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+.. highlightlang:: c
+
+.. _unicodeobjects:
+
+Unicode Objects and Codecs
+--------------------------
+
+.. sectionauthor:: Marc-Andre Lemburg <mal@lemburg.com>
+
+Unicode Objects
+^^^^^^^^^^^^^^^
+
+These are the basic Unicode object types used for the Unicode implementation in
+Python:
+
+.. % --- Unicode Type -------------------------------------------------------
+
+
+.. ctype:: Py_UNICODE
+
+ This type represents the storage type which is used by Python internally as
+ basis for holding Unicode ordinals. Python's default builds use a 16-bit type
+ for :ctype:`Py_UNICODE` and store Unicode values internally as UCS2. It is also
+ possible to build a UCS4 version of Python (most recent Linux distributions come
+ with UCS4 builds of Python). These builds then use a 32-bit type for
+ :ctype:`Py_UNICODE` and store Unicode data internally as UCS4. On platforms
+ where :ctype:`wchar_t` is available and compatible with the chosen Python
+ Unicode build variant, :ctype:`Py_UNICODE` is a typedef alias for
+ :ctype:`wchar_t` to enhance native platform compatibility. On all other
+ platforms, :ctype:`Py_UNICODE` is a typedef alias for either :ctype:`unsigned
+ short` (UCS2) or :ctype:`unsigned long` (UCS4).
+
+Note that UCS2 and UCS4 Python builds are not binary compatible. Please keep
+this in mind when writing extensions or interfaces.
+
+
+.. ctype:: PyUnicodeObject
+
+ This subtype of :ctype:`PyObject` represents a Python Unicode object.
+
+
+.. cvar:: PyTypeObject PyUnicode_Type
+
+ This instance of :ctype:`PyTypeObject` represents the Python Unicode type. It
+ is exposed to Python code as ``str``.
+
+The following APIs are really C macros and can be used to do fast checks and to
+access internal read-only data of Unicode objects:
+
+
+.. cfunction:: int PyUnicode_Check(PyObject *o)
+
+ Return true if the object *o* is a Unicode object or an instance of a Unicode
+ subtype.
+
+
+.. cfunction:: int PyUnicode_CheckExact(PyObject *o)
+
+ Return true if the object *o* is a Unicode object, but not an instance of a
+ subtype.
+
+
+.. cfunction:: Py_ssize_t PyUnicode_GET_SIZE(PyObject *o)
+
+ Return the size of the object. *o* has to be a :ctype:`PyUnicodeObject` (not
+ checked).
+
+
+.. cfunction:: Py_ssize_t PyUnicode_GET_DATA_SIZE(PyObject *o)
+
+ Return the size of the object's internal buffer in bytes. *o* has to be a
+ :ctype:`PyUnicodeObject` (not checked).
+
+
+.. cfunction:: Py_UNICODE* PyUnicode_AS_UNICODE(PyObject *o)
+
+ Return a pointer to the internal :ctype:`Py_UNICODE` buffer of the object. *o*
+ has to be a :ctype:`PyUnicodeObject` (not checked).
+
+
+.. cfunction:: const char* PyUnicode_AS_DATA(PyObject *o)
+
+ Return a pointer to the internal buffer of the object. *o* has to be a
+ :ctype:`PyUnicodeObject` (not checked).
+
+Unicode provides many different character properties. The most often needed ones
+are available through these macros which are mapped to C functions depending on
+the Python configuration.
+
+.. % --- Unicode character properties ---------------------------------------
+
+
+.. cfunction:: int Py_UNICODE_ISSPACE(Py_UNICODE ch)
+
+ Return 1 or 0 depending on whether *ch* is a whitespace character.
+
+
+.. cfunction:: int Py_UNICODE_ISLOWER(Py_UNICODE ch)
+
+ Return 1 or 0 depending on whether *ch* is a lowercase character.
+
+
+.. cfunction:: int Py_UNICODE_ISUPPER(Py_UNICODE ch)
+
+ Return 1 or 0 depending on whether *ch* is an uppercase character.
+
+
+.. cfunction:: int Py_UNICODE_ISTITLE(Py_UNICODE ch)
+
+ Return 1 or 0 depending on whether *ch* is a titlecase character.
+
+
+.. cfunction:: int Py_UNICODE_ISLINEBREAK(Py_UNICODE ch)
+
+ Return 1 or 0 depending on whether *ch* is a linebreak character.
+
+
+.. cfunction:: int Py_UNICODE_ISDECIMAL(Py_UNICODE ch)
+
+ Return 1 or 0 depending on whether *ch* is a decimal character.
+
+
+.. cfunction:: int Py_UNICODE_ISDIGIT(Py_UNICODE ch)
+
+ Return 1 or 0 depending on whether *ch* is a digit character.
+
+
+.. cfunction:: int Py_UNICODE_ISNUMERIC(Py_UNICODE ch)
+
+ Return 1 or 0 depending on whether *ch* is a numeric character.
+
+
+.. cfunction:: int Py_UNICODE_ISALPHA(Py_UNICODE ch)
+
+ Return 1 or 0 depending on whether *ch* is an alphabetic character.
+
+
+.. cfunction:: int Py_UNICODE_ISALNUM(Py_UNICODE ch)
+
+ Return 1 or 0 depending on whether *ch* is an alphanumeric character.
+
+These APIs can be used for fast direct character conversions:
+
+
+.. cfunction:: Py_UNICODE Py_UNICODE_TOLOWER(Py_UNICODE ch)
+
+ Return the character *ch* converted to lower case.
+
+
+.. cfunction:: Py_UNICODE Py_UNICODE_TOUPPER(Py_UNICODE ch)
+
+ Return the character *ch* converted to upper case.
+
+
+.. cfunction:: Py_UNICODE Py_UNICODE_TOTITLE(Py_UNICODE ch)
+
+ Return the character *ch* converted to title case.
+
+
+.. cfunction:: int Py_UNICODE_TODECIMAL(Py_UNICODE ch)
+
+ Return the character *ch* converted to a decimal positive integer. Return
+ ``-1`` if this is not possible. This macro does not raise exceptions.
+
+
+.. cfunction:: int Py_UNICODE_TODIGIT(Py_UNICODE ch)
+
+ Return the character *ch* converted to a single digit integer. Return ``-1`` if
+ this is not possible. This macro does not raise exceptions.
+
+
+.. cfunction:: double Py_UNICODE_TONUMERIC(Py_UNICODE ch)
+
+ Return the character *ch* converted to a double. Return ``-1.0`` if this is not
+ possible. This macro does not raise exceptions.
+
+To create Unicode objects and access their basic sequence properties, use these
+APIs:
+
+.. % --- Plain Py_UNICODE ---------------------------------------------------
+
+
+.. cfunction:: PyObject* PyUnicode_FromUnicode(const Py_UNICODE *u, Py_ssize_t size)
+
+ Create a Unicode Object from the Py_UNICODE buffer *u* of the given size. *u*
+ may be *NULL* which causes the contents to be undefined. It is the user's
+ responsibility to fill in the needed data. The buffer is copied into the new
+ object. If the buffer is not *NULL*, the return value might be a shared object.
+ Therefore, modification of the resulting Unicode object is only allowed when *u*
+ is *NULL*.
+
+
+.. cfunction:: PyObject* PyUnicode_FromStringAndSize(const char *u, Py_ssize_t size)
+
+ Create a Unicode Object from the char buffer *u*. The bytes will be interpreted
+ as being UTF-8 encoded. *u* may also be *NULL* which
+ causes the contents to be undefined. It is the user's responsibility to fill in
+ the needed data. The buffer is copied into the new object. If the buffer is not
+ *NULL*, the return value might be a shared object. Therefore, modification of
+ the resulting Unicode object is only allowed when *u* is *NULL*.
+
+
+.. cfunction:: PyObject *PyUnicode_FromString(const char *u)
+
+ Create a Unicode object from an UTF-8 encoded null-terminated char buffer
+ *u*.
+
+
+.. cfunction:: PyObject* PyUnicode_FromFormat(const char *format, ...)
+
+ Take a C :cfunc:`printf`\ -style *format* string and a variable number of
+ arguments, calculate the size of the resulting Python unicode 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:
+
+ .. % The descriptions for %zd and %zu are wrong, but the truth is complicated
+ .. % because not all compilers support the %z width modifier -- we fake it
+ .. % when necessary via interpolating PY_FORMAT_SIZE_T.
+
+ +-------------------+---------------------+--------------------------------+
+ | Format Characters | Type | Comment |
+ +===================+=====================+================================+
+ | :attr:`%%` | *n/a* | The literal % character. |
+ +-------------------+---------------------+--------------------------------+
+ | :attr:`%c` | int | A single character, |
+ | | | represented as an C int. |
+ +-------------------+---------------------+--------------------------------+
+ | :attr:`%d` | int | Exactly equivalent to |
+ | | | ``printf("%d")``. |
+ +-------------------+---------------------+--------------------------------+
+ | :attr:`%u` | unsigned int | Exactly equivalent to |
+ | | | ``printf("%u")``. |
+ +-------------------+---------------------+--------------------------------+
+ | :attr:`%ld` | long | Exactly equivalent to |
+ | | | ``printf("%ld")``. |
+ +-------------------+---------------------+--------------------------------+
+ | :attr:`%lu` | unsigned long | Exactly equivalent to |
+ | | | ``printf("%lu")``. |
+ +-------------------+---------------------+--------------------------------+
+ | :attr:`%zd` | Py_ssize_t | Exactly equivalent to |
+ | | | ``printf("%zd")``. |
+ +-------------------+---------------------+--------------------------------+
+ | :attr:`%zu` | size_t | Exactly equivalent to |
+ | | | ``printf("%zu")``. |
+ +-------------------+---------------------+--------------------------------+
+ | :attr:`%i` | int | Exactly equivalent to |
+ | | | ``printf("%i")``. |
+ +-------------------+---------------------+--------------------------------+
+ | :attr:`%x` | int | Exactly equivalent to |
+ | | | ``printf("%x")``. |
+ +-------------------+---------------------+--------------------------------+
+ | :attr:`%s` | char\* | A null-terminated C character |
+ | | | array. |
+ +-------------------+---------------------+--------------------------------+
+ | :attr:`%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. |
+ +-------------------+---------------------+--------------------------------+
+ | :attr:`%U` | PyObject\* | A unicode object. |
+ +-------------------+---------------------+--------------------------------+
+ | :attr:`%V` | PyObject\*, char \* | A unicode object (which may be |
+ | | | *NULL*) and a null-terminated |
+ | | | C character array as a second |
+ | | | parameter (which will be used, |
+ | | | if the first parameter is |
+ | | | *NULL*). |
+ +-------------------+---------------------+--------------------------------+
+ | :attr:`%S` | PyObject\* | The result of calling |
+ | | | :func:`PyObject_Unicode`. |
+ +-------------------+---------------------+--------------------------------+
+ | :attr:`%R` | PyObject\* | The result of calling |
+ | | | :func:`PyObject_Repr`. |
+ +-------------------+---------------------+--------------------------------+
+
+ 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.
+
+
+.. cfunction:: PyObject* PyUnicode_FromFormatV(const char *format, va_list vargs)
+
+ Identical to :func:`PyUnicode_FromFormat` except that it takes exactly two
+ arguments.
+
+
+.. cfunction:: Py_UNICODE* PyUnicode_AsUnicode(PyObject *unicode)
+
+ Return a read-only pointer to the Unicode object's internal :ctype:`Py_UNICODE`
+ buffer, *NULL* if *unicode* is not a Unicode object.
+
+
+.. cfunction:: Py_ssize_t PyUnicode_GetSize(PyObject *unicode)
+
+ Return the length of the Unicode object.
+
+
+.. cfunction:: PyObject* PyUnicode_FromEncodedObject(PyObject *obj, const char *encoding, const char *errors)
+
+ Coerce an encoded object *obj* to an Unicode object and return a reference with
+ incremented refcount.
+
+ String and other char buffer compatible objects are decoded according to the
+ given encoding and using the error handling defined by errors. Both can be
+ *NULL* to have the interface use the default values (see the next section for
+ details).
+
+ All other objects, including Unicode objects, cause a :exc:`TypeError` to be
+ set.
+
+ The API returns *NULL* if there was an error. The caller is responsible for
+ decref'ing the returned objects.
+
+
+.. cfunction:: PyObject* PyUnicode_FromObject(PyObject *obj)
+
+ Shortcut for ``PyUnicode_FromEncodedObject(obj, NULL, "strict")`` which is used
+ throughout the interpreter whenever coercion to Unicode is needed.
+
+If the platform supports :ctype:`wchar_t` and provides a header file wchar.h,
+Python can interface directly to this type using the following functions.
+Support is optimized if Python's own :ctype:`Py_UNICODE` type is identical to
+the system's :ctype:`wchar_t`.
+
+.. % --- wchar_t support for platforms which support it ---------------------
+
+
+.. cfunction:: PyObject* PyUnicode_FromWideChar(const wchar_t *w, Py_ssize_t size)
+
+ Create a Unicode object from the :ctype:`wchar_t` buffer *w* of the given size.
+ Return *NULL* on failure.
+
+
+.. cfunction:: Py_ssize_t PyUnicode_AsWideChar(PyUnicodeObject *unicode, wchar_t *w, Py_ssize_t size)
+
+ Copy the Unicode object contents into the :ctype:`wchar_t` buffer *w*. At most
+ *size* :ctype:`wchar_t` characters are copied (excluding a possibly trailing
+ 0-termination character). Return the number of :ctype:`wchar_t` characters
+ copied or -1 in case of an error. Note that the resulting :ctype:`wchar_t`
+ string may or may not be 0-terminated. It is the responsibility of the caller
+ to make sure that the :ctype:`wchar_t` string is 0-terminated in case this is
+ required by the application.
+
+
+.. _builtincodecs:
+
+Built-in Codecs
+^^^^^^^^^^^^^^^
+
+Python provides a set of builtin codecs which are written in C for speed. All of
+these codecs are directly usable via the following functions.
+
+Many of the following APIs take two arguments encoding and errors. These
+parameters encoding and errors have the same semantics as the ones of the
+builtin unicode() Unicode object constructor.
+
+Setting encoding to *NULL* causes the default encoding to be used which is
+ASCII. The file system calls should use :cdata:`Py_FileSystemDefaultEncoding`
+as the encoding for file names. This variable should be treated as read-only: On
+some systems, it will be a pointer to a static string, on others, it will change
+at run-time (such as when the application invokes setlocale).
+
+Error handling is set by errors which may also be set to *NULL* meaning to use
+the default handling defined for the codec. Default error handling for all
+builtin codecs is "strict" (:exc:`ValueError` is raised).
+
+The codecs all use a similar interface. Only deviation from the following
+generic ones are documented for simplicity.
+
+These are the generic codec APIs:
+
+.. % --- Generic Codecs -----------------------------------------------------
+
+
+.. cfunction:: PyObject* PyUnicode_Decode(const char *s, Py_ssize_t size, const char *encoding, const char *errors)
+
+ Create a Unicode object by decoding *size* bytes of the encoded string *s*.
+ *encoding* and *errors* have the same meaning as the parameters of the same name
+ in the :func:`unicode` builtin function. The codec to be used is looked up
+ using the Python codec registry. Return *NULL* if an exception was raised by
+ the codec.
+
+
+.. cfunction:: PyObject* PyUnicode_Encode(const Py_UNICODE *s, Py_ssize_t size, const char *encoding, const char *errors)
+
+ Encode the :ctype:`Py_UNICODE` buffer of the given size and return a Python
+ string object. *encoding* and *errors* have the same meaning as the parameters
+ of the same name in the Unicode :meth:`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.
+
+
+.. cfunction:: PyObject* PyUnicode_AsEncodedString(PyObject *unicode, const char *encoding, const char *errors)
+
+ Encode a Unicode object and return the result as Python string object.
+ *encoding* and *errors* have the same meaning as the parameters of the same name
+ in the Unicode :meth:`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.
+
+These are the UTF-8 codec APIs:
+
+.. % --- UTF-8 Codecs -------------------------------------------------------
+
+
+.. cfunction:: PyObject* PyUnicode_DecodeUTF8(const char *s, Py_ssize_t size, const char *errors)
+
+ Create a Unicode object by decoding *size* bytes of the UTF-8 encoded string
+ *s*. Return *NULL* if an exception was raised by the codec.
+
+
+.. cfunction:: PyObject* PyUnicode_DecodeUTF8Stateful(const char *s, Py_ssize_t size, const char *errors, Py_ssize_t *consumed)
+
+ If *consumed* is *NULL*, behave like :cfunc:`PyUnicode_DecodeUTF8`. If
+ *consumed* is not *NULL*, trailing incomplete UTF-8 byte sequences will not be
+ treated as an error. Those bytes will not be decoded and the number of bytes
+ that have been decoded will be stored in *consumed*.
+
+
+.. cfunction:: PyObject* PyUnicode_EncodeUTF8(const Py_UNICODE *s, Py_ssize_t size, const char *errors)
+
+ Encode the :ctype:`Py_UNICODE` buffer of the given size using UTF-8 and return a
+ Python string object. Return *NULL* if an exception was raised by the codec.
+
+
+.. cfunction:: PyObject* PyUnicode_AsUTF8String(PyObject *unicode)
+
+ Encode a Unicode object using UTF-8 and return the result as Python string
+ object. Error handling is "strict". Return *NULL* if an exception was raised
+ by the codec.
+
+These are the UTF-32 codec APIs:
+
+.. % --- UTF-32 Codecs ------------------------------------------------------ */
+
+
+.. cfunction:: PyObject* PyUnicode_DecodeUTF32(const char *s, Py_ssize_t size, const char *errors, int *byteorder)
+
+ Decode *length* bytes from a UTF-32 encoded buffer string and return the
+ corresponding Unicode object. *errors* (if non-*NULL*) defines the error
+ handling. It defaults to "strict".
+
+ If *byteorder* is non-*NULL*, the decoder starts decoding using the given byte
+ order::
+
+ *byteorder == -1: little endian
+ *byteorder == 0: native order
+ *byteorder == 1: big endian
+
+ and then switches if the first four bytes of the input data are a byte order mark
+ (BOM) and the specified byte order is native order. This BOM is not copied into
+ the resulting Unicode string. After completion, *\*byteorder* is set to the
+ current byte order at the end of input data.
+
+ In a narrow build codepoints outside the BMP will be decoded as surrogate pairs.
+
+ If *byteorder* is *NULL*, the codec starts in native order mode.
+
+ Return *NULL* if an exception was raised by the codec.
+
+
+.. cfunction:: PyObject* PyUnicode_DecodeUTF32Stateful(const char *s, Py_ssize_t size, const char *errors, int *byteorder, Py_ssize_t *consumed)
+
+ If *consumed* is *NULL*, behave like :cfunc:`PyUnicode_DecodeUTF32`. If
+ *consumed* is not *NULL*, :cfunc:`PyUnicode_DecodeUTF32Stateful` will not treat
+ trailing incomplete UTF-32 byte sequences (such as a number of bytes not divisible
+ by four) as an error. Those bytes will not be decoded and the number of bytes
+ that have been decoded will be stored in *consumed*.
+
+
+.. cfunction:: PyObject* PyUnicode_EncodeUTF32(const Py_UNICODE *s, Py_ssize_t size, const char *errors, int byteorder)
+
+ Return a Python bytes object holding the UTF-32 encoded value of the Unicode
+ data in *s*. If *byteorder* is not ``0``, output is written according to the
+ following byte order::
+
+ byteorder == -1: little endian
+ byteorder == 0: native byte order (writes a BOM mark)
+ byteorder == 1: big endian
+
+ If byteorder is ``0``, the output string will always start with the Unicode BOM
+ mark (U+FEFF). In the other two modes, no BOM mark is prepended.
+
+ If *Py_UNICODE_WIDE* is not defined, surrogate pairs will be output
+ as a single codepoint.
+
+ Return *NULL* if an exception was raised by the codec.
+
+
+.. cfunction:: PyObject* PyUnicode_AsUTF32String(PyObject *unicode)
+
+ Return a Python string using the UTF-32 encoding in native byte order. The
+ string always starts with a BOM mark. Error handling is "strict". Return
+ *NULL* if an exception was raised by the codec.
+
+
+These are the UTF-16 codec APIs:
+
+.. % --- UTF-16 Codecs ------------------------------------------------------ */
+
+
+.. cfunction:: PyObject* PyUnicode_DecodeUTF16(const char *s, Py_ssize_t size, const char *errors, int *byteorder)
+
+ Decode *length* bytes from a UTF-16 encoded buffer string and return the
+ corresponding Unicode object. *errors* (if non-*NULL*) defines the error
+ handling. It defaults to "strict".
+
+ If *byteorder* is non-*NULL*, the decoder starts decoding using the given byte
+ order::
+
+ *byteorder == -1: little endian
+ *byteorder == 0: native order
+ *byteorder == 1: big endian
+
+ and then switches if the first two bytes of the input data are a byte order mark
+ (BOM) and the specified byte order is native order. This BOM is not copied into
+ the resulting Unicode string. After completion, *\*byteorder* is set to the
+ current byte order at the end of input data.
+
+ If *byteorder* is *NULL*, the codec starts in native order mode.
+
+ Return *NULL* if an exception was raised by the codec.
+
+
+.. cfunction:: PyObject* PyUnicode_DecodeUTF16Stateful(const char *s, Py_ssize_t size, const char *errors, int *byteorder, Py_ssize_t *consumed)
+
+ If *consumed* is *NULL*, behave like :cfunc:`PyUnicode_DecodeUTF16`. If
+ *consumed* is not *NULL*, :cfunc:`PyUnicode_DecodeUTF16Stateful` will not treat
+ trailing incomplete UTF-16 byte sequences (such as an odd number of bytes or a
+ split surrogate pair) as an error. Those bytes will not be decoded and the
+ number of bytes that have been decoded will be stored in *consumed*.
+
+
+.. cfunction:: PyObject* PyUnicode_EncodeUTF16(const Py_UNICODE *s, Py_ssize_t size, const char *errors, int byteorder)
+
+ Return a Python string object holding the UTF-16 encoded value of the Unicode
+ data in *s*. If *byteorder* is not ``0``, output is written according to the
+ following byte order::
+
+ byteorder == -1: little endian
+ byteorder == 0: native byte order (writes a BOM mark)
+ byteorder == 1: big endian
+
+ If byteorder is ``0``, the output string will always start with the Unicode BOM
+ mark (U+FEFF). In the other two modes, no BOM mark is prepended.
+
+ If *Py_UNICODE_WIDE* is defined, a single :ctype:`Py_UNICODE` value may get
+ represented as a surrogate pair. If it is not defined, each :ctype:`Py_UNICODE`
+ values is interpreted as an UCS-2 character.
+
+ Return *NULL* if an exception was raised by the codec.
+
+
+.. cfunction:: PyObject* PyUnicode_AsUTF16String(PyObject *unicode)
+
+ Return a Python string using the UTF-16 encoding in native byte order. The
+ string always starts with a BOM mark. Error handling is "strict". Return
+ *NULL* if an exception was raised by the codec.
+
+These are the "Unicode Escape" codec APIs:
+
+.. % --- Unicode-Escape Codecs ----------------------------------------------
+
+
+.. cfunction:: PyObject* PyUnicode_DecodeUnicodeEscape(const char *s, Py_ssize_t size, const char *errors)
+
+ Create a Unicode object by decoding *size* bytes of the Unicode-Escape encoded
+ string *s*. Return *NULL* if an exception was raised by the codec.
+
+
+.. cfunction:: PyObject* PyUnicode_EncodeUnicodeEscape(const Py_UNICODE *s, Py_ssize_t size)
+
+ Encode the :ctype:`Py_UNICODE` buffer of the given size using Unicode-Escape and
+ return a Python string object. Return *NULL* if an exception was raised by the
+ codec.
+
+
+.. cfunction:: PyObject* PyUnicode_AsUnicodeEscapeString(PyObject *unicode)
+
+ Encode a Unicode object using Unicode-Escape and return the result as Python
+ string object. Error handling is "strict". Return *NULL* if an exception was
+ raised by the codec.
+
+These are the "Raw Unicode Escape" codec APIs:
+
+.. % --- Raw-Unicode-Escape Codecs ------------------------------------------
+
+
+.. cfunction:: PyObject* PyUnicode_DecodeRawUnicodeEscape(const char *s, Py_ssize_t size, const char *errors)
+
+ Create a Unicode object by decoding *size* bytes of the Raw-Unicode-Escape
+ encoded string *s*. Return *NULL* if an exception was raised by the codec.
+
+
+.. cfunction:: PyObject* PyUnicode_EncodeRawUnicodeEscape(const Py_UNICODE *s, Py_ssize_t size, const char *errors)
+
+ Encode the :ctype:`Py_UNICODE` buffer of the given size using Raw-Unicode-Escape
+ and return a Python string object. Return *NULL* if an exception was raised by
+ the codec.
+
+
+.. cfunction:: PyObject* PyUnicode_AsRawUnicodeEscapeString(PyObject *unicode)
+
+ Encode a Unicode object using Raw-Unicode-Escape and return the result as
+ Python string object. Error handling is "strict". Return *NULL* if an exception
+ was raised by the codec.
+
+These are the Latin-1 codec APIs: Latin-1 corresponds to the first 256 Unicode
+ordinals and only these are accepted by the codecs during encoding.
+
+.. % --- Latin-1 Codecs -----------------------------------------------------
+
+
+.. cfunction:: PyObject* PyUnicode_DecodeLatin1(const char *s, Py_ssize_t size, const char *errors)
+
+ Create a Unicode object by decoding *size* bytes of the Latin-1 encoded string
+ *s*. Return *NULL* if an exception was raised by the codec.
+
+
+.. cfunction:: PyObject* PyUnicode_EncodeLatin1(const Py_UNICODE *s, Py_ssize_t size, const char *errors)
+
+ Encode the :ctype:`Py_UNICODE` buffer of the given size using Latin-1 and return
+ a Python string object. Return *NULL* if an exception was raised by the codec.
+
+
+.. cfunction:: PyObject* PyUnicode_AsLatin1String(PyObject *unicode)
+
+ Encode a Unicode object using Latin-1 and return the result as Python string
+ object. Error handling is "strict". Return *NULL* if an exception was raised
+ by the codec.
+
+These are the ASCII codec APIs. Only 7-bit ASCII data is accepted. All other
+codes generate errors.
+
+.. % --- ASCII Codecs -------------------------------------------------------
+
+
+.. cfunction:: PyObject* PyUnicode_DecodeASCII(const char *s, Py_ssize_t size, const char *errors)
+
+ Create a Unicode object by decoding *size* bytes of the ASCII encoded string
+ *s*. Return *NULL* if an exception was raised by the codec.
+
+
+.. cfunction:: PyObject* PyUnicode_EncodeASCII(const Py_UNICODE *s, Py_ssize_t size, const char *errors)
+
+ Encode the :ctype:`Py_UNICODE` buffer of the given size using ASCII and return a
+ Python string object. Return *NULL* if an exception was raised by the codec.
+
+
+.. cfunction:: PyObject* PyUnicode_AsASCIIString(PyObject *unicode)
+
+ Encode a Unicode object using ASCII and return the result as Python string
+ object. Error handling is "strict". Return *NULL* if an exception was raised
+ by the codec.
+
+These are the mapping codec APIs:
+
+.. % --- Character Map Codecs -----------------------------------------------
+
+This codec is special in that it can be used to implement many different codecs
+(and this is in fact what was done to obtain most of the standard codecs
+included in the :mod:`encodings` package). The codec uses mapping to encode and
+decode characters.
+
+Decoding mappings must map single string characters to single Unicode
+characters, integers (which are then interpreted as Unicode ordinals) or None
+(meaning "undefined mapping" and causing an error).
+
+Encoding mappings must map single Unicode characters to single string
+characters, integers (which are then interpreted as Latin-1 ordinals) or None
+(meaning "undefined mapping" and causing an error).
+
+The mapping objects provided must only support the __getitem__ mapping
+interface.
+
+If a character lookup fails with a LookupError, the character is copied as-is
+meaning that its ordinal value will be interpreted as Unicode or Latin-1 ordinal
+resp. Because of this, mappings only need to contain those mappings which map
+characters to different code points.
+
+
+.. cfunction:: PyObject* PyUnicode_DecodeCharmap(const char *s, Py_ssize_t size, PyObject *mapping, const char *errors)
+
+ Create a Unicode object by decoding *size* bytes of the encoded string *s* using
+ the given *mapping* object. Return *NULL* if an exception was raised by the
+ codec. If *mapping* is *NULL* latin-1 decoding will be done. Else it can be a
+ dictionary mapping byte or a unicode string, which is treated as a lookup table.
+ Byte values greater that the length of the string and U+FFFE "characters" are
+ treated as "undefined mapping".
+
+
+.. cfunction:: PyObject* PyUnicode_EncodeCharmap(const Py_UNICODE *s, Py_ssize_t size, PyObject *mapping, const char *errors)
+
+ Encode the :ctype:`Py_UNICODE` buffer of the given size using the given
+ *mapping* object and return a Python string object. Return *NULL* if an
+ exception was raised by the codec.
+
+
+.. cfunction:: PyObject* PyUnicode_AsCharmapString(PyObject *unicode, PyObject *mapping)
+
+ Encode a Unicode object using the given *mapping* object and return the result
+ as Python string object. Error handling is "strict". Return *NULL* if an
+ exception was raised by the codec.
+
+The following codec API is special in that maps Unicode to Unicode.
+
+
+.. cfunction:: PyObject* PyUnicode_TranslateCharmap(const Py_UNICODE *s, Py_ssize_t size, PyObject *table, const char *errors)
+
+ Translate a :ctype:`Py_UNICODE` buffer of the given length by applying a
+ character mapping *table* to it and return the resulting Unicode object. Return
+ *NULL* when an exception was raised by the codec.
+
+ The *mapping* table must map Unicode ordinal integers to Unicode ordinal
+ integers or None (causing deletion of the character).
+
+ Mapping tables need only provide the :meth:`__getitem__` interface; dictionaries
+ and sequences work well. Unmapped character ordinals (ones which cause a
+ :exc:`LookupError`) are left untouched and are copied as-is.
+
+These are the MBCS codec APIs. They are currently only available on Windows and
+use the Win32 MBCS converters to implement the conversions. Note that MBCS (or
+DBCS) is a class of encodings, not just one. The target encoding is defined by
+the user settings on the machine running the codec.
+
+.. % --- MBCS codecs for Windows --------------------------------------------
+
+
+.. cfunction:: PyObject* PyUnicode_DecodeMBCS(const char *s, Py_ssize_t size, const char *errors)
+
+ Create a Unicode object by decoding *size* bytes of the MBCS encoded string *s*.
+ Return *NULL* if an exception was raised by the codec.
+
+
+.. cfunction:: PyObject* PyUnicode_DecodeMBCSStateful(const char *s, int size, const char *errors, int *consumed)
+
+ If *consumed* is *NULL*, behave like :cfunc:`PyUnicode_DecodeMBCS`. If
+ *consumed* is not *NULL*, :cfunc:`PyUnicode_DecodeMBCSStateful` will not decode
+ trailing lead byte and the number of bytes that have been decoded will be stored
+ in *consumed*.
+
+
+.. cfunction:: PyObject* PyUnicode_EncodeMBCS(const Py_UNICODE *s, Py_ssize_t size, const char *errors)
+
+ Encode the :ctype:`Py_UNICODE` buffer of the given size using MBCS and return a
+ Python string object. Return *NULL* if an exception was raised by the codec.
+
+
+.. cfunction:: PyObject* PyUnicode_AsMBCSString(PyObject *unicode)
+
+ Encode a Unicode object using MBCS and return the result as Python string
+ object. Error handling is "strict". Return *NULL* if an exception was raised
+ by the codec.
+
+.. % --- Methods & Slots ----------------------------------------------------
+
+
+.. _unicodemethodsandslots:
+
+Methods and Slot Functions
+^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The following APIs are capable of handling Unicode objects and strings on input
+(we refer to them as strings in the descriptions) and return Unicode objects or
+integers as appropriate.
+
+They all return *NULL* or ``-1`` if an exception occurs.
+
+
+.. cfunction:: PyObject* PyUnicode_Concat(PyObject *left, PyObject *right)
+
+ Concat two strings giving a new Unicode string.
+
+
+.. cfunction:: PyObject* PyUnicode_Split(PyObject *s, PyObject *sep, Py_ssize_t maxsplit)
+
+ Split a string giving a list of Unicode strings. If sep is *NULL*, splitting
+ will be done at all whitespace substrings. Otherwise, splits occur at the given
+ separator. At most *maxsplit* splits will be done. If negative, no limit is
+ set. Separators are not included in the resulting list.
+
+
+.. cfunction:: PyObject* PyUnicode_Splitlines(PyObject *s, int keepend)
+
+ Split a Unicode string at line breaks, returning a list of Unicode strings.
+ CRLF is considered to be one line break. If *keepend* is 0, the Line break
+ characters are not included in the resulting strings.
+
+
+.. cfunction:: PyObject* PyUnicode_Translate(PyObject *str, PyObject *table, const char *errors)
+
+ Translate a string by applying a character mapping table to it and return the
+ resulting Unicode object.
+
+ The mapping table must map Unicode ordinal integers to Unicode ordinal integers
+ or None (causing deletion of the character).
+
+ Mapping tables need only provide the :meth:`__getitem__` interface; dictionaries
+ and sequences work well. Unmapped character ordinals (ones which cause a
+ :exc:`LookupError`) are left untouched and are copied as-is.
+
+ *errors* has the usual meaning for codecs. It may be *NULL* which indicates to
+ use the default error handling.
+
+
+.. cfunction:: PyObject* PyUnicode_Join(PyObject *separator, PyObject *seq)
+
+ Join a sequence of strings using the given separator and return the resulting
+ Unicode string.
+
+
+.. cfunction:: int PyUnicode_Tailmatch(PyObject *str, PyObject *substr, Py_ssize_t start, Py_ssize_t end, int direction)
+
+ Return 1 if *substr* matches *str*[*start*:*end*] at the given tail end
+ (*direction* == -1 means to do a prefix match, *direction* == 1 a suffix match),
+ 0 otherwise. Return ``-1`` if an error occurred.
+
+
+.. cfunction:: Py_ssize_t PyUnicode_Find(PyObject *str, PyObject *substr, Py_ssize_t start, Py_ssize_t end, int direction)
+
+ Return the first position of *substr* in *str*[*start*:*end*] using the given
+ *direction* (*direction* == 1 means to do a forward search, *direction* == -1 a
+ backward search). The return value is the index of the first match; a value of
+ ``-1`` indicates that no match was found, and ``-2`` indicates that an error
+ occurred and an exception has been set.
+
+
+.. cfunction:: Py_ssize_t PyUnicode_Count(PyObject *str, PyObject *substr, Py_ssize_t start, Py_ssize_t end)
+
+ Return the number of non-overlapping occurrences of *substr* in
+ ``str[start:end]``. Return ``-1`` if an error occurred.
+
+
+.. cfunction:: PyObject* PyUnicode_Replace(PyObject *str, PyObject *substr, PyObject *replstr, Py_ssize_t maxcount)
+
+ Replace at most *maxcount* occurrences of *substr* in *str* with *replstr* and
+ return the resulting Unicode object. *maxcount* == -1 means replace all
+ occurrences.
+
+
+.. cfunction:: int PyUnicode_Compare(PyObject *left, PyObject *right)
+
+ Compare two strings and return -1, 0, 1 for less than, equal, and greater than,
+ respectively.
+
+
+.. cfunction:: int PyUnicode_RichCompare(PyObject *left, PyObject *right, int op)
+
+ Rich compare two unicode strings and return one of the following:
+
+ * ``NULL`` in case an exception was raised
+ * :const:`Py_True` or :const:`Py_False` for successful comparisons
+ * :const:`Py_NotImplemented` in case the type combination is unknown
+
+ Note that :const:`Py_EQ` and :const:`Py_NE` comparisons can cause a
+ :exc:`UnicodeWarning` in case the conversion of the arguments to Unicode fails
+ with a :exc:`UnicodeDecodeError`.
+
+ Possible values for *op* are :const:`Py_GT`, :const:`Py_GE`, :const:`Py_EQ`,
+ :const:`Py_NE`, :const:`Py_LT`, and :const:`Py_LE`.
+
+
+.. cfunction:: PyObject* PyUnicode_Format(PyObject *format, PyObject *args)
+
+ Return a new string object from *format* and *args*; this is analogous to
+ ``format % args``. The *args* argument must be a tuple.
+
+
+.. cfunction:: int PyUnicode_Contains(PyObject *container, PyObject *element)
+
+ Check whether *element* is contained in *container* and return true or false
+ accordingly.
+
+ *element* has to coerce to a one element Unicode string. ``-1`` is returned if
+ there was an error.
+
+
+.. cfunction:: void PyUnicode_InternInPlace(PyObject **string)
+
+ Intern the argument *\*string* in place. The argument must be the address of a
+ pointer variable pointing to a Python unicode 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.)
+
+
+.. cfunction:: PyObject* PyUnicode_InternFromString(const char *v)
+
+ A combination of :cfunc:`PyUnicode_FromString` and
+ :cfunc:`PyUnicode_InternInPlace`, returning either a new unicode string object
+ that has been interned, or a new ("owned") reference to an earlier interned
+ string object with the same value.
+