blob: 5c1d026a330ae7e91d096889efedcabfdf3e0a5a [file] [log] [blame]
.. highlight:: c
.. _longobjects:
Integer Objects
---------------
.. index:: pair: object; long integer
pair: object; integer
All integers are implemented as "long" integer objects of arbitrary size.
On error, most ``PyLong_As*`` APIs return ``(return type)-1`` which cannot be
distinguished from a number. Use :c:func:`PyErr_Occurred` to disambiguate.
.. c:type:: PyLongObject
This subtype of :c:type:`PyObject` represents a Python integer object.
.. c:var:: PyTypeObject PyLong_Type
This instance of :c:type:`PyTypeObject` represents the Python integer type.
This is the same object as :class:`int` in the Python layer.
.. c:function:: int PyLong_Check(PyObject *p)
Return true if its argument is a :c:type:`PyLongObject` or a subtype of
:c:type:`PyLongObject`. This function always succeeds.
.. c:function:: int PyLong_CheckExact(PyObject *p)
Return true if its argument is a :c:type:`PyLongObject`, but not a subtype of
:c:type:`PyLongObject`. This function always succeeds.
.. c:function:: PyObject* PyLong_FromLong(long v)
Return a new :c:type:`PyLongObject` object from *v*, or ``NULL`` on failure.
The current implementation keeps an array of integer objects for all integers
between ``-5`` and ``256``. When you create an int in that range you actually
just get back a reference to the existing object.
.. c:function:: PyObject* PyLong_FromUnsignedLong(unsigned long v)
Return a new :c:type:`PyLongObject` object from a C :c:expr:`unsigned long`, or
``NULL`` on failure.
.. c:function:: PyObject* PyLong_FromSsize_t(Py_ssize_t v)
Return a new :c:type:`PyLongObject` object from a C :c:type:`Py_ssize_t`, or
``NULL`` on failure.
.. c:function:: PyObject* PyLong_FromSize_t(size_t v)
Return a new :c:type:`PyLongObject` object from a C :c:type:`size_t`, or
``NULL`` on failure.
.. c:function:: PyObject* PyLong_FromLongLong(long long v)
Return a new :c:type:`PyLongObject` object from a C :c:expr:`long long`, or ``NULL``
on failure.
.. c:function:: PyObject* PyLong_FromUnsignedLongLong(unsigned long long v)
Return a new :c:type:`PyLongObject` object from a C :c:expr:`unsigned long long`,
or ``NULL`` on failure.
.. c:function:: PyObject* PyLong_FromDouble(double v)
Return a new :c:type:`PyLongObject` object from the integer part of *v*, or
``NULL`` on failure.
.. c:function:: PyObject* PyLong_FromString(const char *str, char **pend, int base)
Return a new :c:type:`PyLongObject` based on the string value in *str*, which
is interpreted according to the radix in *base*, or ``NULL`` on failure. If
*pend* is non-``NULL``, *\*pend* will point to the end of *str* on success or
to the first character that could not be processed on error. If *base* is ``0``,
*str* is interpreted using the :ref:`integers` definition; in this case, leading
zeros in a non-zero decimal number raises a :exc:`ValueError`. If *base* is not
``0``, it must be between ``2`` and ``36``, inclusive. Leading and trailing
whitespace and single underscores after a base specifier and between digits are
ignored. If there are no digits or *str* is not NULL-terminated following the
digits and trailing whitespace, :exc:`ValueError` will be raised.
.. seealso:: Python methods :meth:`int.to_bytes` and :meth:`int.from_bytes`
to convert a :c:type:`PyLongObject` to/from an array of bytes in base
``256``. You can call those from C using :c:func:`PyObject_CallMethod`.
.. c:function:: PyObject* PyLong_FromUnicodeObject(PyObject *u, int base)
Convert a sequence of Unicode digits in the string *u* to a Python integer
value.
.. versionadded:: 3.3
.. c:function:: PyObject* PyLong_FromVoidPtr(void *p)
Create a Python integer from the pointer *p*. The pointer value can be
retrieved from the resulting value using :c:func:`PyLong_AsVoidPtr`.
.. XXX alias PyLong_AS_LONG (for now)
.. c:function:: long PyLong_AsLong(PyObject *obj)
.. index::
single: LONG_MAX
single: OverflowError (built-in exception)
Return a C :c:expr:`long` representation of *obj*. If *obj* is not an
instance of :c:type:`PyLongObject`, first call its :meth:`__index__` method
(if present) to convert it to a :c:type:`PyLongObject`.
Raise :exc:`OverflowError` if the value of *obj* is out of range for a
:c:expr:`long`.
Returns ``-1`` on error. Use :c:func:`PyErr_Occurred` to disambiguate.
.. versionchanged:: 3.8
Use :meth:`__index__` if available.
.. versionchanged:: 3.10
This function will no longer use :meth:`__int__`.
.. c:function:: long PyLong_AsLongAndOverflow(PyObject *obj, int *overflow)
Return a C :c:expr:`long` representation of *obj*. If *obj* is not an
instance of :c:type:`PyLongObject`, first call its :meth:`__index__`
method (if present) to convert it to a :c:type:`PyLongObject`.
If the value of *obj* is greater than :const:`LONG_MAX` or less than
:const:`LONG_MIN`, set *\*overflow* to ``1`` or ``-1``, respectively, and
return ``-1``; otherwise, set *\*overflow* to ``0``. If any other exception
occurs set *\*overflow* to ``0`` and return ``-1`` as usual.
Returns ``-1`` on error. Use :c:func:`PyErr_Occurred` to disambiguate.
.. versionchanged:: 3.8
Use :meth:`__index__` if available.
.. versionchanged:: 3.10
This function will no longer use :meth:`__int__`.
.. c:function:: long long PyLong_AsLongLong(PyObject *obj)
.. index::
single: OverflowError (built-in exception)
Return a C :c:expr:`long long` representation of *obj*. If *obj* is not an
instance of :c:type:`PyLongObject`, first call its :meth:`__index__` method
(if present) to convert it to a :c:type:`PyLongObject`.
Raise :exc:`OverflowError` if the value of *obj* is out of range for a
:c:expr:`long long`.
Returns ``-1`` on error. Use :c:func:`PyErr_Occurred` to disambiguate.
.. versionchanged:: 3.8
Use :meth:`__index__` if available.
.. versionchanged:: 3.10
This function will no longer use :meth:`__int__`.
.. c:function:: long long PyLong_AsLongLongAndOverflow(PyObject *obj, int *overflow)
Return a C :c:expr:`long long` representation of *obj*. If *obj* is not an
instance of :c:type:`PyLongObject`, first call its :meth:`__index__` method
(if present) to convert it to a :c:type:`PyLongObject`.
If the value of *obj* is greater than :const:`LLONG_MAX` or less than
:const:`LLONG_MIN`, set *\*overflow* to ``1`` or ``-1``, respectively,
and return ``-1``; otherwise, set *\*overflow* to ``0``. If any other
exception occurs set *\*overflow* to ``0`` and return ``-1`` as usual.
Returns ``-1`` on error. Use :c:func:`PyErr_Occurred` to disambiguate.
.. versionadded:: 3.2
.. versionchanged:: 3.8
Use :meth:`__index__` if available.
.. versionchanged:: 3.10
This function will no longer use :meth:`__int__`.
.. c:function:: Py_ssize_t PyLong_AsSsize_t(PyObject *pylong)
.. index::
single: PY_SSIZE_T_MAX
single: OverflowError (built-in exception)
Return a C :c:type:`Py_ssize_t` representation of *pylong*. *pylong* must
be an instance of :c:type:`PyLongObject`.
Raise :exc:`OverflowError` if the value of *pylong* is out of range for a
:c:type:`Py_ssize_t`.
Returns ``-1`` on error. Use :c:func:`PyErr_Occurred` to disambiguate.
.. c:function:: unsigned long PyLong_AsUnsignedLong(PyObject *pylong)
.. index::
single: ULONG_MAX
single: OverflowError (built-in exception)
Return a C :c:expr:`unsigned long` representation of *pylong*. *pylong*
must be an instance of :c:type:`PyLongObject`.
Raise :exc:`OverflowError` if the value of *pylong* is out of range for a
:c:expr:`unsigned long`.
Returns ``(unsigned long)-1`` on error.
Use :c:func:`PyErr_Occurred` to disambiguate.
.. c:function:: size_t PyLong_AsSize_t(PyObject *pylong)
.. index::
single: SIZE_MAX
single: OverflowError (built-in exception)
Return a C :c:type:`size_t` representation of *pylong*. *pylong* must be
an instance of :c:type:`PyLongObject`.
Raise :exc:`OverflowError` if the value of *pylong* is out of range for a
:c:type:`size_t`.
Returns ``(size_t)-1`` on error.
Use :c:func:`PyErr_Occurred` to disambiguate.
.. c:function:: unsigned long long PyLong_AsUnsignedLongLong(PyObject *pylong)
.. index::
single: OverflowError (built-in exception)
Return a C :c:expr:`unsigned long long` representation of *pylong*. *pylong*
must be an instance of :c:type:`PyLongObject`.
Raise :exc:`OverflowError` if the value of *pylong* is out of range for an
:c:expr:`unsigned long long`.
Returns ``(unsigned long long)-1`` on error.
Use :c:func:`PyErr_Occurred` to disambiguate.
.. versionchanged:: 3.1
A negative *pylong* now raises :exc:`OverflowError`, not :exc:`TypeError`.
.. c:function:: unsigned long PyLong_AsUnsignedLongMask(PyObject *obj)
Return a C :c:expr:`unsigned long` representation of *obj*. If *obj* is not
an instance of :c:type:`PyLongObject`, first call its :meth:`__index__`
method (if present) to convert it to a :c:type:`PyLongObject`.
If the value of *obj* is out of range for an :c:expr:`unsigned long`,
return the reduction of that value modulo ``ULONG_MAX + 1``.
Returns ``(unsigned long)-1`` on error. Use :c:func:`PyErr_Occurred` to
disambiguate.
.. versionchanged:: 3.8
Use :meth:`__index__` if available.
.. versionchanged:: 3.10
This function will no longer use :meth:`__int__`.
.. c:function:: unsigned long long PyLong_AsUnsignedLongLongMask(PyObject *obj)
Return a C :c:expr:`unsigned long long` representation of *obj*. If *obj*
is not an instance of :c:type:`PyLongObject`, first call its
:meth:`__index__` method (if present) to convert it to a
:c:type:`PyLongObject`.
If the value of *obj* is out of range for an :c:expr:`unsigned long long`,
return the reduction of that value modulo ``ULLONG_MAX + 1``.
Returns ``(unsigned long long)-1`` on error. Use :c:func:`PyErr_Occurred`
to disambiguate.
.. versionchanged:: 3.8
Use :meth:`__index__` if available.
.. versionchanged:: 3.10
This function will no longer use :meth:`__int__`.
.. c:function:: double PyLong_AsDouble(PyObject *pylong)
Return a C :c:expr:`double` representation of *pylong*. *pylong* must be
an instance of :c:type:`PyLongObject`.
Raise :exc:`OverflowError` if the value of *pylong* is out of range for a
:c:expr:`double`.
Returns ``-1.0`` on error. Use :c:func:`PyErr_Occurred` to disambiguate.
.. c:function:: void* PyLong_AsVoidPtr(PyObject *pylong)
Convert a Python integer *pylong* to a C :c:expr:`void` pointer.
If *pylong* cannot be converted, an :exc:`OverflowError` will be raised. This
is only assured to produce a usable :c:expr:`void` pointer for values created
with :c:func:`PyLong_FromVoidPtr`.
Returns ``NULL`` on error. Use :c:func:`PyErr_Occurred` to disambiguate.
.. c:function:: int PyUnstable_Long_IsCompact(const PyLongObject* op)
Return 1 if *op* is compact, 0 otherwise.
This function makes it possible for performance-critical code to implement
a fast path for small integers. For compact values use
:c:func:`PyUnstable_Long_CompactValue`; for others fall back to a
:c:func:`PyLong_As* <PyLong_AsSize_t>` function or
:c:func:`calling <PyObject_CallMethod>` :meth:`int.to_bytes`.
The speedup is expected to be negligible for most users.
Exactly what values are considered compact is an implementation detail
and is subject to change.
.. c:function:: Py_ssize_t PyUnstable_Long_CompactValue(const PyLongObject* op)
If *op* is compact, as determined by :c:func:`PyUnstable_Long_IsCompact`,
return its value.
Otherwise, the return value is undefined.