If buffering=1 is specified for open() in binary mode, it is silently
treated as buffering=-1 (i.e., the default buffer size).
Coupled with the fact that line buffering is always supported in Python 2,
such behavior caused several issues (e.g., bpo-10344, bpo-21332).
Warn that line buffering is not supported if open() is called with
binary mode and buffering=1.
* Maintain a list of BufferedWriter objects. Flush them on exit.
In Python 3, the buffer and the underlying file object are separate
and so the order in which objects are finalized matters. This is
unlike Python 2 where the file and buffer were a single object and
finalization was done for both at the same time. In Python 3, if
the file is finalized and closed before the buffer then the data in
the buffer is lost.
This change adds a doubly linked list of open file buffers. An atexit
hook ensures they are flushed before proceeding with interpreter
shutdown. This is addition does not remove the need to properly close
files as there are other reasons why buffered data could get lost during
finalization.
Initial patch by Armin Rigo.
* Use weakref.WeakSet instead of WeakKeyDictionary.
* Simplify buffered double-linked list types.
* In _flush_all_writers(), suppress errors from flush().
* Remove NEWS entry, use blurb.
* Take more care when flushing file buffers from atexit.
The previous implementation was not careful enough to avoid
causing issues in multi-threaded cases. Check for buf->ok
and buf->finalizing before actually doing the flush. Also,
increase the refcnt to ensure the object does not disappear.
* Maintain a list of BufferedWriter objects. Flush them on exit.
In Python 3, the buffer and the underlying file object are separate
and so the order in which objects are finalized matters. This is
unlike Python 2 where the file and buffer were a single object and
finalization was done for both at the same time. In Python 3, if
the file is finalized and closed before the buffer then the data in
the buffer is lost.
This change adds a doubly linked list of open file buffers. An atexit
hook ensures they are flushed before proceeding with interpreter
shutdown. This is addition does not remove the need to properly close
files as there are other reasons why buffered data could get lost during
finalization.
Initial patch by Armin Rigo.
* Use weakref.WeakSet instead of WeakKeyDictionary.
* Simplify buffered double-linked list types.
* In _flush_all_writers(), suppress errors from flush().
* Remove NEWS entry, use blurb.
This matches the usage of ZipFile and BufferedWriter. This still requires
return values to be bytes() objects.
Also document and test that the write() methods should only access their
argument before they return.
Issue #26604:
* Add a new optional source parameter to _warnings.warn() and warnings.warn()
* Modify asyncore, asyncio and _pyio modules to set the source parameter when
logging a ResourceWarning warning
This changes the main documentation, doc strings, source code comments, and a
couple error messages in the test suite. In some cases the word was removed
or edited some other way to fix the grammar.
Serhiy Storchaka
Alexey Izbyshev
Raymond Hettinger
Zackery Spytz
INADA Naoki
Antoine Pitrou
benfogle
Neil Schemenauer
Oren Milman
Jim Fasarakis-Hilliard
Martin Panter
Ethan Furman
Victor Stinner
Robert Collins
Antoine Pitrou
Benjamin Peterson
Charles-François Natali
Nick Coghlan