Backport relevant part of issue 2021 fix (r60695): Support with statement properly in tempfile.NamedTemporaryFile
diff --git a/Lib/tempfile.py b/Lib/tempfile.py
index 2e8cd6d..045e230 100644
--- a/Lib/tempfile.py
+++ b/Lib/tempfile.py
@@ -378,17 +378,25 @@
self.close_called = False
def __getattr__(self, name):
+ # Attribute lookups are delegated to the underlying file
+ # and cached for non-numeric results
+ # (i.e. methods are cached, closed and friends are not)
file = self.__dict__['file']
a = getattr(file, name)
if type(a) != type(0):
setattr(self, name, a)
return a
+ # The underlying __enter__ method returns the wrong object
+ # (self.file) so override it to return the wrapper
+ def __enter__(self):
+ self.file.__enter__()
+ return self
+
# NT provides delete-on-close as a primitive, so we don't need
# the wrapper to do anything special. We still use it so that
# file.name is useful (i.e. not "(fdopen)") with NamedTemporaryFile.
if _os.name != 'nt':
-
# Cache the unlinker so we don't get spurious errors at
# shutdown when the module-level "os" is None'd out. Note
# that this must be referenced as self.unlink, because the
@@ -405,6 +413,14 @@
def __del__(self):
self.close()
+ # Need to trap __exit__ as well to ensure the file gets
+ # deleted when used in a with statement
+ def __exit__(self, exc, value, tb):
+ result = self.file.__exit__(exc, value, tb)
+ self.close()
+ return result
+
+
def NamedTemporaryFile(mode='w+b', bufsize=-1, suffix="",
prefix=template, dir=None):
"""Create and return a temporary file.
diff --git a/Lib/test/test_tempfile.py b/Lib/test/test_tempfile.py
index 2047a63..cd7ff4e 100644
--- a/Lib/test/test_tempfile.py
+++ b/Lib/test/test_tempfile.py
@@ -1,5 +1,5 @@
# tempfile.py unit tests.
-
+from __future__ import with_statement
import tempfile
import os
import sys
@@ -298,7 +298,7 @@
# On Windows a spawn* /path/ with embedded spaces shouldn't be quoted,
# but an arg with embedded spaces should be decorated with double
# quotes on each end
- if sys.platform in ('win32'):
+ if sys.platform in ('win32',):
decorated = '"%s"' % sys.executable
tester = '"%s"' % tester
else:
@@ -601,7 +601,6 @@
def test_multiple_close(self):
# A NamedTemporaryFile can be closed many times without error
-
f = tempfile.NamedTemporaryFile()
f.write('abc\n')
f.close()
@@ -611,6 +610,16 @@
except:
self.failOnException("close")
+ def test_context_manager(self):
+ # A NamedTemporaryFile can be used as a context manager
+ with tempfile.NamedTemporaryFile() as f:
+ self.failUnless(os.path.exists(f.name))
+ self.failIf(os.path.exists(f.name))
+ def use_closed():
+ with f:
+ pass
+ self.failUnlessRaises(ValueError, use_closed)
+
# How to test the mode and bufsize parameters?
test_classes.append(test_NamedTemporaryFile)
diff --git a/Misc/NEWS b/Misc/NEWS
index cf73bca..e9473dd 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -83,6 +83,9 @@
Library
-------
+- #2021: Allow tempfile.NamedTemporaryFile to be used in with statements
+ by correctly supporting the context management protocol.
+
- Fixed _ctypes.COMError so that it must be called with exactly three
arguments, instances now have the hresult, text, and details
instance variables.