cpython/Doc/c-api/long.rst

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.. highlightlang:: c
.. _longobjects:
Long Integer Objects
--------------------
.. index:: object: long integer
.. ctype:: PyLongObject
This subtype of :ctype:`PyObject` represents a Python long integer object.
.. cvar:: PyTypeObject PyLong_Type
.. index:: single: LongType (in modules types)
This instance of :ctype:`PyTypeObject` represents the Python long integer type.
This is the same object as ``long`` and ``types.LongType``.
.. cfunction:: int PyLong_Check(PyObject *p)
Return true if its argument is a :ctype:`PyLongObject` or a subtype of
:ctype:`PyLongObject`.
.. versionchanged:: 2.2
Allowed subtypes to be accepted.
.. cfunction:: int PyLong_CheckExact(PyObject *p)
Return true if its argument is a :ctype:`PyLongObject`, but not a subtype of
:ctype:`PyLongObject`.
.. versionadded:: 2.2
.. cfunction:: PyObject* PyLong_FromLong(long v)
Return a new :ctype:`PyLongObject` object from *v*, or *NULL* on failure.
.. cfunction:: PyObject* PyLong_FromUnsignedLong(unsigned long v)
Return a new :ctype:`PyLongObject` object from a C :ctype:`unsigned long`, or
*NULL* on failure.
.. cfunction:: PyObject* PyLong_FromLongLong(PY_LONG_LONG v)
Return a new :ctype:`PyLongObject` object from a C :ctype:`long long`, or *NULL*
on failure.
.. cfunction:: PyObject* PyLong_FromUnsignedLongLong(unsigned PY_LONG_LONG v)
Return a new :ctype:`PyLongObject` object from a C :ctype:`unsigned long long`,
or *NULL* on failure.
.. cfunction:: PyObject* PyLong_FromDouble(double v)
Return a new :ctype:`PyLongObject` object from the integer part of *v*, or
*NULL* on failure.
.. cfunction:: PyObject* PyLong_FromString(char *str, char **pend, int base)
Return a new :ctype:`PyLongObject` based on the string value in *str*, which is
interpreted according to the radix in *base*. If *pend* is non-*NULL*,
``*pend`` will point to the first character in *str* which follows the
representation of the number. If *base* is ``0``, the radix will be determined
based on the leading characters of *str*: if *str* starts with ``'0x'`` or
``'0X'``, radix 16 will be used; if *str* starts with ``'0'``, radix 8 will be
used; otherwise radix 10 will be used. If *base* is not ``0``, it must be
between ``2`` and ``36``, inclusive. Leading spaces are ignored. If there are
no digits, :exc:`ValueError` will be raised.
.. cfunction:: PyObject* PyLong_FromUnicode(Py_UNICODE *u, Py_ssize_t length, int base)
Convert a sequence of Unicode digits to a Python long integer value. The first
parameter, *u*, points to the first character of the Unicode string, *length*
gives the number of characters, and *base* is the radix for the conversion. The
radix must be in the range [2, 36]; if it is out of range, :exc:`ValueError`
will be raised.
.. versionadded:: 1.6
.. cfunction:: PyObject* PyLong_FromVoidPtr(void *p)
Create a Python integer or long integer from the pointer *p*. The pointer value
can be retrieved from the resulting value using :cfunc:`PyLong_AsVoidPtr`.
.. versionadded:: 1.5.2
.. versionchanged:: 2.5
If the integer is larger than LONG_MAX, a positive long integer is returned.
.. cfunction:: long PyLong_AsLong(PyObject *pylong)
.. index::
single: LONG_MAX
single: OverflowError (built-in exception)
Return a C :ctype:`long` representation of the contents of *pylong*. If
*pylong* is greater than :const:`LONG_MAX`, an :exc:`OverflowError` is raised.
.. cfunction:: unsigned long PyLong_AsUnsignedLong(PyObject *pylong)
.. index::
single: ULONG_MAX
single: OverflowError (built-in exception)
Return a C :ctype:`unsigned long` representation of the contents of *pylong*.
If *pylong* is greater than :const:`ULONG_MAX`, an :exc:`OverflowError` is
raised.
.. cfunction:: PY_LONG_LONG PyLong_AsLongLong(PyObject *pylong)
Return a C :ctype:`long long` from a Python long integer. If *pylong* cannot be
represented as a :ctype:`long long`, an :exc:`OverflowError` will be raised.
.. versionadded:: 2.2
.. cfunction:: unsigned PY_LONG_LONG PyLong_AsUnsignedLongLong(PyObject *pylong)
Return a C :ctype:`unsigned long long` from a Python long integer. If *pylong*
cannot be represented as an :ctype:`unsigned long long`, an :exc:`OverflowError`
will be raised if the value is positive, or a :exc:`TypeError` will be raised if
the value is negative.
.. versionadded:: 2.2
.. cfunction:: unsigned long PyLong_AsUnsignedLongMask(PyObject *io)
Return a C :ctype:`unsigned long` from a Python long integer, without checking
for overflow.
.. versionadded:: 2.3
.. cfunction:: unsigned PY_LONG_LONG PyLong_AsUnsignedLongLongMask(PyObject *io)
Return a C :ctype:`unsigned long long` from a Python long integer, without
checking for overflow.
.. versionadded:: 2.3
.. cfunction:: double PyLong_AsDouble(PyObject *pylong)
Return a C :ctype:`double` representation of the contents of *pylong*. If
*pylong* cannot be approximately represented as a :ctype:`double`, an
:exc:`OverflowError` exception is raised and ``-1.0`` will be returned.
.. cfunction:: void* PyLong_AsVoidPtr(PyObject *pylong)
Convert a Python integer or long integer *pylong* to a C :ctype:`void` pointer.
If *pylong* cannot be converted, an :exc:`OverflowError` will be raised. This
is only assured to produce a usable :ctype:`void` pointer for values created
with :cfunc:`PyLong_FromVoidPtr`.
.. versionadded:: 1.5.2
.. versionchanged:: 2.5
For values outside 0..LONG_MAX, both signed and unsigned integers are acccepted.