
String/Bytes Objects
********************

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

Note: These functions have been renamed to PyBytes_* in Python 3.x. Unless
  otherwise noted, the PyBytes functions available in 3.x are aliased
  to their PyString_* equivalents to help porting.

PyStringObject

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

PyTypeObject PyString_Type

   This instance of ``PyTypeObject`` represents the Python string
   type; it is the same object as ``str`` and ``types.StringType`` in
   the Python layer. .

int PyString_Check(PyObject *o)

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

   Changed in version 2.2: Allowed subtypes to be accepted.

int PyString_CheckExact(PyObject *o)

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

   New in version 2.2.

PyObject* PyString_FromString(const char *v)
    Return value: New reference.

   Return a new string 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* PyString_FromStringAndSize(const char *v, Py_ssize_t len)
    Return value: New reference.

   Return a new string 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 string are uninitialized.

   Changed in version 2.5: This function used an ``int`` type for
   *len*. This might require changes in your code for properly
   supporting 64-bit systems.

PyObject* PyString_FromFormat(const char *format, ...)
    Return value: New reference.

   Take a C ``printf()``-style *format* string and a variable number
   of arguments, calculate the size of the resulting Python string and
   return a string 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* PyString_FromFormatV(const char *format, va_list vargs)
    Return value: New reference.

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

Py_ssize_t PyString_Size(PyObject *string)

   Return the length of the string in string object *string*.

   Changed in version 2.5: This function returned an ``int`` type.
   This might require changes in your code for properly supporting
   64-bit systems.

Py_ssize_t PyString_GET_SIZE(PyObject *string)

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

   Changed in version 2.5: This macro returned an ``int`` type. This
   might require changes in your code for properly supporting 64-bit
   systems.

char* PyString_AsString(PyObject *string)

   Return a NUL-terminated representation of the contents of *string*.
   The pointer refers to the internal buffer of *string*, not a copy.
   The data must not be modified in any way, unless the string was
   just created using ``PyString_FromStringAndSize(NULL, size)``. It
   must not be deallocated.  If *string* is a Unicode object, this
   function computes the default encoding of *string* and operates on
   that.  If *string* is not a string object at all,
   ``PyString_AsString()`` returns *NULL* and raises ``TypeError``.

char* PyString_AS_STRING(PyObject *string)

   Macro form of ``PyString_AsString()`` but without error checking.
   Only string objects are supported; no Unicode objects should be
   passed.

int PyString_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*.

   The function accepts both string and Unicode objects as input. For
   Unicode objects it returns the default encoded version of the
   object.  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 ``PyString_FromStringAndSize(NULL, size)``.
   It must not be deallocated.  If *string* is a Unicode object, this
   function computes the default encoding of *string* and operates on
   that.  If *string* is not a string object at all,
   ``PyString_AsStringAndSize()`` returns ``-1`` and raises
   ``TypeError``.

   Changed in version 2.5: This function used an ``int *`` type for
   *length*. This might require changes in your code for properly
   supporting 64-bit systems.

void PyString_Concat(PyObject **string, PyObject *newpart)

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

void PyString_ConcatAndDel(PyObject **string, PyObject *newpart)

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

int _PyString_Resize(PyObject **string, Py_ssize_t newsize)

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

   Changed in version 2.5: This function used an ``int`` type for
   *newsize*. This might require changes in your code for properly
   supporting 64-bit systems.

PyObject* PyString_Format(PyObject *format, PyObject *args)
    Return value: New reference.

   Return a new string object from *format* and *args*. Analogous to
   ``format % args``.  The *args* argument must be a tuple.

void PyString_InternInPlace(PyObject **string)

   Intern the argument **string* in place.  The argument must be the
   address of a pointer variable pointing to a Python string object.
   If there is an existing interned string that is the same as
   **string*, it sets **string* to it (decrementing the reference
   count of the old string object and incrementing the reference count
   of the interned string object), otherwise it leaves **string* alone
   and interns it (incrementing its reference count).  (Clarification:
   even though there is a lot of talk about reference counts, think of
   this function as reference-count-neutral; you own the object after
   the call if and only if you owned it before the call.)

   Note: This function is not available in 3.x and does not have a PyBytes
     alias.

PyObject* PyString_InternFromString(const char *v)
    Return value: New reference.

   A combination of ``PyString_FromString()`` and
   ``PyString_InternInPlace()``, returning either a new string object
   that has been interned, or a new ("owned") reference to an earlier
   interned string object with the same value.

   Note: This function is not available in 3.x and does not have a PyBytes
     alias.

PyObject* PyString_Decode(const char *s, Py_ssize_t size, const char *encoding, const char *errors)
    Return value: New reference.

   Create an object by decoding *size* bytes of the encoded buffer *s*
   using the codec registered for *encoding*.  *encoding* and *errors*
   have the same meaning as the parameters of the same name in the
   ``unicode()`` built-in function. The codec to be used is looked up
   using the Python codec registry.  Return *NULL* if an exception was
   raised by the codec.

   Note: This function is not available in 3.x and does not have a PyBytes
     alias.

   Changed in version 2.5: This function used an ``int`` type for
   *size*. This might require changes in your code for properly
   supporting 64-bit systems.

PyObject* PyString_AsDecodedObject(PyObject *str, const char *encoding, const char *errors)
    Return value: New reference.

   Decode a string object by passing it to the codec registered for
   *encoding* and return the result as Python object. *encoding* and
   *errors* have the same meaning as the parameters of the same name
   in the string ``encode()`` method. The codec to be used is looked
   up using the Python codec registry. Return *NULL* if an exception
   was raised by the codec.

   Note: This function is not available in 3.x and does not have a PyBytes
     alias.

PyObject* PyString_Encode(const char *s, Py_ssize_t size, const char *encoding, const char *errors)
    Return value: New reference.

   Encode the ``char`` buffer of the given size by passing it to the
   codec registered for *encoding* and return a Python object.
   *encoding* and *errors* have the same meaning as the parameters of
   the same name in the string ``encode()`` method. The codec to be
   used is looked up using the Python codec registry.  Return *NULL*
   if an exception was raised by the codec.

   Note: This function is not available in 3.x and does not have a PyBytes
     alias.

   Changed in version 2.5: This function used an ``int`` type for
   *size*. This might require changes in your code for properly
   supporting 64-bit systems.

PyObject* PyString_AsEncodedObject(PyObject *str, const char *encoding, const char *errors)
    Return value: New reference.

   Encode a string object using the codec registered for *encoding*
   and return the result as Python object. *encoding* and *errors*
   have the same meaning as the parameters of the same name in the
   string ``encode()`` method. The codec to be used is looked up using
   the Python codec registry. Return *NULL* if an exception was raised
   by the codec.

   Note: This function is not available in 3.x and does not have a PyBytes
     alias.
