WhatsNew–Python3.5

Important

This file is used by maintainers to track implementation of core functionality from Python 3 into IronPython.

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What's New In Python 3.5

https://docs.python.org/3/whatsnew/3.5.html

New Features

• PEP 492: Coroutines with async and await syntax
• PEP 465: A dedicated infix operator for matrix multiplication
• PEP 448: Additional Unpacking Generalizations
• PEP 461: percent formatting support for bytes and bytearray
• PEP 484: Type Hints
• PEP 471: os.scandir() function – a better and faster directory iterator
• PEP 475: Retry system calls failing with EINTR
• PEP 479: Change StopIteration handling inside generators
• PEP 485: A function for testing approximate equality
• PEP 486: Make the Python Launcher aware of virtual environments
• PEP 488: Elimination of PYO files
• PEP 489: Multi-phase extension module initialization

Other Language Changes

• Added the "namereplace" error handlers. The "backslashreplace" error handlers now work with decoding and translating.
• The -b option now affects comparisons of bytes with int.
• New Kazakh kz1048 and Tajik koi8_t codecs.
• Property docstrings are now writable. This is especially useful for collections.namedtuple() docstrings.
• Circular imports involving relative imports are now supported.

New Modules

• typing
• zipapp

Improved Modules

• argparse
• asyncio
• bz2
• cgi
• cmath
• code
• collections
• collections.abc
• compileall
• concurrent.futures
• configparser
• contextlib
• csv
• curses
• dbm
• difflib
• distutils
• doctest
• email
• enum
• faulthandler
• functools
• glob
• gzip
• heapq
• http
• http.client
• idlelib and IDLE
• imaplib
• imghdr
• importlib
• inspect
• io
• ipaddress
• json
• linecache
• locale
• logging
• lzma
• math
• multiprocessing
• operator
• os
• pathlib
• pickle
• poplib
• re
• readline
• selectors
• shutil
• signal
• smtpd
• smtplib
• sndhdr
• socket
• ssl
• sqlite3
• subprocess
• sys
• sysconfig
• tarfile
• threading
• time
• timeit
• tkinter
• traceback
• types
• unicodedata
• unittest
• unittest.mock
• urllib
• wsgiref
• xmlrpc
• xml.sax
• zipfile

Other module-level changes

• Many functions in the mmap, ossaudiodev, socket, ssl, and codecs modules now accept writable bytes-like objects.

Deprecated

• New Keywords: async and await are not recommended to be used as variable, class, function or module names. Introduced by PEP 492 in Python 3.5, they will become proper keywords in Python 3.7.
• Deprecated Python Behavior: Raising the StopIteration exception inside a generator will now generate a silent PendingDeprecationWarning, which will become a non-silent deprecation warning in Python 3.6 and will trigger a RuntimeError in Python 3.7. See PEP 479: Change StopIteration handling inside generators for details.

Deprecated Python modules, functions and methods

• The formatter module has now graduated to full deprecation and is still slated for removal in Python 3.6.
• The asyncio.async() function is deprecated in favor of ensure_future().
• The smtpd module has in the past always decoded the DATA portion of email messages using the utf-8 codec. This can now be controlled by the new decode__data keyword to SMTPServer. The default value is True, but this default is deprecated. Specify the decode__data keyword with an appropriate value to avoid the deprecation warning.
• Directly assigning values to the key, value and coded_value of http.cookies.Morsel objects is deprecated. Use the set() method instead. In addition, the undocumented LegalChars parameter of set() is deprecated, and is now ignored.
• Passing a format string as keyword argument format__string to the format() method of the string.Formatter class has been deprecated.
• The platform.dist() and platform.linux_distribution() functions are now deprecated. Linux distributions use too many different ways of describing themselves, so the functionality is left to a package.
• The previously undocumented from_function and from_builtin methods of inspect.Signature are deprecated. Use the new Signature.from_callable() method instead.
• The inspect.getargspec() function is deprecated and scheduled to be removed in Python 3.6.
• The inspect getfullargspec(), getcallargs(), and formatargspec() functions are deprecated in favor of the inspect.signature() API.
• getargvalues() and formatargvalues() functions were inadvertently marked as deprecated with the release of Python 3.5.0.
• Use of re.LOCALE flag with str patterns or re.ASCII is now deprecated.
• Use of unrecognized special sequences consisting of '\' and an ASCII letter in regular expression patterns and replacement patterns now raises a deprecation warning and will be forbidden in Python 3.6.
• The undocumented and unofficial use__load__tests default argument of the unittest.TestLoader.loadTestsFromModule() method now is deprecated and ignored.

Removed

• The __version__ attribute has been dropped from the email package. The email code hasn’t been shipped separately from the stdlib for a long time, and the __version__ string was not updated in the last few releases.
• The internal Netrc class in the ftplib module was deprecated in 3.4, and has now been removed.
• The concept of .pyo files has been removed.
• The JoinableQueue class in the provisional asyncio module was deprecated in 3.4.4 and is now removed.