
Bytes Objects
*************

These functions raise ``TypeError`` when expecting a bytes parameter
and are called with a non-bytes parameter.

PyBytesObject

   This subtype of ``PyObject`` represents a Python bytes object.

PyTypeObject PyBytes_Type

   This instance of ``PyTypeObject`` represents the Python bytes type;
   it is the same object as ``bytes`` in the Python layer.

int PyBytes_Check(PyObject *o)

   Return true if the object *o* is a bytes object or an instance of a
   subtype of the bytes type.

int PyBytes_CheckExact(PyObject *o)

   Return true if the object *o* is a bytes object, but not an
   instance of a subtype of the bytes type.

PyObject* PyBytes_FromString(const char *v)

   Return a new bytes object with a copy of the string *v* as value on
   success, and *NULL* on failure.  The parameter *v* must not be
   *NULL*; it will not be checked.

PyObject* PyBytes_FromStringAndSize(const char *v, Py_ssize_t len)

   Return a new bytes object with a copy of the string *v* as value
   and length *len* on success, and *NULL* on failure.  If *v* is
   *NULL*, the contents of the bytes object are uninitialized.

PyObject* PyBytes_FromFormat(const char *format, ...)

   Take a C ``printf()``-style *format* string and a variable number
   of arguments, calculate the size of the resulting Python bytes
   object and return a bytes object with the values formatted into it.
   The variable arguments must be C types and must correspond exactly
   to the format characters in the *format* string.  The following
   format characters are allowed:

   +---------------------+-----------------+----------------------------------+
   | Format Characters   | Type            | Comment                          |
   +=====================+=================+==================================+
   | ``%%``              | *n/a*           | The literal % character.         |
   +---------------------+-----------------+----------------------------------+
   | ``%c``              | int             | A single character, represented  |
   |                     |                 | as an C int.                     |
   +---------------------+-----------------+----------------------------------+
   | ``%d``              | int             | Exactly equivalent to            |
   |                     |                 | ``printf("%d")``.                |
   +---------------------+-----------------+----------------------------------+
   | ``%u``              | unsigned int    | Exactly equivalent to            |
   |                     |                 | ``printf("%u")``.                |
   +---------------------+-----------------+----------------------------------+
   | ``%ld``             | long            | Exactly equivalent to            |
   |                     |                 | ``printf("%ld")``.               |
   +---------------------+-----------------+----------------------------------+
   | ``%lu``             | unsigned long   | Exactly equivalent to            |
   |                     |                 | ``printf("%lu")``.               |
   +---------------------+-----------------+----------------------------------+
   | ``%zd``             | Py_ssize_t      | Exactly equivalent to            |
   |                     |                 | ``printf("%zd")``.               |
   +---------------------+-----------------+----------------------------------+
   | ``%zu``             | size_t          | Exactly equivalent to            |
   |                     |                 | ``printf("%zu")``.               |
   +---------------------+-----------------+----------------------------------+
   | ``%i``              | int             | Exactly equivalent to            |
   |                     |                 | ``printf("%i")``.                |
   +---------------------+-----------------+----------------------------------+
   | ``%x``              | int             | Exactly equivalent to            |
   |                     |                 | ``printf("%x")``.                |
   +---------------------+-----------------+----------------------------------+
   | ``%s``              | char*           | A null-terminated C character    |
   |                     |                 | array.                           |
   +---------------------+-----------------+----------------------------------+
   | ``%p``              | void*           | The hex representation of a C    |
   |                     |                 | pointer. Mostly equivalent to    |
   |                     |                 | ``printf("%p")`` except that it  |
   |                     |                 | is guaranteed to start with the  |
   |                     |                 | literal ``0x`` regardless of     |
   |                     |                 | what the platform's ``printf``   |
   |                     |                 | yields.                          |
   +---------------------+-----------------+----------------------------------+

   An unrecognized format character causes all the rest of the format
   string to be copied as-is to the result string, and any extra
   arguments discarded.

PyObject* PyBytes_FromFormatV(const char *format, va_list vargs)

   Identical to ``PyBytes_FromFormat()`` except that it takes exactly
   two arguments.

PyObject* PyBytes_FromObject(PyObject *o)

   Return the bytes representation of object *o* that implements the
   buffer protocol.

Py_ssize_t PyBytes_Size(PyObject *o)

   Return the length of the bytes in bytes object *o*.

Py_ssize_t PyBytes_GET_SIZE(PyObject *o)

   Macro form of ``PyBytes_Size()`` but without error checking.

char* PyBytes_AsString(PyObject *o)

   Return a NUL-terminated representation of the contents of *o*.  The
   pointer refers to the internal buffer of *o*, not a copy.  The data
   must not be modified in any way, unless the string was just created
   using ``PyBytes_FromStringAndSize(NULL, size)``. It must not be
   deallocated.  If *o* is not a string object at all,
   ``PyBytes_AsString()`` returns *NULL* and raises ``TypeError``.

char* PyBytes_AS_STRING(PyObject *string)

   Macro form of ``PyBytes_AsString()`` but without error checking.

int PyBytes_AsStringAndSize(PyObject *obj, char **buffer, Py_ssize_t *length)

   Return a NUL-terminated representation of the contents of the
   object *obj* through the output variables *buffer* and *length*.

   If *length* is *NULL*, the resulting buffer may not contain NUL
   characters; if it does, the function returns ``-1`` and a
   ``TypeError`` is raised.

   The buffer refers to an internal string buffer of *obj*, not a
   copy. The data must not be modified in any way, unless the string
   was just created using ``PyBytes_FromStringAndSize(NULL, size)``.
   It must not be deallocated.  If *string* is not a string object at
   all, ``PyBytes_AsStringAndSize()`` returns ``-1`` and raises
   ``TypeError``.

void PyBytes_Concat(PyObject **bytes, PyObject *newpart)

   Create a new bytes object in **bytes* containing the contents of
   *newpart* appended to *bytes*; the caller will own the new
   reference.  The reference to the old value of *bytes* will be
   stolen.  If the new string cannot be created, the old reference to
   *bytes* will still be discarded and the value of **bytes* will be
   set to *NULL*; the appropriate exception will be set.

void PyBytes_ConcatAndDel(PyObject **bytes, PyObject *newpart)

   Create a new string object in **bytes* containing the contents of
   *newpart* appended to *bytes*.  This version decrements the
   reference count of *newpart*.

int _PyBytes_Resize(PyObject **bytes, Py_ssize_t newsize)

   A way to resize a bytes object even though it is "immutable". Only
   use this to build up a brand new bytes object; don't use this if
   the bytes may already be known in other parts of the code.  It is
   an error to call this function if the refcount on the input bytes
   object is not one. Pass the address of an existing bytes object as
   an lvalue (it may be written into), and the new size desired.  On
   success, **bytes* holds the resized bytes object and ``0`` is
   returned; the address in **bytes* may differ from its input value.
   If the reallocation fails, the original bytes object at **bytes* is
   deallocated, **bytes* is set to *NULL*, a memory exception is set,
   and ``-1`` is returned.
