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...ASCII characters? Arguments for ASCII only by default: Non-ASCII identifiers by default makes common practice/assumptions subtly/unknowingly wrong; rarely wrong is worse than obviously wrong. Better to raise a warning than to fail silently when encountering a probably unexpected situation. All of current usage is ASCII-only; the vast majority of future usage will be ASCII-only. It is the pockets of Unicode adoption that are parochial, not the ASCII advocates. Python should audit for ASCII-onl...
...ASCII (PyObject *o). This function converts any python object to a string using PyObject_Repr() and then hex-escapes all non-ASCII characters. PyObject_ASCII() generates the same string as PyObject_Repr() in Python 2. Add a new built-in function, ascii(). This function converts any python object to a string using repr() and then hex-escapes all non-ASCII characters. ascii() generates the same string as repr() in Python 2. Add a '%a' string format operator. '%a' converts any python object to...
...ASCII characters in Unicode literals. PEP 263 identified the problem that you can use only those Unicode characters in a Unicode literal which are also in Latin-1, and introduced a syntax for declaring the source encoding. If no source encoding was given, the default should be ASCII. For compatibility with Python 2.0 and 2.1, files were interpreted as Latin-1 for a transitional period. This transition ended with Python 2.5, which gives an error if non-ASCII characters are encountered and no sour...
...ASCII in string literals without declaring an encoding, the implementation will be introduced in two phases: Allow non-ASCII in string literals and comments, by internally treating a missing encoding declaration as a declaration of "iso-8859-1". This will cause arbitrary byte strings to correctly round-trip between step 2 and step 5 of the processing, and provide compatibility with Python 2.2 for Unicode literals that contain non-ASCII bytes. A warning will be issued if non-ASCII bytes are foun...
...ascii') This PEP proposes that an ascii method be added to bytes and bytearray to handle this use-case: >>> bytes.ascii(123) b'123' Note that bytes.ascii() would handle simple ascii-encodable text correctly, unlike the ascii() built-in: >>> ascii("hello").encode('ascii') b"'hello'" Addition of "getbyte" method to retrieve a single byte This PEP proposes that bytes and bytearray gain the method getbyte which will always return bytes: >>> b'abc'.getbyte(0) b'a' ...
...ASCII strings (i.e. ASCII-encoded byte strings). With the proposed approach, ASCII-only Unicode strings will again use only one byte per character; while still allowing efficient indexing of strings containing non-BMP characters (as strings containing them will use 4 bytes per character). One problem with the approach is support for existing applications (e.g. extension modules). For compatibility, redundant representations may be computed. Applications are encouraged to phase out reliance on a ...
...ASCII-only Considerations ASCII is a subset of Unicode, consisting of the most common symbols, numbers, Latin letters and control characters. While issues with the ASCII character set are generally well understood, the're presented here to help better understanding of the non-ASCII cases. Confusables and Typos Some characters look alike. Before the age of computers, many mechanical typewriters lacked the keys for the digits 0 and 1: users typed O (capital o) and l (lowercase L) instead. Human r...
...ASCII encoding will be an attractive nuisance and lead us back to the problems of the Python 2 str/unicode text model As was seen during the discussion, bytes and bytearray are also used for mixed binary data and ASCII-compatible segments: file formats such as dbf and pdf, network protocols such as ftp and email, etc. bytes and bytearray already have several methods which assume an ASCII compatible encoding. upper(), isalpha(), and expandtabs() to name just a few. %-interpolation, with its ve...
...ASCII strings and arbitrary binary data. Motivation Existing spellings of an ASCII string in Python 3000 include: bytes('Hello world', 'ascii') 'Hello world'.encode('ascii') The proposed syntax is: b'Hello world' Existing spellings of an 8-bit binary sequence in Python 3000 include: bytes([0x7f, 0x45, 0x4c, 0x46, 0x01, 0x01, 0x01, 0x00]) bytes('\x7fELF\x01\x01\x01\0', 'latin-1') '7f454c4601010100'.decode('hex') The proposed syntax is: b'\x7f\x45\x4c\x46\x01\x01\x01\x00' b'\x7fELF\x01\x0...
...ASCII? A: The system default encoding for Python is ASCII. It seems least confusing to use that default. Also, in Py3k, using Latin-1 as the default might not be what users expect. For example, they might prefer a Unicode encoding. Any default will not always work as expected. At least ASCII will complain loudly if you try to encode non-ASCII data. Copyright This document has been placed in the public domain. Source: https://github.com/python/peps/blob/master/pep-0358.txt
...ASCII and UTF-8, but will nevertheless often tolerate processing as surrogate escaped data - the points where GB 18030 reuses ASCII byte values in an incompatible way are likely to be invalid in UTF-8, and will therefore be escaped and opaque to string processing operations that split on or search for the relevant ASCII code points. Operations that don't involve splitting on or searching for particular ASCII or Unicode code point values are almost certain to work correctly. Similarly, Shift-JIS ...
...ASCII character (e.g. emoji, author names, copyright symbols, and the like) in their UTF-8-encoded README.md file. Of the 4000 most downloaded packages from PyPI, 489 use non-ASCII characters in their README, and 82 fail to install from source on non-UTF-8 locales due to not specifying an encoding for a non-ASCII file. [1] Another example is logging.basicConfig(filename="log.txt"). Some users might expect it to use UTF-8 by default, but the locale encoding is actually what is used. [2] Even Pyth...
...ASCII and non-ASCII character data and to also hold sequences of raw bytes which have no reasonable interpretation as displayable character sequences. This overlap hasn't been a big problem in the past, but as Python moves closer to requiring source code to be properly encoded, the use of strings to represent raw byte sequences will be more problematic. In addition, as Python's Unicode support has improved, it's easier to consider strings as ASCII-encoded Unicode objects. Proposed Implementa...
...ASCII string): >>> print(['ัะตัั']) ['\xd4\xc5\xd3\xd4'] One of the motivations for PEP 3138 is that neither repr nor str will allow the sensible printing of dicts whose keys are non-ASCII text strings. Now that Unicode identifiers are allowed, it includes Python's own attribute dicts. This also includes JSON serialization (and caused some hoops for the json lib). PEP 3138 proposes to fix this by breaking the "repr is safe ASCII" invariant, and changing the way repr (which is used fo...
...ASCII names and opaque "textual" values using a varying and/or sometimes ill-defined encoding. Moreover, those headers can be followed by a binary body... which can be chunked and decorated with ASCII headers and trailers! While there are reasonably efficient ways to accumulate binary data (such as using a bytearray object, the bytes.join method or even io.BytesIO), none of them leads to the kind of readable and intuitive code that is produced by a %-formatted or {}-formatted template and a for...
...ASCII str / bytes hash collision Since the implementation of PEP 393, bytes and ASCII text have the same memory layout. Because of this the new hashing API will keep the invariant: hash("ascii string") == hash(b"ascii string") for ASCII string and ASCII bytes. Equal hash values result in a hash collision and therefore cause a minor speed penalty for dicts and sets with mixed keys. The cause of the collision could be removed by e.g. subtracting 2 from the hash value of bytes. -2 because hash(b"...
...ASCII, module names must be encoded to form the PyInit hook name. For ASCII module names, the import hook is named PyInit_<modulename>, where <modulename> is the name of the module. For module names containing non-ASCII characters, the import hook is named PyInitU_<encodedname>, where the name is encoded using CPython's "punycode" encoding (Punycode with a lowercase suffix), with hyphens ("-") replaced by underscores ("_"). In Python: def export_hook_name(name): try: ...
...ASCII compatible encoding is required to maintain compatibility with code that bypasses the TextIOWrapper and directly writes ASCII bytes to the standard streams (for example, Twisted's process_stdinreader.py). Code that assumes a particular encoding for the standard streams other than ASCII will likely break. Add _PyOS_WindowsConsoleReadline To allow Unicode entry at the interactive prompt, a new readline hook is required. The existing PyOS_StdioReadline function will delegate to the new _PyO...
...ASCII encoding from the POSIX locale, aka the "C" locale, but are unable change the locale for various reasons. This encoding is very limited in term of Unicode support: any non-ASCII character is likely to cause trouble. It isn't always easy to get an accurate locale. Locales don't get the exact same name on different Linux distributions, FreeBSD, macOS, etc. And some locales, like the recent C.UTF-8 locale, are only supported by a few platforms. The current locale can even vary on the same ...
...ASCII then everything is fine and no such notice is needed, but if you include Latin-1 characters not defined in ASCII, it may well be worthwhile including a hint since people in other countries will want to be able to read your source strings too. Unicode Type Object Unicode objects should have the type UnicodeType with type name 'unicode', made available through the standard types module. Unicode Output Unicode objects have a method .encode([encoding=<default encoding>]) which return...