Aug 30, 2017 · Aug 30, 2017 · Sep 20, 2017 · Sep 30, 2017 · Sep 30, 2017 · Sep 9, 2018
diff --git a/Lib/tempfile.py b/Lib/tempfile.py
    def __iter__(self):
        return self._file.__iter__()

    def __del__(self):
        return self._file.__del__()

    def close(self):
        self._file.close()

    def read(self, *args):
        return self._file.read(*args)

    def readable(self):
        return self._file.readable()

    def readinto(self, b):
        return self._file.readinto(b)

    def readline(self, *args):
        return self._file.readline(*args)

    def seek(self, *args):
        self._file.seek(*args)

    def seekable(self):
        return self._file.seekable()

    @property
    def softspace(self):
        return self._file.softspace
        self._check(file)
        return rv

    def writable(self):
        return self._file.writable()

    def writelines(self, iterable):
        file = self._file
        rv = file.writelines(iterable)
diff --git a/Lib/test/test_tempfile.py b/Lib/test/test_tempfile.py
        f = self.do_create(max_size=100, pre="a", suf=".txt")
        self.assertFalse(f._rolled)

    def test_iobase_abstract(self):
        # SpooledTemporaryFile should implement the IOBase abstract
        iobase_abstract = (
            'close',
            'closed',
            'fileno',
            'flush',
            'isatty',
            'read',
            'readable',
            'readinto',
            'readline',
            'readlines',
            'seek',
            'seekable',
            'tell',
            'truncate',
            'write',
            'writable',
            'writelines',
            '__del__',
        )
        f = self.do_create()
        for attribute in iobase_abstract:
            self.assertTrue(
                hasattr(f, attribute),
                '{} attribute missing'.format(attribute)
            )

    def test_del_on_close(self):
        # A SpooledTemporaryFile is deleted when closed
        dir = tempfile.mkdtemp()
diff --git a/Misc/NEWS.d/next/Library/2017-08-30-23-14-17.bpo-26175.GOaj9y.rst b/Misc/NEWS.d/next/Library/2017-08-30-23-14-17.bpo-26175.GOaj9y.rst
 Fully implement `io.IOBase` abstract for `tempfile.SpooledTemporaryFile`.
 Patch by Gary Fernie
Original file line number	Diff line number	Diff line change
Expand Up		@@ -685,6 +685,9 @@ def __exit__(self, exc, value, tb):
		def __iter__(self):
		return self._file.__iter__()

		def __del__(self):
Copy link ppperyJun 6, 2018• edited Loading Choose a reason for hiding this comment The reason will be displayed to describe this comment to others.Learn more. This shouldn't be added: deleting the SpooledTemporaryFile will null out the reference to the underline file, and therefor call its `__del__` Copy link Member vadmiumJun 9, 2018• edited Loading Choose a reason for hiding this comment The reason will be displayed to describe this comment to others.Learn more. I think if you inherit the default`IOBase.__del__` implementation, it will callclose and defeat any ResourceWarning that might otherwise be emitted. Perhaps it is better to make`__del__` do nothing,~~or set it to`object.__del__`~~. [Seems that last option doesn’t exist.] Copy link ContributorAuthor GFernieSep 9, 2018 Choose a reason for hiding this comment The reason will be displayed to describe this comment to others.Learn more. I agree: the underlying file should not be explicitly deleted as this is not expected behaviour. I can imagine a situation where someone is deliberately holding a reference to the underlying file and they would not expect/want it to be closed until their own reference has fallen out of scope. I've changed the method to do nothing and added a docstring to reflect this. Thanks for your feedback Copy link Member pitrouOct 22, 2018 Choose a reason for hiding this comment The reason will be displayed to describe this comment to others.Learn more. I agree: the underlying file should not be explicitly deleted as this is not expected behaviour The doc says: """This function operates exactly as TemporaryFile() does, except [irrelevant differences].""" And then, about TemporaryFile: """On completion of the context or destruction of the file object the temporary file will be removed from the filesystem.""" So it seems the underlying fileshould be deleted when the file object disappears. Copy link coleiferMar 23, 2019 Choose a reason for hiding this comment The reason will be displayed to describe this comment to others.Learn more. The point is that`IOBase` implements a`__del__` which has some side-effects. Those side effects are not desirable here. Any underlying buffers being wrapped, e.g. the`TemporaryFile` or the`BytesIO`, will be gc'd and handled as they should. I think this implementation is correct.
		return self._file.__del__()
Copy link Member pitrouNov 23, 2019 Choose a reason for hiding this comment The reason will be displayed to describe this comment to others.Learn more. Hmm, calling the`__del__` method directly like that is not correct.`__del__` is only to be called when all external references are gone. Instead I would suggest something like the following: def__del__(self):ifnotself.closed:importwarningswarnings.warn('unclosed file %r'% (self,),ResourceWarning,stacklevel=2,source=self)self.close() (this is adapted from`FileIO.__del__` in`Lib/pyio.py`)

		def close(self):
		self._file.close()

Expand DownExpand Up		@@ -737,6 +740,12 @@ def newlines(self):
		def read(self, *args):
		return self._file.read(*args)

		def readable(self):
		return self._file.readable()

		def readinto(self, b):
		return self._file.readinto(b)

		def readline(self, *args):
		return self._file.readline(*args)

Expand All		@@ -746,6 +755,9 @@ def readlines(self, *args):
		def seek(self, *args):
		self._file.seek(*args)

		def seekable(self):
		return self._file.seekable()

		@property
		def softspace(self):
		return self._file.softspace
Expand All		@@ -767,6 +779,9 @@ def write(self, s):
		self._check(file)
		return rv

		def writable(self):
		return self._file.writable()

		def writelines(self, iterable):
		file = self._file
		rv = file.writelines(iterable)
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -982,6 +982,35 @@ def test_basic(self):
		f = self.do_create(max_size=100, pre="a", suf=".txt")
		self.assertFalse(f._rolled)

		def test_iobase_abstract(self):
		# SpooledTemporaryFile should implement the IOBase abstract
		iobase_abstract = (
		'close',
		'closed',
		'fileno',
		'flush',
		'isatty',
		'read',
		'readable',
		'readinto',
		'readline',
		'readlines',
		'seek',
		'seekable',
		'tell',
		'truncate',
		'write',
		'writable',
		'writelines',
		'__del__',
		)
		f = self.do_create()
		for attribute in iobase_abstract:
		self.assertTrue(
		hasattr(f, attribute),
		'{} attribute missing'.format(attribute)
		)
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		def test_del_on_close(self):
		# A SpooledTemporaryFile is deleted when closed
		dir = tempfile.mkdtemp()
Expand Down
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,2 @@
		Fully implement `io.IOBase` abstract for `tempfile.SpooledTemporaryFile`.
		Patch by Gary Fernie