summaryrefslogtreecommitdiffstats
path: root/Doc/c-api/long.rst
blob: f592cb65c3e3a9184ff1849b98588c95bc658130 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
.. highlightlang:: c

.. _longobjects:

Integer Objects
---------------

.. index:: object: long integer
           object: integer

All integers are implemented as "long" integer objects of arbitrary size.

.. 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`.


.. 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`.


.. 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. So it should be possible to
   change the value of ``1``.  I suspect the behaviour of Python in this case is
   undefined. :-)


.. c:function:: PyObject* PyLong_FromUnsignedLong(unsigned long v)

   Return a new :c:type:`PyLongObject` object from a C :c:type:`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:type:`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:type:`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*.  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 ``'0o'`` or
   ``'0O'``, radix 8 will be used; if *str* starts with ``'0b'`` or ``'0B'``,
   radix 2 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.


.. c:function:: PyObject* PyLong_FromUnicode(Py_UNICODE *u, Py_ssize_t length, int base)

   Convert a sequence of Unicode digits to a Python integer value.  The Unicode
   string is first encoded to a byte string using :c:func:`PyUnicode_EncodeDecimal`
   and then converted using :c:func:`PyLong_FromString`.

   .. deprecated-removed:: 3.3 4.0
      Part of the old-style :c:type:`Py_UNICODE` API; please migrate to using
      :c:func:`PyLong_FromUnicodeObject`.


.. c:function:: PyObject* PyLong_FromUnicodeObject(PyObject *u, int base)

   Convert a sequence of Unicode digits in the string *u* to a Python integer
   value.  The Unicode string is first encoded to a byte string using
   :c:func:`PyUnicode_EncodeDecimal` and then converted using
   :c:func:`PyLong_FromString`.

   .. 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:type:`long` representation of *obj*.  If *obj* is not an
   instance of :c:type:`PyLongObject`, first call its :meth:`__int__` 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:type:`long`.


.. c:function:: long PyLong_AsLongAndOverflow(PyObject *obj, int *overflow)

   Return a C :c:type:`long` representation of *obj*.  If *obj* is not an
   instance of :c:type:`PyLongObject`, first call its :meth:`__int__` 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.


.. c:function:: long long PyLong_AsLongLong(PyObject *obj)

   .. index::
      single: OverflowError (built-in exception)

   Return a C :c:type:`long long` representation of *obj*.  If *obj* is not an
   instance of :c:type:`PyLongObject`, first call its :meth:`__int__` 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:type:`long`.


.. c:function:: long long PyLong_AsLongLongAndOverflow(PyObject *obj, int *overflow)

   Return a C :c:type:`long long` representation of *obj*.  If *obj* is not an
   instance of :c:type:`PyLongObject`, first call its :meth:`__int__` method
   (if present) to convert it to a :c:type:`PyLongObject`.

   If the value of *obj* is greater than :const:`PY_LLONG_MAX` or less than
   :const:`PY_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.

   .. versionadded:: 3.2


.. 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`.


.. c:function:: unsigned long PyLong_AsUnsignedLong(PyObject *pylong)

   .. index::
      single: ULONG_MAX
      single: OverflowError (built-in exception)

   Return a C :c:type:`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:type:`unsigned long`.


.. c:function:: size_t PyLong_AsSize_t(PyObject *pylong)

   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`.


.. c:function:: unsigned long long PyLong_AsUnsignedLongLong(PyObject *pylong)

   .. index::
      single: OverflowError (built-in exception)

   Return a C :c:type:`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:type:`unsigned long long`.

   .. 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:type:`unsigned long` representation of *obj*.  If *obj*
   is not an instance of :c:type:`PyLongObject`, first call its :meth:`__int__`
   method (if present) to convert it to a :c:type:`PyLongObject`.

   If the value of *obj* is out of range for an :c:type:`unsigned long`,
   return the reduction of that value modulo ``ULONG_MAX + 1``.


.. c:function:: unsigned long long PyLong_AsUnsignedLongLongMask(PyObject *obj)

   Return a C :c:type:`unsigned long long` representation of *obj*.  If *obj*
   is not an instance of :c:type:`PyLongObject`, first call its :meth:`__int__`
   method (if present) to convert it to a :c:type:`PyLongObject`.

   If the value of *obj* is out of range for an :c:type:`unsigned long long`,
   return the reduction of that value modulo ``PY_ULLONG_MAX + 1``.


.. c:function:: double PyLong_AsDouble(PyObject *pylong)

   Return a C :c:type:`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:type:`double`.


.. c:function:: void* PyLong_AsVoidPtr(PyObject *pylong)

   Convert a Python integer *pylong* to a C :c:type:`void` pointer.
   If *pylong* cannot be converted, an :exc:`OverflowError` will be raised.  This
   is only assured to produce a usable :c:type:`void` pointer for values created
   with :c:func:`PyLong_FromVoidPtr`.