. c:function:: PyObject* PyNumber_InPlaceTrueDivide(PyObject *o1, PyObject *o2)
177
178   Return a reasonable approximation for the mathematical value of *o1* divided by
179   *o2*, or ``NULL`` on failure.  The return value is "approximate" because binary
180   floating point numbers are approximate; it is not possible to represent all real
181   numbers in base two.  This function can return a floating point value when
182   passed two integers.  The operation is done *in-place* when *o1* supports it.
183   This is the equivalent of the Python statement ``o1 /= o2``.
184
185
186.. c:function:: PyObject* PyNumber_InPlaceRemainder(PyObject *o1, PyObject *o2)
187
188   Returns the remainder of dividing *o1* by *o2*, or ``NULL`` on failure.  The
189   operation is done *in-place* when *o1* supports it.  This is the equivalent of
190   the Python statement ``o1 %= o2``.
191
192
193.. c:function:: PyObject* PyNumber_InPlacePower(PyObject *o1, PyObject *o2, PyObject *o3)
194
195   .. index:: pair: built-in function; pow
196
197   See the built-in function :func:`pow`. Returns ``NULL`` on failure.  The operation
198   is done *in-place* when *o1* supports it.  This is the equivalent of the Python
199   statement ``o1 **= o2`` when o3 is :c:data:`Py_None`, or an in-place variant of
200   ``pow(o1, o2, o3)`` otherwise. If *o3* is to be ignored, pass :c:data:`Py_None`
201   in its place (passing ``NULL`` for *o3* would cause an illegal memory access).
202
203
204.. c:function:: PyObject* PyNumber_InPlaceLshift(PyObject *o1, PyObject *o2)
205
206   Returns the result of left shifting *o1* by *o2* on success, or ``NULL`` on
207   failure.  The operation is done *in-place* when *o1* supports it.  This is the
208   equivalent of the Python statement ``o1 <<= o2``.
209
210
211.. c:function:: PyObject* PyNumber_InPlaceRshift(PyObject *o1, PyObject *o2)
212
213   Returns the result of right shifting *o1* by *o2* on success, or ``NULL`` on
214   failure.  The operation is done *in-place* when *o1* supports it.  This is the
215   equivalent of the Python statement ``o1 >>= o2``.
216
217
218.. c:function:: PyObject* PyNumber_InPlaceAnd(PyObject *o1, PyObject *o2)
219
220   Returns the "bitwise and" of *o1* and *o2* on success and ``NULL`` on failure. The
221   operation is done *in-place* when *o1* supports it.  This is the equivalent of
222   the Python statement ``o1 &= o2``.
223
224
225.. c:function:: PyObject* PyNumber_InPlaceXor(PyObject *o1, PyObject *o2)
226
227   Returns the "bitwise exclusive or" of *o1* by *o2* on success, or ``NULL`` on
228   failure.  The operation is done *in-place* when *o1* supports it.  This is the
229   equivalent of the Python statement ``o1 ^= o2``.
230
231
232.. c:function:: PyObject* PyNumber_InPlaceOr(PyObject *o1, PyObject *o2)
233
234   Returns the "bitwise or" of *o1* and *o2* on success, or ``NULL`` on failure.  The
235   operation is done *in-place* when *o1* supports it.  This is the equivalent of
236   the Python statement ``o1 |= o2``.
237
238
239.. c:function:: PyObject* PyNumber_Long(PyObject *o)
240
241   .. index:: pair: built-in function; int
242
243   Returns the *o* converted to an integer object on success, or ``NULL`` on
244   failure.  This is the equivalent of the Python expression ``int(o)``.
245
246
247.. c:function:: PyObject* PyNumber_Float(PyObject *o)
248
249   .. index:: pair: built-in function; float
250
251   Returns the *o* converted to a float object on success, or ``NULL`` on failure.
252   This is the equivalent of the Python expression ``float(o)``.
253
254
255.. c:function:: PyObject* PyNumber_Index(PyObject *o)
256
257   Returns the *o* converted to a Python int on success or ``NULL`` with a
258   :exc:`TypeError` exception raised on failure.
259
260   .. versionchanged:: 3.10
261      The result always has exact type :class:`int`.  Previously, the result
262      could have been an instance of a subclass of ``int``.
263
264
265.. c:function:: PyObject* PyNumber_ToBase(PyObject *n, int base)
266
267   Returns the integer *n* converted to base *base* as a string.  The *base*
268   argument must be one of 2, 8, 10, or 16.  For base 2, 8, or 16, the
269   returned string is prefixed with a base marker of ``'0b'``, ``'0o'``, or
270   ``'0x'``, respectively.  If *n* is not a Python int, it is converted with
271   :c:func:`PyNumber_Index` first.
272
273
274.. c:function:: Py_ssize_t PyNumber_AsSsize_t(PyObject *o, PyObject *exc)
275
276   Returns *o* converted to a :c:type:`Py_ssize_t` value if *o* can be interpreted as an
277   integer.  If the call fails, an exception is raised and ``-1`` is returned.
278
279   If *o* can be converted to a Python int but the attempt to
280   convert to a :c:type:`Py_ssize_t` value would raise an :exc:`OverflowError`, then the
281   *exc* argument is the type of exception that will be raised (usually
282   :exc:`IndexError` or :exc:`OverflowError`).  If *exc* is ``NULL``, then the
283   exception is cleared and the value is clipped to ``PY_SSIZE_T_MIN`` for a negative
284   integer or ``PY_SSIZE_T_MAX`` for a positive integer.
285
286
287.. c:function:: int PyIndex_Check(PyObject *o)
288
289   Returns ``1`` if *o* is an index integer (has the ``nb_index`` slot of the
290   ``tp_as_number`` structure filled in), and ``0`` otherwise.
291   This function always succeeds.
292