Unicode物件與編碼
*****************


Unicode对象
===========

自从python3.3中实现了 **PEP 393** 以来，Unicode对象在内部使用各种表示
形式，以便在保持内存效率的同时处理完整范围的Unicode字符。对于所有代码
点都低于128、256或65536的字符串，有一些特殊情况；否则，代码点必须低于
1114112（这是完整的Unicode范围）。

"Py_UNICODE*" and UTF-8 representations are created on demand and
cached in the Unicode object.  The "Py_UNICODE*" representation is
deprecated and inefficient.

Due to the transition between the old APIs and the new APIs, Unicode
objects can internally be in two states depending on how they were
created:

* "canonical" Unicode objects are all objects created by a non-
  deprecated Unicode API.  They use the most efficient representation
  allowed by the implementation.

* "legacy" Unicode objects have been created through one of the
  deprecated APIs (typically "PyUnicode_FromUnicode()") and only bear
  the "Py_UNICODE*" representation; you will have to call
  "PyUnicode_READY()" on them before calling any other API.

備註:

  The "legacy" Unicode object will be removed in Python 3.12 with
  deprecated APIs. All Unicode objects will be "canonical" since then.
  See **PEP 623** for more information.


Unicode类型
-----------

以下是用于Python中Unicode实现的基本Unicode对象类型：

type Py_UCS4
type Py_UCS2
type Py_UCS1
    * Part of the Stable ABI.*

   这些类型是无符号整数类型的类型定义，其宽度足以分别包含 32 位、16 位
   和 8 位字符。 当需要处理单个 Unicode 字符时，请使用 "Py_UCS4"。

   3.3 版新加入.

type Py_UNICODE

   This is a typedef of "wchar_t", which is a 16-bit type or 32-bit
   type depending on the platform.

   3.3 版更變: 在以前的版本中，这是16位类型还是32位类型，这取决于您在
   构建时选择的是“窄”还是“宽”Unicode版本的Python。

type PyASCIIObject
type PyCompactUnicodeObject
type PyUnicodeObject

   这些关于 "PyObject" 的子类型表示了一个 Python Unicode 对象。 在几乎
   所有情形下，它们不应该被直接使用，因为所有处理 Unicode 对象的 API
   函数都接受并返回 "PyObject" 类型的指针。

   3.3 版新加入.

PyTypeObject PyUnicode_Type
    * Part of the Stable ABI.*

   这个 "PyTypeObject" 实例代表 Python Unicode 类型。 它作为 "str" 公
   开给 Python 代码。

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:

int PyUnicode_Check(PyObject *o)

   如果对象*o*是Unicode对象或Unicode子类型的实例，则返回“真"。此函数始
   终成功。

int PyUnicode_CheckExact(PyObject *o)

   如果对象*o*是Unicode对象，但不是子类型的实例，则返回“真”。此函数始
   终成功。

int PyUnicode_READY(PyObject *o)

   Ensure the string object *o* is in the "canonical" representation.
   This is required before using any of the access macros described
   below.

   Returns "0" on success and "-1" with an exception set on failure,
   which in particular happens if memory allocation fails.

   3.3 版新加入.

   自從版本 3.10 後不推薦使用，將會自版本 3.12 中移除。: This API will
   be removed with "PyUnicode_FromUnicode()".

Py_ssize_t PyUnicode_GET_LENGTH(PyObject *o)

   返回Unicode字符串的长度（以代码点为单位）*o*必须是“规范”表达方式中
   的Unicode对象（未选中）。

   3.3 版新加入.

Py_UCS1 *PyUnicode_1BYTE_DATA(PyObject *o)
Py_UCS2 *PyUnicode_2BYTE_DATA(PyObject *o)
Py_UCS4 *PyUnicode_4BYTE_DATA(PyObject *o)

   Return a pointer to the canonical representation cast to UCS1, UCS2
   or UCS4 integer types for direct character access.  No checks are
   performed if the canonical representation has the correct character
   size; use "PyUnicode_KIND()" to select the right macro.  Make sure
   "PyUnicode_READY()" has been called before accessing this.

   3.3 版新加入.

PyUnicode_WCHAR_KIND
PyUnicode_1BYTE_KIND
PyUnicode_2BYTE_KIND
PyUnicode_4BYTE_KIND

   返回 "PyUnicode_KIND()" 宏的值。

   3.3 版新加入.

   自從版本 3.10 後不推薦使用，將會自版本 3.12 中移除。:
   "PyUnicode_WCHAR_KIND" 已棄用。

unsigned int PyUnicode_KIND(PyObject *o)

   返回一个PyUnicode类常量（见上文），指示此Unicode对象用于存储其数据
   的每个字符的字节数*o*必须是“规范”表达方式中的Unicode对象（未选中）
   。

   3.3 版新加入.

void *PyUnicode_DATA(PyObject *o)

   返回指向原始Unicode缓冲区的空指针*o*必须是“规范”表达方式中的Unicode
   对象（未选中）。

   3.3 版新加入.

void PyUnicode_WRITE(int kind, void *data, Py_ssize_t index, Py_UCS4 value)

   Write into a canonical representation *data* (as obtained with
   "PyUnicode_DATA()").  This macro does not do any sanity checks and
   is intended for usage in loops.  The caller should cache the *kind*
   value and *data* pointer as obtained from other macro calls.
   *index* is the index in the string (starts at 0) and *value* is the
   new code point value which should be written to that location.

   3.3 版新加入.

Py_UCS4 PyUnicode_READ(int kind, void *data, Py_ssize_t index)

   Read a code point from a canonical representation *data* (as
   obtained with "PyUnicode_DATA()").  No checks or ready calls are
   performed.

   3.3 版新加入.

Py_UCS4 PyUnicode_READ_CHAR(PyObject *o, Py_ssize_t index)

   Read a character from a Unicode object *o*, which must be in the
   "canonical" representation.  This is less efficient than
   "PyUnicode_READ()" if you do multiple consecutive reads.

   3.3 版新加入.

PyUnicode_MAX_CHAR_VALUE(o)

   返回适合于基于*o*创建另一个字符串的最大代码点，该字符串必须在“规范”
   表达方式中。这始终是一种近似，但比在字符串上迭代更有效。

   3.3 版新加入.

Py_ssize_t PyUnicode_GET_SIZE(PyObject *o)

   Return the size of the deprecated "Py_UNICODE" representation, in
   code units (this includes surrogate pairs as 2 units).  *o* has to
   be a Unicode object (not checked).

   自從版本 3.3 後不推薦使用，將會自版本 3.12 中移除。: 旧式 Unicode
   API 的一部分，请迁移到使用 "PyUnicode_GET_LENGTH()"。

Py_ssize_t PyUnicode_GET_DATA_SIZE(PyObject *o)

   Return the size of the deprecated "Py_UNICODE" representation in
   bytes.  *o* has to be a Unicode object (not checked).

   自從版本 3.3 後不推薦使用，將會自版本 3.12 中移除。: 旧式 Unicode
   API 的一部分，请迁移到使用 "PyUnicode_GET_LENGTH()"。

Py_UNICODE *PyUnicode_AS_UNICODE(PyObject *o)
const char *PyUnicode_AS_DATA(PyObject *o)

   Return a pointer to a "Py_UNICODE" representation of the object.
   The returned buffer is always terminated with an extra null code
   point.  It may also contain embedded null code points, which would
   cause the string to be truncated when used in most C functions.
   The "AS_DATA" form casts the pointer to "const char*".  The *o*
   argument has to be a Unicode object (not checked).

   3.3 版更變: This macro is now inefficient -- because in many cases
   the "Py_UNICODE" representation does not exist and needs to be
   created -- and can fail (return "NULL" with an exception set).  Try
   to port the code to use the new "PyUnicode_nBYTE_DATA()" macros or
   use "PyUnicode_WRITE()" or "PyUnicode_READ()".

   自從版本 3.3 後不推薦使用，將會自版本 3.12 中移除。: 旧式 Unicode
   API 的一部分，请迁移到使用 "PyUnicode_nBYTE_DATA()" 宏族。

int PyUnicode_IsIdentifier(PyObject *o)
    * Part of the Stable ABI.*

   如果字符串按照语言定义是合法的标识符则返回 "1"，参见 标识符和关键字
   小节。 否则返回 "0"。

   3.9 版更變: The function does not call "Py_FatalError()" anymore if
   the string is not ready.


Unicode字符属性
---------------

Unicode提供了许多不同的字符特性。最常需要的宏可以通过这些宏获得，这些
宏根据Python配置映射到C函数。

int Py_UNICODE_ISSPACE(Py_UCS4 ch)

   根据 *ch* 是否为空白字符返回 "1" 或 "0"。

int Py_UNICODE_ISLOWER(Py_UCS4 ch)

   根据 *ch* 是否为小写字符返回 "1" 或 "0"。

int Py_UNICODE_ISUPPER(Py_UCS4 ch)

   根据 *ch* 是否为大写字符返回 "1" 或 "0"

int Py_UNICODE_ISTITLE(Py_UCS4 ch)

   根据 *ch* 是否为标题化的大小写返回 "1" 或 "0"。

int Py_UNICODE_ISLINEBREAK(Py_UCS4 ch)

   根据 *ch* 是否为换行类字符返回 "1" 或 "0"。

int Py_UNICODE_ISDECIMAL(Py_UCS4 ch)

   根据 *ch* 是否为十进制数字符返回 "1" 或 "0"。

int Py_UNICODE_ISDIGIT(Py_UCS4 ch)

   根据 *ch* 是否为数码类字符返回 "1" 或 "0"。

int Py_UNICODE_ISNUMERIC(Py_UCS4 ch)

   根据 *ch* 是否为数值类字符返回 "1" 或 "0"。

int Py_UNICODE_ISALPHA(Py_UCS4 ch)

   根据 *ch* 是否为字母类字符返回 "1" 或 "0"。

int Py_UNICODE_ISALNUM(Py_UCS4 ch)

   根据 *ch* 是否为字母数字类字符返回 "1" 或 "0"。

int Py_UNICODE_ISPRINTABLE(Py_UCS4 ch)

   Return "1" or "0" depending on whether *ch* is a printable
   character. Nonprintable characters are those characters defined in
   the Unicode character database as "Other" or "Separator", excepting
   the ASCII space (0x20) which is considered printable.  (Note that
   printable characters in this context are those which should not be
   escaped when "repr()" is invoked on a string. It has no bearing on
   the handling of strings written to "sys.stdout" or "sys.stderr".)

These APIs can be used for fast direct character conversions:

Py_UCS4 Py_UNICODE_TOLOWER(Py_UCS4 ch)

   Return the character *ch* converted to lower case.

   3.3 版後已棄用: This function uses simple case mappings.

Py_UCS4 Py_UNICODE_TOUPPER(Py_UCS4 ch)

   Return the character *ch* converted to upper case.

   3.3 版後已棄用: This function uses simple case mappings.

Py_UCS4 Py_UNICODE_TOTITLE(Py_UCS4 ch)

   Return the character *ch* converted to title case.

   3.3 版後已棄用: This function uses simple case mappings.

int Py_UNICODE_TODECIMAL(Py_UCS4 ch)

   Return the character *ch* converted to a decimal positive integer.
   Return "-1" if this is not possible.  This macro does not raise
   exceptions.

int Py_UNICODE_TODIGIT(Py_UCS4 ch)

   Return the character *ch* converted to a single digit integer.
   Return "-1" if this is not possible.  This macro does not raise
   exceptions.

double Py_UNICODE_TONUMERIC(Py_UCS4 ch)

   Return the character *ch* converted to a double. Return "-1.0" if
   this is not possible.  This macro does not raise exceptions.

These APIs can be used to work with surrogates:

Py_UNICODE_IS_SURROGATE(ch)

   Check if *ch* is a surrogate ("0xD800 <= ch <= 0xDFFF").

Py_UNICODE_IS_HIGH_SURROGATE(ch)

   Check if *ch* is a high surrogate ("0xD800 <= ch <= 0xDBFF").

Py_UNICODE_IS_LOW_SURROGATE(ch)

   Check if *ch* is a low surrogate ("0xDC00 <= ch <= 0xDFFF").

Py_UNICODE_JOIN_SURROGATES(high, low)

   Join two surrogate characters and return a single Py_UCS4 value.
   *high* and *low* are respectively the leading and trailing
   surrogates in a surrogate pair.


Creating and accessing Unicode strings
--------------------------------------

To create Unicode objects and access their basic sequence properties,
use these APIs:

PyObject *PyUnicode_New(Py_ssize_t size, Py_UCS4 maxchar)
    *返回值：新的引用。*

   Create a new Unicode object.  *maxchar* should be the true maximum
   code point to be placed in the string.  As an approximation, it can
   be rounded up to the nearest value in the sequence 127, 255, 65535,
   1114111.

   This is the recommended way to allocate a new Unicode object.
   Objects created using this function are not resizable.

   3.3 版新加入.

PyObject *PyUnicode_FromKindAndData(int kind, const void *buffer, Py_ssize_t size)
    *返回值：新的引用。*

   Create a new Unicode object with the given *kind* (possible values
   are "PyUnicode_1BYTE_KIND" etc., as returned by
   "PyUnicode_KIND()").  The *buffer* must point to an array of *size*
   units of 1, 2 or 4 bytes per character, as given by the kind.

   3.3 版新加入.

PyObject *PyUnicode_FromStringAndSize(const char *u, Py_ssize_t size)
    *返回值：新的引用。** Part of the Stable ABI.*

   Create a Unicode object from the char buffer *u*.  The bytes will
   be interpreted as being UTF-8 encoded.  The buffer is copied into
   the new object. If the buffer is not "NULL", the return value might
   be a shared object, i.e. modification of the data is not allowed.

   If *u* is "NULL", this function behaves like
   "PyUnicode_FromUnicode()" with the buffer set to "NULL".  This
   usage is deprecated in favor of "PyUnicode_New()", and will be
   removed in Python 3.12.

PyObject *PyUnicode_FromString(const char *u)
    *返回值：新的引用。** Part of the Stable ABI.*

   Create a Unicode object from a UTF-8 encoded null-terminated char
   buffer *u*.

PyObject *PyUnicode_FromFormat(const char *format, ...)
    *返回值：新的引用。** Part of the Stable ABI.*

   Take a C "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* ASCII-encoded string. The
   following format characters are allowed:

   +---------------------+-----------------------+------------------------------------+
   | 格式字符            | 类型                  | 注释                               |
   |=====================|=======================|====================================|
   | "%%"                | *n/a*                 | 文字%字符。                        |
   +---------------------+-----------------------+------------------------------------+
   | "%c"                | int                   | 单个字符，表示为C 语言的整型。     |
   +---------------------+-----------------------+------------------------------------+
   | "%d"                | int                   | 等價於 "printf("%d")". [1]         |
   +---------------------+-----------------------+------------------------------------+
   | "%u"                | unsigned int          | 等價於 "printf("%u")". [1]         |
   +---------------------+-----------------------+------------------------------------+
   | "%ld"               | long                  | 等價於 "printf("%ld")". [1]        |
   +---------------------+-----------------------+------------------------------------+
   | "%li"               | long                  | 等價於 "printf("%li")". [1]        |
   +---------------------+-----------------------+------------------------------------+
   | "%lu"               | unsigned long         | 等價於 "printf("%lu")". [1]        |
   +---------------------+-----------------------+------------------------------------+
   | "%lld"              | long long             | 等價於 "printf("%lld")". [1]       |
   +---------------------+-----------------------+------------------------------------+
   | "%lli"              | long long             | 等價於 "printf("%lli")". [1]       |
   +---------------------+-----------------------+------------------------------------+
   | "%llu"              | unsigned long long    | 等價於 "printf("%llu")". [1]       |
   +---------------------+-----------------------+------------------------------------+
   | "%zd"               | "Py_ssize_t"          | 等價於 "printf("%zd")". [1]        |
   +---------------------+-----------------------+------------------------------------+
   | "%zi"               | "Py_ssize_t"          | 等價於 "printf("%zi")". [1]        |
   +---------------------+-----------------------+------------------------------------+
   | "%zu"               | size_t                | 等價於 "printf("%zu")". [1]        |
   +---------------------+-----------------------+------------------------------------+
   | "%i"                | int                   | 等價於 "printf("%i")". [1]         |
   +---------------------+-----------------------+------------------------------------+
   | "%x"                | int                   | 等價於 "printf("%x")". [1]         |
   +---------------------+-----------------------+------------------------------------+
   | "%s"                | const char*           | 以 null 为终止符的 C 字符数组。    |
   +---------------------+-----------------------+------------------------------------+
   | "%p"                | const void*           | 一个 C 指针的十六进制表示形式。 基 |
   |                     |                       | 本等价于 "printf("%p")" 但它会确   |
   |                     |                       | 保以字面值 "0x" 开头，不论系统平台 |
   |                     |                       | 上 "printf" 的输出是什么。         |
   +---------------------+-----------------------+------------------------------------+
   | "%A"                | PyObject*             | "ascii()" 调用的结果。             |
   +---------------------+-----------------------+------------------------------------+
   | "%U"                | PyObject*             | 一 Unicode 物件。                  |
   +---------------------+-----------------------+------------------------------------+
   | "%V"                | PyObject*, const      | A Unicode object (which may be     |
   |                     | char*                 | "NULL") and a null-terminated C    |
   |                     |                       | character array as a second        |
   |                     |                       | parameter (which will be used, if  |
   |                     |                       | the first parameter is "NULL").    |
   +---------------------+-----------------------+------------------------------------+
   | "%S"                | PyObject*             | The result of calling              |
   |                     |                       | "PyObject_Str()".                  |
   +---------------------+-----------------------+------------------------------------+
   | "%R"                | PyObject*             | The result of calling              |
   |                     |                       | "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.

   備註:

     The width formatter unit is number of characters rather than
     bytes. The precision formatter unit is number of bytes for ""%s""
     and ""%V"" (if the "PyObject*" argument is "NULL"), and a number
     of characters for ""%A"", ""%U"", ""%S"", ""%R"" and ""%V"" (if
     the "PyObject*" argument is not "NULL").

   [1] For integer specifiers (d, u, ld, li, lu, lld, lli, llu, zd,
       zi, zu, i, x): the 0-conversion flag has effect even when a
       precision is given.

   3.2 版更變: Support for ""%lld"" and ""%llu"" added.

   3.3 版更變: Support for ""%li"", ""%lli"" and ""%zi"" added.

   3.4 版更變: Support width and precision formatter for ""%s"",
   ""%A"", ""%U"", ""%V"", ""%S"", ""%R"" added.

PyObject *PyUnicode_FromFormatV(const char *format, va_list vargs)
    *返回值：新的引用。** Part of the Stable ABI.*

   Identical to "PyUnicode_FromFormat()" except that it takes exactly
   two arguments.

PyObject *PyUnicode_FromEncodedObject(PyObject *obj, const char *encoding, const char *errors)
    *返回值：新的引用。** Part of the Stable ABI.*

   Decode an encoded object *obj* to a Unicode object.

   "bytes", "bytearray" and other *bytes-like 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 Built-in Codecs for details).

   All other objects, including Unicode objects, cause a "TypeError"
   to be set.

   The API returns "NULL" if there was an error.  The caller is
   responsible for decref'ing the returned objects.

Py_ssize_t PyUnicode_GetLength(PyObject *unicode)
    * Part of the Stable ABI since version 3.7.*

   Return the length of the Unicode object, in code points.

   3.3 版新加入.

Py_ssize_t PyUnicode_CopyCharacters(PyObject *to, Py_ssize_t to_start, PyObject *from, Py_ssize_t from_start, Py_ssize_t how_many)

   Copy characters from one Unicode object into another.  This
   function performs character conversion when necessary and falls
   back to "memcpy()" if possible.  Returns "-1" and sets an exception
   on error, otherwise returns the number of copied characters.

   3.3 版新加入.

Py_ssize_t PyUnicode_Fill(PyObject *unicode, Py_ssize_t start, Py_ssize_t length, Py_UCS4 fill_char)

   Fill a string with a character: write *fill_char* into
   "unicode[start:start+length]".

   Fail if *fill_char* is bigger than the string maximum character, or
   if the string has more than 1 reference.

   Return the number of written character, or return "-1" and raise an
   exception on error.

   3.3 版新加入.

int PyUnicode_WriteChar(PyObject *unicode, Py_ssize_t index, Py_UCS4 character)
    * Part of the Stable ABI since version 3.7.*

   Write a character to a string.  The string must have been created
   through "PyUnicode_New()".  Since Unicode strings are supposed to
   be immutable, the string must not be shared, or have been hashed
   yet.

   This function checks that *unicode* is a Unicode object, that the
   index is not out of bounds, and that the object can be modified
   safely (i.e. that it its reference count is one).

   3.3 版新加入.

Py_UCS4 PyUnicode_ReadChar(PyObject *unicode, Py_ssize_t index)
    * Part of the Stable ABI since version 3.7.*

   Read a character from a string.  This function checks that
   *unicode* is a Unicode object and the index is not out of bounds,
   in contrast to the macro version "PyUnicode_READ_CHAR()".

   3.3 版新加入.

PyObject *PyUnicode_Substring(PyObject *str, Py_ssize_t start, Py_ssize_t end)
    *返回值：新的引用。** Part of the Stable ABI since version 3.7.*

   Return a substring of *str*, from character index *start*
   (included) to character index *end* (excluded).  Negative indices
   are not supported.

   3.3 版新加入.

Py_UCS4 *PyUnicode_AsUCS4(PyObject *u, Py_UCS4 *buffer, Py_ssize_t buflen, int copy_null)
    * Part of the Stable ABI since version 3.7.*

   Copy the string *u* into a UCS4 buffer, including a null character,
   if *copy_null* is set.  Returns "NULL" and sets an exception on
   error (in particular, a "SystemError" if *buflen* is smaller than
   the length of *u*).  *buffer* is returned on success.

   3.3 版新加入.

Py_UCS4 *PyUnicode_AsUCS4Copy(PyObject *u)
    * Part of the Stable ABI since version 3.7.*

   Copy the string *u* into a new UCS4 buffer that is allocated using
   "PyMem_Malloc()".  If this fails, "NULL" is returned with a
   "MemoryError" set.  The returned buffer always has an extra null
   code point appended.

   3.3 版新加入.


Deprecated Py_UNICODE APIs
--------------------------

自從版本 3.3 後不推薦使用，將會自版本 3.12 中移除。.

These API functions are deprecated with the implementation of **PEP
393**. Extension modules can continue using them, as they will not be
removed in Python 3.x, but need to be aware that their use can now
cause performance and memory hits.

PyObject *PyUnicode_FromUnicode(const Py_UNICODE *u, Py_ssize_t size)
    *返回值：新的引用。*

   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".

   If the buffer is "NULL", "PyUnicode_READY()" must be called once
   the string content has been filled before using any of the access
   macros such as "PyUnicode_KIND()".

   自從版本 3.3 後不推薦使用，將會自版本 3.12 中移除。: Part of the
   old-style Unicode API, please migrate to using
   "PyUnicode_FromKindAndData()", "PyUnicode_FromWideChar()", or
   "PyUnicode_New()".

Py_UNICODE *PyUnicode_AsUnicode(PyObject *unicode)

   Return a read-only pointer to the Unicode object's internal
   "Py_UNICODE" buffer, or "NULL" on error. This will create the
   "Py_UNICODE*" representation of the object if it is not yet
   available. The buffer is always terminated with an extra null code
   point. Note that the resulting "Py_UNICODE" string may also contain
   embedded null code points, which would cause the string to be
   truncated when used in most C functions.

   自從版本 3.3 後不推薦使用，將會自版本 3.12 中移除。: Part of the
   old-style Unicode API, please migrate to using
   "PyUnicode_AsUCS4()", "PyUnicode_AsWideChar()",
   "PyUnicode_ReadChar()" or similar new APIs.

PyObject *PyUnicode_TransformDecimalToASCII(Py_UNICODE *s, Py_ssize_t size)
    *返回值：新的引用。*

   Create a Unicode object by replacing all decimal digits in
   "Py_UNICODE" buffer of the given *size* by ASCII digits 0--9
   according to their decimal value.  Return "NULL" if an exception
   occurs.

   自從版本 3.3 後不推薦使用，將會自版本 3.11 中移除。: Part of the
   old-style "Py_UNICODE" API; please migrate to using
   "Py_UNICODE_TODECIMAL()".

Py_UNICODE *PyUnicode_AsUnicodeAndSize(PyObject *unicode, Py_ssize_t *size)

   Like "PyUnicode_AsUnicode()", but also saves the "Py_UNICODE()"
   array length (excluding the extra null terminator) in *size*. Note
   that the resulting "Py_UNICODE*" string may contain embedded null
   code points, which would cause the string to be truncated when used
   in most C functions.

   3.3 版新加入.

   自從版本 3.3 後不推薦使用，將會自版本 3.12 中移除。: Part of the
   old-style Unicode API, please migrate to using
   "PyUnicode_AsUCS4()", "PyUnicode_AsWideChar()",
   "PyUnicode_ReadChar()" or similar new APIs.

Py_ssize_t PyUnicode_GetSize(PyObject *unicode)
    * Part of the Stable ABI.*

   Return the size of the deprecated "Py_UNICODE" representation, in
   code units (this includes surrogate pairs as 2 units).

   自從版本 3.3 後不推薦使用，將會自版本 3.12 中移除。: 旧式 Unicode
   API 的一部分，请迁移到使用 "PyUnicode_GET_LENGTH()"。

PyObject *PyUnicode_FromObject(PyObject *obj)
    *返回值：新的引用。** Part of the Stable ABI.*

   Copy an instance of a Unicode subtype to a new true Unicode object
   if necessary. If *obj* is already a true Unicode object (not a
   subtype), return the reference with incremented refcount.

   Objects other than Unicode or its subtypes will cause a
   "TypeError".


Locale Encoding
---------------

The current locale encoding can be used to decode text from the
operating system.

PyObject *PyUnicode_DecodeLocaleAndSize(const char *str, Py_ssize_t len, const char *errors)
    *返回值：新的引用。** Part of the Stable ABI since version 3.7.*

   Decode a string from UTF-8 on Android and VxWorks, or from the
   current locale encoding on other platforms. The supported error
   handlers are ""strict"" and ""surrogateescape"" (**PEP 383**). The
   decoder uses ""strict"" error handler if *errors* is "NULL".  *str*
   must end with a null character but cannot contain embedded null
   characters.

   Use "PyUnicode_DecodeFSDefaultAndSize()" to decode a string from
   "Py_FileSystemDefaultEncoding" (the locale encoding read at Python
   startup).

   This function ignores the Python UTF-8 Mode.

   也參考: "Py_DecodeLocale()" 函式。

   3.3 版新加入.

   3.7 版更變: The function now also uses the current locale encoding
   for the "surrogateescape" error handler, except on Android.
   Previously, "Py_DecodeLocale()" was used for the "surrogateescape",
   and the current locale encoding was used for "strict".

PyObject *PyUnicode_DecodeLocale(const char *str, const char *errors)
    *返回值：新的引用。** Part of the Stable ABI since version 3.7.*

   Similar to "PyUnicode_DecodeLocaleAndSize()", but compute the
   string length using "strlen()".

   3.3 版新加入.

PyObject *PyUnicode_EncodeLocale(PyObject *unicode, const char *errors)
    *返回值：新的引用。** Part of the Stable ABI since version 3.7.*

   Encode a Unicode object to UTF-8 on Android and VxWorks, or to the
   current locale encoding on other platforms. The supported error
   handlers are ""strict"" and ""surrogateescape"" (**PEP 383**). The
   encoder uses ""strict"" error handler if *errors* is "NULL". Return
   a "bytes" object. *unicode* cannot contain embedded null
   characters.

   Use "PyUnicode_EncodeFSDefault()" to encode a string to
   "Py_FileSystemDefaultEncoding" (the locale encoding read at Python
   startup).

   This function ignores the Python UTF-8 Mode.

   也參考: "Py_EncodeLocale()" 函式。

   3.3 版新加入.

   3.7 版更變: The function now also uses the current locale encoding
   for the "surrogateescape" error handler, except on Android.
   Previously, "Py_EncodeLocale()" was used for the "surrogateescape",
   and the current locale encoding was used for "strict".


文件系统编码格式
----------------

To encode and decode file names and other environment strings,
"Py_FileSystemDefaultEncoding" should be used as the encoding, and
"Py_FileSystemDefaultEncodeErrors" should be used as the error handler
(**PEP 383** and **PEP 529**). To encode file names to "bytes" during
argument parsing, the ""O&"" converter should be used, passing
"PyUnicode_FSConverter()" as the conversion function:

int PyUnicode_FSConverter(PyObject *obj, void *result)
    * Part of the Stable ABI.*

   ParseTuple converter: encode "str" objects -- obtained directly or
   through the "os.PathLike" interface -- to "bytes" using
   "PyUnicode_EncodeFSDefault()"; "bytes" objects are output as-is.
   *result* must be a "PyBytesObject*" which must be released when it
   is no longer used.

   3.1 版新加入.

   3.6 版更變: 接受一个 *path-like object*。

To decode file names to "str" during argument parsing, the ""O&""
converter should be used, passing "PyUnicode_FSDecoder()" as the
conversion function:

int PyUnicode_FSDecoder(PyObject *obj, void *result)
    * Part of the Stable ABI.*

   ParseTuple converter: decode "bytes" objects -- obtained either
   directly or indirectly through the "os.PathLike" interface -- to
   "str" using "PyUnicode_DecodeFSDefaultAndSize()"; "str" objects are
   output as-is. *result* must be a "PyUnicodeObject*" which must be
   released when it is no longer used.

   3.2 版新加入.

   3.6 版更變: 接受一个 *path-like object*。

PyObject *PyUnicode_DecodeFSDefaultAndSize(const char *s, Py_ssize_t size)
    *返回值：新的引用。** Part of the Stable ABI.*

   Decode a string from the *filesystem encoding and error handler*.

   If "Py_FileSystemDefaultEncoding" is not set, fall back to the
   locale encoding.

   "Py_FileSystemDefaultEncoding" is initialized at startup from the
   locale encoding and cannot be modified later. If you need to decode
   a string from the current locale encoding, use
   "PyUnicode_DecodeLocaleAndSize()".

   也參考: "Py_DecodeLocale()" 函式。

   3.6 版更變: Use "Py_FileSystemDefaultEncodeErrors" error handler.

PyObject *PyUnicode_DecodeFSDefault(const char *s)
    *返回值：新的引用。** Part of the Stable ABI.*

   Decode a null-terminated string from the *filesystem encoding and
   error handler*.

   If "Py_FileSystemDefaultEncoding" is not set, fall back to the
   locale encoding.

   Use "PyUnicode_DecodeFSDefaultAndSize()" if you know the string
   length.

   3.6 版更變: Use "Py_FileSystemDefaultEncodeErrors" error handler.

PyObject *PyUnicode_EncodeFSDefault(PyObject *unicode)
    *返回值：新的引用。** Part of the Stable ABI.*

   Encode a Unicode object to "Py_FileSystemDefaultEncoding" with the
   "Py_FileSystemDefaultEncodeErrors" error handler, and return
   "bytes". Note that the resulting "bytes" object may contain null
   bytes.

   If "Py_FileSystemDefaultEncoding" is not set, fall back to the
   locale encoding.

   "Py_FileSystemDefaultEncoding" is initialized at startup from the
   locale encoding and cannot be modified later. If you need to encode
   a string to the current locale encoding, use
   "PyUnicode_EncodeLocale()".

   也參考: "Py_EncodeLocale()" 函式。

   3.2 版新加入.

   3.6 版更變: Use "Py_FileSystemDefaultEncodeErrors" error handler.


wchar_t Support
---------------

"wchar_t" support for platforms which support it:

PyObject *PyUnicode_FromWideChar(const wchar_t *w, Py_ssize_t size)
    *返回值：新的引用。** Part of the Stable ABI.*

   Create a Unicode object from the "wchar_t" buffer *w* of the given
   *size*. Passing "-1" as the *size* indicates that the function must
   itself compute the length, using wcslen. Return "NULL" on failure.

Py_ssize_t PyUnicode_AsWideChar(PyObject *unicode, wchar_t *w, Py_ssize_t size)
    * Part of the Stable ABI.*

   Copy the Unicode object contents into the "wchar_t" buffer *w*.  At
   most *size* "wchar_t" characters are copied (excluding a possibly
   trailing null termination character).  Return the number of
   "wchar_t" characters copied or "-1" in case of an error.  Note that
   the resulting "wchar_t*" string may or may not be null-terminated.
   It is the responsibility of the caller to make sure that the
   "wchar_t*" string is null-terminated in case this is required by
   the application. Also, note that the "wchar_t*" string might
   contain null characters, which would cause the string to be
   truncated when used with most C functions.

wchar_t *PyUnicode_AsWideCharString(PyObject *unicode, Py_ssize_t *size)
    * Part of the Stable ABI since version 3.7.*

   Convert the Unicode object to a wide character string. The output
   string always ends with a null character. If *size* is not "NULL",
   write the number of wide characters (excluding the trailing null
   termination character) into **size*. Note that the resulting
   "wchar_t" string might contain null characters, which would cause
   the string to be truncated when used with most C functions. If
   *size* is "NULL" and the "wchar_t*" string contains null characters
   a "ValueError" is raised.

   Returns a buffer allocated by "PyMem_Alloc()" (use "PyMem_Free()"
   to free it) on success. On error, returns "NULL" and **size* is
   undefined. Raises a "MemoryError" if memory allocation is failed.

   3.2 版新加入.

   3.7 版更變: Raises a "ValueError" if *size* is "NULL" and the
   "wchar_t*" string contains null characters.


Built-in Codecs
===============

Python provides a set of built-in 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, and
they have the same semantics as the ones of the built-in "str()"
string object constructor.

Setting encoding to "NULL" causes the default encoding to be used
which is UTF-8.  The file system calls should use
"PyUnicode_FSConverter()" for encoding file names. This uses the
variable "Py_FileSystemDefaultEncoding" internally. 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 built-in codecs is "strict" ("ValueError" is
raised).

The codecs all use a similar interface.  Only deviations from the
following generic ones are documented for simplicity.


Generic Codecs
--------------

These are the generic codec APIs:

PyObject *PyUnicode_Decode(const char *s, Py_ssize_t size, const char *encoding, const char *errors)
    *返回值：新的引用。** Part of the Stable ABI.*

   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 "str()" 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.

PyObject *PyUnicode_AsEncodedString(PyObject *unicode, const char *encoding, const char *errors)
    *返回值：新的引用。** Part of the Stable ABI.*

   Encode a Unicode object and return the result as Python bytes
   object. *encoding* and *errors* have the same meaning as the
   parameters of the same name in the Unicode "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.

PyObject *PyUnicode_Encode(const Py_UNICODE *s, Py_ssize_t size, const char *encoding, const char *errors)
    *返回值：新的引用。*

   Encode the "Py_UNICODE" buffer *s* of the given *size* and return a
   Python bytes object.  *encoding* and *errors* have the same meaning
   as the parameters of the same name in the Unicode "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.

   自從版本 3.3 後不推薦使用，將會自版本 3.11 中移除。: Part of the
   old-style "Py_UNICODE" API; please migrate to using
   "PyUnicode_AsEncodedString()".


UTF-8 编解码器
--------------

以下是 UTF-8 编解码器 API:

PyObject *PyUnicode_DecodeUTF8(const char *s, Py_ssize_t size, const char *errors)
    *返回值：新的引用。** Part of the Stable ABI.*

   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.

PyObject *PyUnicode_DecodeUTF8Stateful(const char *s, Py_ssize_t size, const char *errors, Py_ssize_t *consumed)
    *返回值：新的引用。** Part of the Stable ABI.*

   If *consumed* is "NULL", behave like "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*.

PyObject *PyUnicode_AsUTF8String(PyObject *unicode)
    *返回值：新的引用。** Part of the Stable ABI.*

   Encode a Unicode object using UTF-8 and return the result as Python
   bytes object.  Error handling is "strict".  Return "NULL" if an
   exception was raised by the codec.

const char *PyUnicode_AsUTF8AndSize(PyObject *unicode, Py_ssize_t *size)
    * Part of the Stable ABI since version 3.10.*

   Return a pointer to the UTF-8 encoding of the Unicode object, and
   store the size of the encoded representation (in bytes) in *size*.
   The *size* argument can be "NULL"; in this case no size will be
   stored.  The returned buffer always has an extra null byte appended
   (not included in *size*), regardless of whether there are any other
   null code points.

   In the case of an error, "NULL" is returned with an exception set
   and no *size* is stored.

   This caches the UTF-8 representation of the string in the Unicode
   object, and subsequent calls will return a pointer to the same
   buffer.  The caller is not responsible for deallocating the buffer.
   The buffer is deallocated and pointers to it become invalid when
   the Unicode object is garbage collected.

   3.3 版新加入.

   3.7 版更變: The return type is now "const char *" rather of "char
   *".

   3.10 版更變: This function is a part of the limited API.

const char *PyUnicode_AsUTF8(PyObject *unicode)

   As "PyUnicode_AsUTF8AndSize()", but does not store the size.

   3.3 版新加入.

   3.7 版更變: The return type is now "const char *" rather of "char
   *".

PyObject *PyUnicode_EncodeUTF8(const Py_UNICODE *s, Py_ssize_t size, const char *errors)
    *返回值：新的引用。*

   Encode the "Py_UNICODE" buffer *s* of the given *size* using UTF-8
   and return a Python bytes object.  Return "NULL" if an exception
   was raised by the codec.

   自從版本 3.3 後不推薦使用，將會自版本 3.11 中移除。: Part of the
   old-style "Py_UNICODE" API; please migrate to using
   "PyUnicode_AsUTF8String()", "PyUnicode_AsUTF8AndSize()" or
   "PyUnicode_AsEncodedString()".


UTF-32 Codecs
-------------

These are the UTF-32 codec APIs:

PyObject *PyUnicode_DecodeUTF32(const char *s, Py_ssize_t size, const char *errors, int *byteorder)
    *返回值：新的引用。** Part of the Stable ABI.*

   Decode *size* 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

   If "*byteorder" is zero, and the first four bytes of the input data
   are a byte order mark (BOM), the decoder switches to this byte
   order and the BOM is not copied into the resulting Unicode string.
   If "*byteorder" is "-1" or "1", any byte order mark is copied to
   the output.

   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.

PyObject *PyUnicode_DecodeUTF32Stateful(const char *s, Py_ssize_t size, const char *errors, int *byteorder, Py_ssize_t *consumed)
    *返回值：新的引用。** Part of the Stable ABI.*

   If *consumed* is "NULL", behave like "PyUnicode_DecodeUTF32()". If
   *consumed* is not "NULL", "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*.

PyObject *PyUnicode_AsUTF32String(PyObject *unicode)
    *返回值：新的引用。** Part of the Stable ABI.*

   Return a Python byte 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.

PyObject *PyUnicode_EncodeUTF32(const Py_UNICODE *s, Py_ssize_t size, const char *errors, int byteorder)
    *返回值：新的引用。*

   Return a Python bytes object holding the UTF-32 encoded value of
   the Unicode data in *s*.  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 code point.

   Return "NULL" if an exception was raised by the codec.

   自從版本 3.3 後不推薦使用，將會自版本 3.11 中移除。: Part of the
   old-style "Py_UNICODE" API; please migrate to using
   "PyUnicode_AsUTF32String()" or "PyUnicode_AsEncodedString()".


UTF-16 Codecs
-------------

These are the UTF-16 codec APIs:

PyObject *PyUnicode_DecodeUTF16(const char *s, Py_ssize_t size, const char *errors, int *byteorder)
    *返回值：新的引用。** Part of the Stable ABI.*

   Decode *size* 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

   If "*byteorder" is zero, and the first two bytes of the input data
   are a byte order mark (BOM), the decoder switches to this byte
   order and the BOM is not copied into the resulting Unicode string.
   If "*byteorder" is "-1" or "1", any byte order mark is copied to
   the output (where it will result in either a "\ufeff" or a "\ufffe"
   character).

   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.

PyObject *PyUnicode_DecodeUTF16Stateful(const char *s, Py_ssize_t size, const char *errors, int *byteorder, Py_ssize_t *consumed)
    *返回值：新的引用。** Part of the Stable ABI.*

   If *consumed* is "NULL", behave like "PyUnicode_DecodeUTF16()". If
   *consumed* is not "NULL", "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*.

PyObject *PyUnicode_AsUTF16String(PyObject *unicode)
    *返回值：新的引用。** Part of the Stable ABI.*

   Return a Python byte 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.

PyObject *PyUnicode_EncodeUTF16(const Py_UNICODE *s, Py_ssize_t size, const char *errors, int byteorder)
    *返回值：新的引用。*

   Return a Python bytes object holding the UTF-16 encoded value of
   the Unicode data in *s*.  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 "Py_UNICODE" value may
   get represented as a surrogate pair. If it is not defined, each
   "Py_UNICODE" values is interpreted as a UCS-2 character.

   Return "NULL" if an exception was raised by the codec.

   自從版本 3.3 後不推薦使用，將會自版本 3.11 中移除。: Part of the
   old-style "Py_UNICODE" API; please migrate to using
   "PyUnicode_AsUTF16String()" or "PyUnicode_AsEncodedString()".


UTF-7 Codecs
------------

These are the UTF-7 codec APIs:

PyObject *PyUnicode_DecodeUTF7(const char *s, Py_ssize_t size, const char *errors)
    *返回值：新的引用。** Part of the Stable ABI.*

   Create a Unicode object by decoding *size* bytes of the UTF-7
   encoded string *s*.  Return "NULL" if an exception was raised by
   the codec.

PyObject *PyUnicode_DecodeUTF7Stateful(const char *s, Py_ssize_t size, const char *errors, Py_ssize_t *consumed)
    *返回值：新的引用。** Part of the Stable ABI.*

   If *consumed* is "NULL", behave like "PyUnicode_DecodeUTF7()".  If
   *consumed* is not "NULL", trailing incomplete UTF-7 base-64
   sections 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*.

PyObject *PyUnicode_EncodeUTF7(const Py_UNICODE *s, Py_ssize_t size, int base64SetO, int base64WhiteSpace, const char *errors)
    *返回值：新的引用。*

   Encode the "Py_UNICODE" buffer of the given size using UTF-7 and
   return a Python bytes object.  Return "NULL" if an exception was
   raised by the codec.

   If *base64SetO* is nonzero, "Set O" (punctuation that has no
   otherwise special meaning) will be encoded in base-64.  If
   *base64WhiteSpace* is nonzero, whitespace will be encoded in
   base-64.  Both are set to zero for the Python "utf-7" codec.

   自從版本 3.3 後不推薦使用，將會自版本 3.11 中移除。: Part of the
   old-style "Py_UNICODE" API; please migrate to using
   "PyUnicode_AsEncodedString()".


Unicode-Escape 编解码器
-----------------------

These are the "Unicode Escape" codec APIs:

PyObject *PyUnicode_DecodeUnicodeEscape(const char *s, Py_ssize_t size, const char *errors)
    *返回值：新的引用。** Part of the Stable ABI.*

   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.

PyObject *PyUnicode_AsUnicodeEscapeString(PyObject *unicode)
    *返回值：新的引用。** Part of the Stable ABI.*

   Encode a Unicode object using Unicode-Escape and return the result
   as a bytes object.  Error handling is "strict".  Return "NULL" if
   an exception was raised by the codec.

PyObject *PyUnicode_EncodeUnicodeEscape(const Py_UNICODE *s, Py_ssize_t size)
    *返回值：新的引用。*

   Encode the "Py_UNICODE" buffer of the given *size* using Unicode-
   Escape and return a bytes object.  Return "NULL" if an exception
   was raised by the codec.

   自從版本 3.3 後不推薦使用，將會自版本 3.11 中移除。: Part of the
   old-style "Py_UNICODE" API; please migrate to using
   "PyUnicode_AsUnicodeEscapeString()".


Raw-Unicode-Escape Codecs
-------------------------

These are the "Raw Unicode Escape" codec APIs:

PyObject *PyUnicode_DecodeRawUnicodeEscape(const char *s, Py_ssize_t size, const char *errors)
    *返回值：新的引用。** Part of the Stable ABI.*

   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.

PyObject *PyUnicode_AsRawUnicodeEscapeString(PyObject *unicode)
    *返回值：新的引用。** Part of the Stable ABI.*

   Encode a Unicode object using Raw-Unicode-Escape and return the
   result as a bytes object.  Error handling is "strict".  Return
   "NULL" if an exception was raised by the codec.

PyObject *PyUnicode_EncodeRawUnicodeEscape(const Py_UNICODE *s, Py_ssize_t size)
    *返回值：新的引用。*

   Encode the "Py_UNICODE" buffer of the given *size* using Raw-
   Unicode-Escape and return a bytes object.  Return "NULL" if an
   exception was raised by the codec.

   自從版本 3.3 後不推薦使用，將會自版本 3.11 中移除。: Part of the
   old-style "Py_UNICODE" API; please migrate to using
   "PyUnicode_AsRawUnicodeEscapeString()" or
   "PyUnicode_AsEncodedString()".


Latin-1 Codecs
--------------

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.

PyObject *PyUnicode_DecodeLatin1(const char *s, Py_ssize_t size, const char *errors)
    *返回值：新的引用。** Part of the Stable ABI.*

   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.

PyObject *PyUnicode_AsLatin1String(PyObject *unicode)
    *返回值：新的引用。** Part of the Stable ABI.*

   Encode a Unicode object using Latin-1 and return the result as
   Python bytes object.  Error handling is "strict".  Return "NULL" if
   an exception was raised by the codec.

PyObject *PyUnicode_EncodeLatin1(const Py_UNICODE *s, Py_ssize_t size, const char *errors)
    *返回值：新的引用。*

   Encode the "Py_UNICODE" buffer of the given *size* using Latin-1
   and return a Python bytes object.  Return "NULL" if an exception
   was raised by the codec.

   自從版本 3.3 後不推薦使用，將會自版本 3.11 中移除。: Part of the
   old-style "Py_UNICODE" API; please migrate to using
   "PyUnicode_AsLatin1String()" or "PyUnicode_AsEncodedString()".


ASCII Codecs
------------

These are the ASCII codec APIs.  Only 7-bit ASCII data is accepted.
All other codes generate errors.

PyObject *PyUnicode_DecodeASCII(const char *s, Py_ssize_t size, const char *errors)
    *返回值：新的引用。** Part of the Stable ABI.*

   Create a Unicode object by decoding *size* bytes of the ASCII
   encoded string *s*.  Return "NULL" if an exception was raised by
   the codec.

PyObject *PyUnicode_AsASCIIString(PyObject *unicode)
    *返回值：新的引用。** Part of the Stable ABI.*

   Encode a Unicode object using ASCII and return the result as Python
   bytes object.  Error handling is "strict".  Return "NULL" if an
   exception was raised by the codec.

PyObject *PyUnicode_EncodeASCII(const Py_UNICODE *s, Py_ssize_t size, const char *errors)
    *返回值：新的引用。*

   Encode the "Py_UNICODE" buffer of the given *size* using ASCII and
   return a Python bytes object.  Return "NULL" if an exception was
   raised by the codec.

   自從版本 3.3 後不推薦使用，將會自版本 3.11 中移除。: Part of the
   old-style "Py_UNICODE" API; please migrate to using
   "PyUnicode_AsASCIIString()" or "PyUnicode_AsEncodedString()".


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 "encodings" package). The codec
uses mappings to encode and decode characters.  The mapping objects
provided must support the "__getitem__()" mapping interface;
dictionaries and sequences work well.

These are the mapping codec APIs:

PyObject *PyUnicode_DecodeCharmap(const char *data, Py_ssize_t size, PyObject *mapping, const char *errors)
    *返回值：新的引用。** Part of the Stable ABI.*

   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 applied.  Else
   *mapping* must map bytes ordinals (integers in the range from 0 to
   255) to Unicode strings, integers (which are then interpreted as
   Unicode ordinals) or "None".  Unmapped data bytes -- ones which
   cause a "LookupError", as well as ones which get mapped to "None",
   "0xFFFE" or "'\ufffe'", are treated as undefined mappings and cause
   an error.

PyObject *PyUnicode_AsCharmapString(PyObject *unicode, PyObject *mapping)
    *返回值：新的引用。** Part of the Stable ABI.*

   Encode a Unicode object using the given *mapping* object and return
   the result as a bytes object.  Error handling is "strict".  Return
   "NULL" if an exception was raised by the codec.

   The *mapping* object must map Unicode ordinal integers to bytes
   objects, integers in the range from 0 to 255 or "None".  Unmapped
   character ordinals (ones which cause a "LookupError") as well as
   mapped to "None" are treated as "undefined mapping" and cause an
   error.

PyObject *PyUnicode_EncodeCharmap(const Py_UNICODE *s, Py_ssize_t size, PyObject *mapping, const char *errors)
    *返回值：新的引用。*

   Encode the "Py_UNICODE" buffer of the given *size* using the given
   *mapping* object and return the result as a bytes object.  Return
   "NULL" if an exception was raised by the codec.

   自從版本 3.3 後不推薦使用，將會自版本 3.11 中移除。: Part of the
   old-style "Py_UNICODE" API; please migrate to using
   "PyUnicode_AsCharmapString()" or "PyUnicode_AsEncodedString()".

The following codec API is special in that maps Unicode to Unicode.

PyObject *PyUnicode_Translate(PyObject *str, PyObject *table, const char *errors)
    *返回值：新的引用。** Part of the Stable ABI.*

   Translate a string by applying a character mapping table to it and
   return the resulting Unicode object. Return "NULL" if 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 "__getitem__()" interface;
   dictionaries and sequences work well.  Unmapped character ordinals
   (ones which cause a "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.

PyObject *PyUnicode_TranslateCharmap(const Py_UNICODE *s, Py_ssize_t size, PyObject *mapping, const char *errors)
    *返回值：新的引用。*

   Translate a "Py_UNICODE" buffer of the given *size* by applying a
   character *mapping* table to it and return the resulting Unicode
   object. Return "NULL" when an exception was raised by the codec.

   自從版本 3.3 後不推薦使用，將會自版本 3.11 中移除。: Part of the
   old-style "Py_UNICODE" API; please migrate to using
   "PyUnicode_Translate()". or generic codec based API


MBCS codecs for Windows
-----------------------

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.

PyObject *PyUnicode_DecodeMBCS(const char *s, Py_ssize_t size, const char *errors)
    *返回值：新的引用。** Part of the Stable ABI on Windows since
   version 3.7.*

   Create a Unicode object by decoding *size* bytes of the MBCS
   encoded string *s*. Return "NULL" if an exception was raised by the
   codec.

PyObject *PyUnicode_DecodeMBCSStateful(const char *s, Py_ssize_t size, const char *errors, Py_ssize_t *consumed)
    *返回值：新的引用。** Part of the Stable ABI on Windows since
   version 3.7.*

   If *consumed* is "NULL", behave like "PyUnicode_DecodeMBCS()". If
   *consumed* is not "NULL", "PyUnicode_DecodeMBCSStateful()" will not
   decode trailing lead byte and the number of bytes that have been
   decoded will be stored in *consumed*.

PyObject *PyUnicode_AsMBCSString(PyObject *unicode)
    *返回值：新的引用。** Part of the Stable ABI on Windows since
   version 3.7.*

   Encode a Unicode object using MBCS and return the result as Python
   bytes object.  Error handling is "strict".  Return "NULL" if an
   exception was raised by the codec.

PyObject *PyUnicode_EncodeCodePage(int code_page, PyObject *unicode, const char *errors)
    *返回值：新的引用。** Part of the Stable ABI on Windows since
   version 3.7.*

   Encode the Unicode object using the specified code page and return
   a Python bytes object.  Return "NULL" if an exception was raised by
   the codec. Use "CP_ACP" code page to get the MBCS encoder.

   3.3 版新加入.

PyObject *PyUnicode_EncodeMBCS(const Py_UNICODE *s, Py_ssize_t size, const char *errors)
    *返回值：新的引用。*

   Encode the "Py_UNICODE" buffer of the given *size* using MBCS and
   return a Python bytes object.  Return "NULL" if an exception was
   raised by the codec.

   自從版本 3.3 後不推薦使用，將會自版本 4.0 中移除。: Part of the
   old-style "Py_UNICODE" API; please migrate to using
   "PyUnicode_AsMBCSString()", "PyUnicode_EncodeCodePage()" or
   "PyUnicode_AsEncodedString()".


Methods & Slots
---------------


方法与槽位函数
==============

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.

PyObject *PyUnicode_Concat(PyObject *left, PyObject *right)
    *返回值：新的引用。** Part of the Stable ABI.*

   Concat two strings giving a new Unicode string.

PyObject *PyUnicode_Split(PyObject *s, PyObject *sep, Py_ssize_t maxsplit)
    *返回值：新的引用。** Part of the Stable ABI.*

   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.

PyObject *PyUnicode_Splitlines(PyObject *s, int keepend)
    *返回值：新的引用。** Part of the Stable ABI.*

   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.

PyObject *PyUnicode_Join(PyObject *separator, PyObject *seq)
    *返回值：新的引用。** Part of the Stable ABI.*

   Join a sequence of strings using the given *separator* and return
   the resulting Unicode string.

Py_ssize_t PyUnicode_Tailmatch(PyObject *str, PyObject *substr, Py_ssize_t start, Py_ssize_t end, int direction)
    * Part of the Stable ABI.*

   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.

Py_ssize_t PyUnicode_Find(PyObject *str, PyObject *substr, Py_ssize_t start, Py_ssize_t end, int direction)
    * Part of the Stable ABI.*

   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.

Py_ssize_t PyUnicode_FindChar(PyObject *str, Py_UCS4 ch, Py_ssize_t start, Py_ssize_t end, int direction)
    * Part of the Stable ABI since version 3.7.*

   Return the first position of the character *ch* 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.

   3.3 版新加入.

   3.7 版更變: *start* and *end* are now adjusted to behave like
   "str[start:end]".

Py_ssize_t PyUnicode_Count(PyObject *str, PyObject *substr, Py_ssize_t start, Py_ssize_t end)
    * Part of the Stable ABI.*

   Return the number of non-overlapping occurrences of *substr* in
   "str[start:end]".  Return "-1" if an error occurred.

PyObject *PyUnicode_Replace(PyObject *str, PyObject *substr, PyObject *replstr, Py_ssize_t maxcount)
    *返回值：新的引用。** Part of the Stable ABI.*

   Replace at most *maxcount* occurrences of *substr* in *str* with
   *replstr* and return the resulting Unicode object. *maxcount* ==
   "-1" means replace all occurrences.

int PyUnicode_Compare(PyObject *left, PyObject *right)
    * Part of the Stable ABI.*

   Compare two strings and return "-1", "0", "1" for less than, equal,
   and greater than, respectively.

   This function returns "-1" upon failure, so one should call
   "PyErr_Occurred()" to check for errors.

int PyUnicode_CompareWithASCIIString(PyObject *uni, const char *string)
    * Part of the Stable ABI.*

   Compare a Unicode object, *uni*, with *string* and return "-1",
   "0", "1" for less than, equal, and greater than, respectively. It
   is best to pass only ASCII-encoded strings, but the function
   interprets the input string as ISO-8859-1 if it contains non-ASCII
   characters.

   This function does not raise exceptions.

PyObject *PyUnicode_RichCompare(PyObject *left, PyObject *right, int op)
    *返回值：新的引用。** Part of the Stable ABI.*

   对两个 Unicode 字符串执行富比较并返回以下值之一:

   * "NULL" in case an exception was raised

   * "Py_True" or "Py_False" for successful comparisons

   * "Py_NotImplemented" in case the type combination is unknown

   Possible values for *op* are "Py_GT", "Py_GE", "Py_EQ", "Py_NE",
   "Py_LT", and "Py_LE".

PyObject *PyUnicode_Format(PyObject *format, PyObject *args)
    *返回值：新的引用。** Part of the Stable ABI.*

   Return a new string object from *format* and *args*; this is
   analogous to "format % args".

int PyUnicode_Contains(PyObject *container, PyObject *element)
    * Part of the Stable ABI.*

   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.

void PyUnicode_InternInPlace(PyObject **string)
    * Part of the Stable ABI.*

   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 (releasing the reference to
   the old string object and creating a new *strong reference* to the
   interned string object), otherwise it leaves **string* alone and
   interns it (creating a new *strong reference*). (Clarification:
   even though there is a lot of talk about references, think of this
   function as reference-neutral; you own the object after the call if
   and only if you owned it before the call.)

PyObject *PyUnicode_InternFromString(const char *v)
    *返回值：新的引用。** Part of the Stable ABI.*

   A combination of "PyUnicode_FromString()" and
   "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.
