.. highlight:: c

.. _number:

Number Protocol

.. c:function:: int PyNumber_Check(PyObject *o)

Returns 1 if the object o provides numeric protocols, and false otherwise. This function always succeeds.

.. versionchanged:: 3.8 Returns 1 if o is an index integer.

.. c:function:: PyObject* PyNumber_Add(PyObject *o1, PyObject *o2)

Returns the result of adding o1 and o2, or NULL on failure. This is the equivalent of the Python expression o1 + o2.

.. c:function:: PyObject* PyNumber_Subtract(PyObject *o1, PyObject *o2)

Returns the result of subtracting o2 from o1, or NULL on failure. This is the equivalent of the Python expression o1 - o2.

.. c:function:: PyObject* PyNumber_Multiply(PyObject *o1, PyObject *o2)

Returns the result of multiplying o1 and o2, or NULL on failure. This is the equivalent of the Python expression o1 * o2.

.. c:function:: PyObject* PyNumber_MatrixMultiply(PyObject *o1, PyObject *o2)

Returns the result of matrix multiplication on o1 and o2, or NULL on failure. This is the equivalent of the Python expression o1 @ o2.

.. versionadded:: 3.5

.. c:function:: PyObject* PyNumber_FloorDivide(PyObject *o1, PyObject *o2)

Return the floor of o1 divided by o2, or NULL on failure. This is the equivalent of the Python expression o1 // o2.

.. c:function:: PyObject* PyNumber_TrueDivide(PyObject *o1, PyObject *o2)

Return a reasonable approximation for the mathematical value of o1 divided by o2, or NULL on failure. The return value is "approximate" because binary floating-point numbers are approximate; it is not possible to represent all real numbers in base two. This function can return a floating-point value when passed two integers. This is the equivalent of the Python expression o1 / o2.

.. c:function:: PyObject* PyNumber_Remainder(PyObject *o1, PyObject *o2)

Returns the remainder of dividing o1 by o2, or NULL on failure. This is the equivalent of the Python expression o1 % o2.

.. c:function:: PyObject* PyNumber_Divmod(PyObject *o1, PyObject *o2)

.. index:: pair: built-in function; divmod

See the built-in function :func:divmod. Returns NULL on failure. This is the equivalent of the Python expression divmod(o1, o2).

.. c:function:: PyObject* PyNumber_Power(PyObject *o1, PyObject *o2, PyObject *o3)

.. index:: pair: built-in function; pow

See the built-in function :func:pow. Returns NULL on failure. This is the equivalent of the Python expression pow(o1, o2, o3), where o3 is optional. If o3 is to be ignored, pass :c:data:Py_None in its place (passing NULL for o3 would cause an illegal memory access).

.. c:function:: PyObject* PyNumber_Negative(PyObject *o)

Returns the negation of o on success, or NULL on failure. This is the equivalent of the Python expression -o.

.. c:function:: PyObject* PyNumber_Positive(PyObject *o)

Returns o on success, or NULL on failure. This is the equivalent of the Python expression +o.

.. c:function:: PyObject* PyNumber_Absolute(PyObject *o)

.. index:: pair: built-in function; abs

Returns the absolute value of o, or NULL on failure. This is the equivalent of the Python expression abs(o).

.. c:function:: PyObject* PyNumber_Invert(PyObject *o)

Returns the bitwise negation of o on success, or NULL on failure. This is the equivalent of the Python expression ~o.

.. c:function:: PyObject* PyNumber_Lshift(PyObject *o1, PyObject *o2)

Returns the result of left shifting o1 by o2 on success, or NULL on failure. This is the equivalent of the Python expression o1 << o2.

.. c:function:: PyObject* PyNumber_Rshift(PyObject *o1, PyObject *o2)

Returns the result of right shifting o1 by o2 on success, or NULL on failure. This is the equivalent of the Python expression o1 >> o2.

.. c:function:: PyObject* PyNumber_And(PyObject *o1, PyObject *o2)

Returns the "bitwise and" of o1 and o2 on success and NULL on failure. This is the equivalent of the Python expression o1 & o2.

.. c:function:: PyObject* PyNumber_Xor(PyObject *o1, PyObject *o2)

Returns the "bitwise exclusive or" of o1 by o2 on success, or NULL on failure. This is the equivalent of the Python expression o1 ^ o2.

.. c:function:: PyObject* PyNumber_Or(PyObject *o1, PyObject *o2)

Returns the "bitwise or" of o1 and o2 on success, or NULL on failure. This is the equivalent of the Python expression o1 | o2.

.. c:function:: PyObject* PyNumber_InPlaceAdd(PyObject *o1, PyObject *o2)

Returns the result of adding o1 and o2, or NULL on failure. The operation is done in-place when o1 supports it. This is the equivalent of the Python statement o1 += o2.

.. c:function:: PyObject* PyNumber_InPlaceSubtract(PyObject *o1, PyObject *o2)

Returns the result of subtracting o2 from o1, or NULL on failure. The operation is done in-place when o1 supports it. This is the equivalent of the Python statement o1 -= o2.

.. c:function:: PyObject* PyNumber_InPlaceMultiply(PyObject *o1, PyObject *o2)

Returns the result of multiplying o1 and o2, or NULL on failure. The operation is done in-place when o1 supports it. This is the equivalent of the Python statement o1 *= o2.

.. c:function:: PyObject* PyNumber_InPlaceMatrixMultiply(PyObject *o1, PyObject *o2)

Returns the result of matrix multiplication on o1 and o2, or NULL on failure. The operation is done in-place when o1 supports it. This is the equivalent of the Python statement o1 @= o2.

.. versionadded:: 3.5

.. c:function:: PyObject* PyNumber_InPlaceFloorDivide(PyObject *o1, PyObject *o2)

Returns the mathematical floor of dividing o1 by o2, or NULL on failure. The operation is done in-place when o1 supports it. This is the equivalent of the Python statement o1 //= o2.

.. c:function:: PyObject* PyNumber_InPlaceTrueDivide(PyObject *o1, PyObject *o2)

Return a reasonable approximation for the mathematical value of o1 divided by o2, or NULL on failure. The return value is "approximate" because binary floating-point numbers are approximate; it is not possible to represent all real numbers in base two. This function can return a floating-point value when passed two integers. The operation is done in-place when o1 supports it. This is the equivalent of the Python statement o1 /= o2.

.. c:function:: PyObject* PyNumber_InPlaceRemainder(PyObject *o1, PyObject *o2)

Returns the remainder of dividing o1 by o2, or NULL on failure. The operation is done in-place when o1 supports it. This is the equivalent of the Python statement o1 %= o2.

.. c:function:: PyObject* PyNumber_InPlacePower(PyObject *o1, PyObject *o2, PyObject *o3)

.. index:: pair: built-in function; pow

See the built-in function :func:pow. Returns NULL on failure. The operation is done in-place when o1 supports it. This is the equivalent of the Python statement o1 **= o2 when o3 is :c:data:Py_None, or an in-place variant of pow(o1, o2, o3) otherwise. If o3 is to be ignored, pass :c:data:Py_None in its place (passing NULL for o3 would cause an illegal memory access).

.. c:function:: PyObject* PyNumber_InPlaceLshift(PyObject *o1, PyObject *o2)

Returns the result of left shifting o1 by o2 on success, or NULL on failure. The operation is done in-place when o1 supports it. This is the equivalent of the Python statement o1 <<= o2.

.. c:function:: PyObject* PyNumber_InPlaceRshift(PyObject *o1, PyObject *o2)

Returns the result of right shifting o1 by o2 on success, or NULL on failure. The operation is done in-place when o1 supports it. This is the equivalent of the Python statement o1 >>= o2.

.. c:function:: PyObject* PyNumber_InPlaceAnd(PyObject *o1, PyObject *o2)

Returns the "bitwise and" of o1 and o2 on success and NULL on failure. The operation is done in-place when o1 supports it. This is the equivalent of the Python statement o1 &= o2.

.. c:function:: PyObject* PyNumber_InPlaceXor(PyObject *o1, PyObject *o2)

Returns the "bitwise exclusive or" of o1 by o2 on success, or NULL on failure. The operation is done in-place when o1 supports it. This is the equivalent of the Python statement o1 ^= o2.

.. c:function:: PyObject* PyNumber_InPlaceOr(PyObject *o1, PyObject *o2)

Returns the "bitwise or" of o1 and o2 on success, or NULL on failure. The operation is done in-place when o1 supports it. This is the equivalent of the Python statement o1 |= o2.

.. c:function:: PyObject* PyNumber_Long(PyObject *o)

.. index:: pair: built-in function; int

Returns the o converted to an integer object on success, or NULL on failure. This is the equivalent of the Python expression int(o).

.. c:function:: PyObject* PyNumber_Float(PyObject *o)

.. index:: pair: built-in function; float

Returns the o converted to a float object on success, or NULL on failure. This is the equivalent of the Python expression float(o).

.. c:function:: PyObject* PyNumber_Index(PyObject *o)

Returns the o converted to a Python int on success or NULL with a :exc:TypeError exception raised on failure.

.. versionchanged:: 3.10 The result always has exact type :class:int. Previously, the result could have been an instance of a subclass of int.

.. c:function:: PyObject* PyNumber_ToBase(PyObject *n, int base)

Returns the integer n converted to base base as a string. The base argument must be one of 2, 8, 10, or 16. For base 2, 8, or 16, the returned string is prefixed with a base marker of '0b', '0o', or '0x', respectively. If n is not a Python int, it is converted with :c:func:PyNumber_Index first.

.. c:function:: Py_ssize_t PyNumber_AsSsize_t(PyObject *o, PyObject *exc)

Returns o converted to a :c:type:Py_ssize_t value if o can be interpreted as an integer. If the call fails, an exception is raised and -1 is returned.

If o can be converted to a Python int but the attempt to convert to a :c:type:Py_ssize_t value would raise an :exc:OverflowError, then the exc argument is the type of exception that will be raised (usually :exc:IndexError or :exc:OverflowError). If exc is NULL, then the exception is cleared and the value is clipped to PY_SSIZE_T_MIN for a negative integer or PY_SSIZE_T_MAX for a positive integer.

.. c:function:: int PyIndex_Check(PyObject *o)

Returns 1 if o is an index integer (has the nb_index slot of the tp_as_number structure filled in), and 0 otherwise. This function always succeeds.