Since the implementation of PEP 393 in Python 3.3, Unicode objects internally use a variety of representations, in order to allow handling the complete range of Unicode characters while staying memory efficient. There are special cases for strings where all code points are below 128, 256, or 65536; otherwise, code points must be below 1114112 (which is the full Unicode range).
UTF-8 representation is created on demand and cached in the Unicode object.
注意
The Py_UNICODE representation has been removed since Python 3.12 with deprecated APIs. See PEP 623 了解更多信息。
Py_UNICODE
These are the basic Unicode object types used for the Unicode implementation in Python:
These types are typedefs for unsigned integer types wide enough to contain characters of 32 bits, 16 bits and 8 bits, respectively. When dealing with single Unicode characters, use Py_UCS4 .
Py_UCS4
Added in version 3.3.
This is a typedef of wchar_t , which is a 16-bit type or 32-bit type depending on the platform.
wchar_t
3.3 版改变： In previous versions, this was a 16-bit type or a 32-bit type depending on whether you selected a “narrow” or “wide” Unicode version of Python at build time.
These subtypes of PyObject represent a Python Unicode object. In almost all cases, they shouldn’t be used directly, since all API functions that deal with Unicode objects take and return PyObject pointers.
PyObject
此实例的 PyTypeObject represents the Python Unicode type. It is exposed to Python code as str .
PyTypeObject
str
The following APIs are C macros and static inlined functions for fast checks and access to internal read-only data of Unicode objects:
Return true if the object obj is a Unicode object or an instance of a Unicode subtype. This function always succeeds.
Return true if the object obj is a Unicode object, but not an instance of a subtype. This function always succeeds.
返回 0 . This API is kept only for backward compatibility.
0
从 3.10 版起弃用： This API does nothing since Python 3.12.
Return the length of the Unicode string, in code points. unicode has to be a Unicode object in the “canonical” representation (not checked).
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 function.
PyUnicode_KIND()
Return values of the PyUnicode_KIND() 宏。
Changed in version 3.12: PyUnicode_WCHAR_KIND 已被移除。
PyUnicode_WCHAR_KIND
Return one of the PyUnicode kind constants (see above) that indicate how many bytes per character this Unicode object uses to store its data. unicode has to be a Unicode object in the “canonical” representation (not checked).
Return a void pointer to the raw Unicode buffer. unicode has to be a Unicode object in the “canonical” representation (not checked).
Write into a canonical representation data (as obtained with PyUnicode_DATA() ). This function performs no sanity checks, and is intended for usage in loops. The caller should cache the kind value and data pointer as obtained from other 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.
PyUnicode_DATA()
Read a code point from a canonical representation data (as obtained with PyUnicode_DATA() ). No checks or ready calls are performed.
Read a character from a Unicode object unicode , which must be in the “canonical” representation. This is less efficient than PyUnicode_READ() if you do multiple consecutive reads.
PyUnicode_READ()
Return the maximum code point that is suitable for creating another string based on unicode , which must be in the “canonical” representation. This is always an approximation but more efficient than iterating over the string.
返回 1 若字符串是根据语言定义的有效标识符，章节 标识符和关键词 。返回 0 否则。
1
3.9 版改变： The function does not call Py_FatalError() anymore if the string is not ready.
Py_FatalError()
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.
返回 1 or 0 depending on whether ch is a whitespace character.
返回 1 or 0 depending on whether ch is a lowercase character.
返回 1 or 0 depending on whether ch is an uppercase character.
返回 1 or 0 depending on whether ch is a titlecase character.
返回 1 or 0 depending on whether ch is a linebreak character.
返回 1 or 0 depending on whether ch is a decimal character.
返回 1 or 0 depending on whether ch is a digit character.
返回 1 or 0 depending on whether ch is a numeric character.
返回 1 or 0 depending on whether ch is an alphabetic character.
返回 1 or 0 depending on whether ch is an alphanumeric character.
返回 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 )。
repr()
sys.stdout
sys.stderr
These APIs can be used for fast direct character conversions:
Return the character ch converted to lower case.
从 3.3 版起弃用： This function uses simple case mappings.
Return the character ch converted to upper case.
Return the character ch converted to title case.
Return the character ch converted to a decimal positive integer. Return -1 if this is not possible. This function does not raise exceptions.
-1
Return the character ch converted to a single digit integer. Return -1 if this is not possible. This function does not raise exceptions.
Return the character ch converted to a double. Return -1.0 if this is not possible. This function does not raise exceptions.
-1.0
These APIs can be used to work with surrogates:
Check if ch is a surrogate ( 0xD800 <= ch <= 0xDFFF ).
0xD800 <= ch <= 0xDFFF
Check if ch is a high surrogate ( 0xD800 <= ch <= 0xDBFF ).
0xD800 <= ch <= 0xDBFF
Check if ch is a low surrogate ( 0xDC00 <= ch <= 0xDFFF ).
0xDC00 <= ch <= 0xDFFF
Join two surrogate characters and return a single Py_UCS4 值。 high and low are respectively the leading and trailing surrogates in a surrogate pair. high must be in the range [0xD800; 0xDBFF] and low must be in the range [0xDC00; 0xDFFF].
To create Unicode objects and access their basic sequence properties, use these APIs:
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.
Create a new Unicode object with the given kind (possible values are PyUnicode_1BYTE_KIND etc., as returned by PyUnicode_KIND() )。 buffer must point to an array of size units of 1, 2 or 4 bytes per character, as given by the kind.
PyUnicode_1BYTE_KIND
If necessary, the input buffer is copied and transformed into the canonical representation. For example, if the buffer is a UCS4 string ( PyUnicode_4BYTE_KIND ) and it consists only of codepoints in the UCS1 range, it will be transformed into UCS1 ( PyUnicode_1BYTE_KIND ).
PyUnicode_4BYTE_KIND
Create a Unicode object from the char buffer str . The bytes will be interpreted as being UTF-8 encoded. The buffer is copied into the new object. The return value might be a shared object, i.e. modification of the data is not allowed.
此函数引发 SystemError when:
SystemError
size < 0,
str is NULL and size > 0
NULL
Changed in version 3.12: str == NULL with size > 0 is not allowed anymore.
Create a Unicode object from a UTF-8 encoded null-terminated char buffer str .
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.
printf()
A conversion specifier contains two or more characters and has the following components, which must occur in this order:
The '%' character, which marks the start of the specifier.
'%'
Conversion flags (optional), which affect the result of some conversion types.
Minimum field width (optional). If specified as an '*' (asterisk), the actual width is given in the next argument, which must be of type int , and the object to convert comes after the minimum field width and optional precision.
'*'
Precision (optional), given as a '.' (dot) followed by the precision. If specified as '*' (an asterisk), the actual precision is given in the next argument, which must be of type int , and the value to convert comes after the precision.
'.'
Length modifier (optional).
转换类型。
转换标志字符：
标志
含义
-
The converted value is left adjusted (overrides the 0 flag if both are given).
The length modifiers for following integer conversions ( d , i , o , u , x ，或 X ) specify the type of the argument ( int by default):
d
i
o
u
x
X
Modifier
类型
l
long or unsigned long
ll
long long or unsigned long long
j
intmax_t or uintmax_t
intmax_t
uintmax_t
z
size_t or ssize_t
size_t
ssize_t
t
ptrdiff_t
The length modifier l for following conversions s or V specify that the type of the argument is const wchar_t * .
s
V
The conversion specifiers are:
Conversion Specifier
注释
%
n/a
The literal % 字符。
d , i
c
int
const char * or const wchar_t *
p
const 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.
printf("%p")
0x
printf
A
PyObject *
The result of calling ascii() .
ascii()
U
PyObject * , const char * or const wchar_t *
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 ).
S
The result of calling PyObject_Str() .
PyObject_Str()
R
The result of calling PyObject_Repr() .
PyObject_Repr()
The width formatter unit is number of characters rather than bytes. The precision formatter unit is number of bytes or wchar_t items (if the length modifier l is used) for "%s" and "%V" (if the PyObject* 自变量为 NULL ), and a number of characters for "%A" , "%U" , "%S" , "%R" and "%V" (if the PyObject* argument is not NULL ).
"%s"
"%V"
PyObject*
"%A"
"%U"
"%S"
"%R"
Unlike to C printf() the 0 flag has effect even when a precision is given for integer conversions ( d , i , u , o , x ，或 X ).
3.2 版改变： 支持 "%lld" and "%llu" added.
"%lld"
"%llu"
3.3 版改变： 支持 "%li" , "%lli" and "%zi" added.
"%li"
"%lli"
"%zi"
3.4 版改变： Support width and precision formatter for "%s" , "%A" , "%U" , "%V" , "%S" , "%R" added.
Changed in version 3.12: Support for conversion specifiers o and X . Support for length modifiers j and t . Length modifiers are now applied to all integer conversions. Length modifier l is now applied to conversion specifiers s and V . Support for variable width and precision * . Support for flag - .
*
An unrecognized format character now sets a SystemError . In previous versions it caused all the rest of the format string to be copied as-is to the result string, and any extra arguments discarded.
等同于 PyUnicode_FromFormat() except that it takes exactly two arguments.
PyUnicode_FromFormat()
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 a new 强引用 to the object.
Objects other than Unicode or its subtypes will cause a TypeError .
TypeError
Decode an encoded object obj to a Unicode object.
bytes , bytearray and other 像字节对象 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 内置编解码器 了解细节)。
bytes
bytearray
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.
Return the length of the Unicode object, in code points.
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.
memcpy()
Fill a string with a character: write fill_char into unicode[start:start+length] .
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.
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.
PyUnicode_New()
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).
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 PyUnicode_READ_CHAR() , which performs no error checking.
PyUnicode_READ_CHAR()
Return a substring of unicode , from character index start (included) to character index end (excluded). Negative indices are not supported.
Copy the string unicode 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 unicode ). buffer 被返回当成功时。
Copy the string unicode 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.
PyMem_Malloc()
MemoryError
The current locale encoding can be used to decode text from the operating system.
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.
"strict"
"surrogateescape"
使用 PyUnicode_DecodeFSDefaultAndSize() to decode a string from the 文件系统编码和错误处理程序 .
PyUnicode_DecodeFSDefaultAndSize()
This function ignores the Python UTF-8 模式 .
另请参阅
The Py_DecodeLocale() 函数。
Py_DecodeLocale()
3.7 版改变： 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 .
surrogateescape
strict
类似于 PyUnicode_DecodeLocaleAndSize() , but compute the string length using strlen() .
PyUnicode_DecodeLocaleAndSize()
strlen()
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 。返回 bytes 对象。 unicode cannot contain embedded null characters.
使用 PyUnicode_EncodeFSDefault() to encode a string to the 文件系统编码和错误处理程序 .
PyUnicode_EncodeFSDefault()
The Py_EncodeLocale() 函数。
Py_EncodeLocale()
3.7 版改变： 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 .
Functions encoding to and decoding from the 文件系统编码和错误处理程序 ( 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:
"O&"
PyUnicode_FSConverter()
ParseTuple converter: encode str objects – obtained directly or through the os.PathLike interface – to bytes 使用 PyUnicode_EncodeFSDefault() ; bytes objects are output as-is. result 必须为 PyBytesObject * which must be released when it is no longer used.
os.PathLike
Added in version 3.1.
3.6 版改变： 接受 像路径对象 .
To decode file names to str during argument parsing, the "O&" converter should be used, passing PyUnicode_FSDecoder() as the conversion function:
PyUnicode_FSDecoder()
ParseTuple converter: decode bytes objects – obtained either directly or indirectly through the os.PathLike interface – to str 使用 PyUnicode_DecodeFSDefaultAndSize() ; str objects are output as-is. result 必须为 PyUnicodeObject * which must be released when it is no longer used.
Added in version 3.2.
Decode a string from the 文件系统编码和错误处理程序 .
If you need to decode a string from the current locale encoding, use PyUnicode_DecodeLocaleAndSize() .
3.6 版改变： The 文件系统错误处理程序 is now used.
Decode a null-terminated string from the 文件系统编码和错误处理程序 .
If the string length is known, use PyUnicode_DecodeFSDefaultAndSize() .
Encode a Unicode object to the 文件系统编码和错误处理程序 , and return bytes . Note that the resulting bytes object can contain null bytes.
If you need to encode a string to the current locale encoding, use PyUnicode_EncodeLocale() .
PyUnicode_EncodeLocale()
wchar_t support for platforms which support it:
Create a Unicode object from the wchar_t buffer wstr 为给定 size . Passing -1 作为 size indicates that the function must itself compute the length, using wcslen() 。返回 NULL 当故障时。
wcslen()
Copy the Unicode object contents into the wchar_t buffer wstr . 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.
当 wstr is NULL , instead return the size that would be required to store all of unicode including a terminating null.
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.
Convert the Unicode object to a wide character string. The output string always ends with a null character. If size 不是 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 和 wchar_t * string contains null characters a ValueError 被引发。
ValueError
Returns a buffer allocated by PyMem_New (使用 PyMem_Free() to free it) on success. On error, returns NULL and *size is undefined. Raises a MemoryError if memory allocation is failed.
PyMem_New
PyMem_Free()
3.7 版改变： 引发 ValueError if size is NULL 和 wchar_t * string contains null characters.
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.
str()
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 文件系统编码和错误处理程序 internally.
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 被引发)。
The codecs all use a similar interface. Only deviations from the following generic ones are documented for simplicity.
These are the generic codec APIs:
Create a Unicode object by decoding size bytes of the encoded string str . 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.
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.
encode()
These are the UTF-8 codec APIs:
Create a Unicode object by decoding size bytes of the UTF-8 encoded string str 。返回 NULL if an exception was raised by the codec.
若 consumed is NULL , behave like PyUnicode_DecodeUTF8() 。若 consumed 不是 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 .
PyUnicode_DecodeUTF8()
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.
Return a pointer to the UTF-8 encoding of the Unicode object, and store the size of the encoded representation (in bytes) in size 。 size 自变量可以是 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 是存储。
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.
3.7 版改变： The return type is now const char * rather of char * .
const char *
char *
3.10 版改变： This function is a part of the limited API .
As PyUnicode_AsUTF8AndSize() , but does not store the size.
PyUnicode_AsUTF8AndSize()
These are the UTF-32 codec APIs:
解码 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”.
若 byteorder 为非 NULL , the decoder starts decoding using the given byte order:
*byteorder == -1: little endian *byteorder == 0: native order *byteorder == 1: big endian
若 *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.
*byteorder
After completion, *byteorder is set to the current byte order at the end of input data.
若 byteorder is NULL , the codec starts in native order mode.
返回 NULL if an exception was raised by the codec.
若 consumed is NULL , behave like PyUnicode_DecodeUTF32() 。若 consumed 不是 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 .
PyUnicode_DecodeUTF32()
PyUnicode_DecodeUTF32Stateful()
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.
These are the UTF-16 codec APIs:
解码 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”.
若 *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 或 \ufffe character).
\ufeff
\ufffe
若 consumed is NULL , behave like PyUnicode_DecodeUTF16() 。若 consumed 不是 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 .
PyUnicode_DecodeUTF16()
PyUnicode_DecodeUTF16Stateful()
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.
These are the UTF-7 codec APIs:
Create a Unicode object by decoding size bytes of the UTF-7 encoded string str 。返回 NULL if an exception was raised by the codec.
若 consumed is NULL , behave like PyUnicode_DecodeUTF7() 。若 consumed 不是 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 .
PyUnicode_DecodeUTF7()
These are the “Unicode Escape” codec APIs:
Create a Unicode object by decoding size bytes of the Unicode-Escape encoded string str 。返回 NULL if an exception was raised by the codec.
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.
These are the “Raw Unicode Escape” codec APIs:
Create a Unicode object by decoding size bytes of the Raw-Unicode-Escape encoded string str 。返回 NULL if an exception was raised by the codec.
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.
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.
Create a Unicode object by decoding size bytes of the Latin-1 encoded string str 。返回 NULL if an exception was raised by the codec.
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.
These are the ASCII codec APIs. Only 7-bit ASCII data is accepted. All other codes generate errors.
Create a Unicode object by decoding size bytes of the ASCII encoded string str 。返回 NULL if an exception was raised by the codec.
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.
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.
encodings
__getitem__()
These are the mapping codec APIs:
Create a Unicode object by decoding size bytes of the encoded string str 使用给定 映射 object. Return NULL if an exception was raised by the codec.
若 映射 is NULL , Latin-1 decoding will be applied. Else 映射 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.
None
LookupError
0xFFFE
'\ufffe'
Encode a Unicode object using the given 映射 object and return the result as a bytes object. Error handling is “strict”. Return NULL if an exception was raised by the codec.
The 映射 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.
The following codec API is special in that maps Unicode to Unicode.
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.
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.
Create a Unicode object by decoding size bytes of the MBCS encoded string str 。返回 NULL if an exception was raised by the codec.
若 consumed is NULL , behave like PyUnicode_DecodeMBCS() 。若 consumed 不是 NULL , PyUnicode_DecodeMBCSStateful() will not decode trailing lead byte and the number of bytes that have been decoded will be stored in consumed .
PyUnicode_DecodeMBCS()
PyUnicode_DecodeMBCSStateful()
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.
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.
CP_ACP
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.
Concat two strings giving a new Unicode string.
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.
Split a Unicode string at line breaks, returning a list of Unicode strings. CRLF is considered to be one line break. If keepends is 0 , the Line break characters are not included in the resulting strings.
Join a sequence of strings using the given separator and return the resulting Unicode string.
返回 1 if substr 匹配 unicode[start:end] at the given tail end ( direction == -1 means to do a prefix match, direction == 1 a suffix match), 0 otherwise. Return -1 若出现错误。
unicode[start:end]
Return the first position of substr in unicode[start:end] 使用给定 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.
-2
Return the first position of the character ch in unicode[start:end] 使用给定 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.
3.7 版改变： start and end are now adjusted to behave like unicode[start:end] .
Return the number of non-overlapping occurrences of substr in unicode[start:end] 。返回 -1 若出现错误。
Replace at most maxcount occurrences of substr in unicode with replstr and return the resulting Unicode object. maxcount == -1 means replace all occurrences.
Compare two strings and return -1 , 0 , 1 for less than, equal, and greater than, respectively.
此函数返回 -1 upon failure, so one should call PyErr_Occurred() to check for errors.
PyErr_Occurred()
Compare a Unicode object, unicode ，采用 string 并返回 -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.
Rich compare two Unicode strings and return one of the following:
NULL in case an exception was raised
Py_True or Py_False for successful comparisons
Py_True
Py_False
Py_NotImplemented in case the type combination is unknown
Py_NotImplemented
可能的值对于 op are Py_GT , Py_GE , Py_EQ , Py_NE , Py_LT ，和 Py_LE .
Py_GT
Py_GE
Py_EQ
Py_NE
Py_LT
Py_LE
Return a new string object from format and args ; this is analogous to format % args .
format % args
校验是否 substr is contained in unicode and return true or false accordingly.
substr has to coerce to a one element Unicode string. -1 is returned if there was an error.
Intern the argument * p_unicode 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 * p_unicode , it sets * p_unicode to it (releasing the reference to the old string object and creating a new 强引用 to the interned string object), otherwise it leaves * p_unicode alone and interns it (creating a new 强引用 ). (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.)
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.
PyUnicode_FromString()
PyUnicode_InternInPlace()
字节数组对象
元组对象
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