[Python-checkins] cpython: Issue #21708: Deprecated dbm.dumb behavior that differs from common dbm
serhiy.storchaka
python-checkins at python.org
Wed Jul 6 05:22:30 EDT 2016
https://hg.python.org/cpython/rev/62da75b29b29
changeset: 102260:62da75b29b29
user: Serhiy Storchaka <storchaka at gmail.com>
date: Wed Jul 06 12:21:58 2016 +0300
summary:
Issue #21708: Deprecated dbm.dumb behavior that differs from common dbm
behavior: creating a database in 'r' and 'w' modes and modifying a database
in 'r' mode.
files:
Doc/library/dbm.rst | 4 ++++
Doc/whatsnew/3.6.rst | 5 +++++
Lib/dbm/dumb.py | 18 ++++++++++++++++++
Lib/test/test_dbm_dumb.py | 27 ++++++++++++++++++++++++++-
Misc/NEWS | 4 ++++
5 files changed, 57 insertions(+), 1 deletions(-)
diff --git a/Doc/library/dbm.rst b/Doc/library/dbm.rst
--- a/Doc/library/dbm.rst
+++ b/Doc/library/dbm.rst
@@ -351,6 +351,10 @@
:func:`.open` always creates a new database when the flag has the value
``'n'``.
+ .. deprecated-removed:: 3.6 3.8
+ Creating database in ``'r'`` and ``'w'`` modes. Modifying database in
+ ``'r'`` mode.
+
In addition to the methods provided by the
:class:`collections.abc.MutableMapping` class, :class:`dumbdbm` objects
provide the following methods:
diff --git a/Doc/whatsnew/3.6.rst b/Doc/whatsnew/3.6.rst
--- a/Doc/whatsnew/3.6.rst
+++ b/Doc/whatsnew/3.6.rst
@@ -604,6 +604,11 @@
``__package__`` are not defined now raises an :exc:`ImportWarning`.
(Contributed by Rose Ames in :issue:`25791`.)
+* Unlike to other :mod:`dbm` implementations, the :mod:`dbm.dumb` module
+ creates database in ``'r'`` and ``'w'`` modes if it doesn't exist and
+ allows modifying database in ``'r'`` mode. This behavior is now deprecated
+ and will be removed in 3.8.
+ (Contributed by Serhiy Storchaka in :issue:`21708`.)
Deprecated Python behavior
--------------------------
diff --git a/Lib/dbm/dumb.py b/Lib/dbm/dumb.py
--- a/Lib/dbm/dumb.py
+++ b/Lib/dbm/dumb.py
@@ -47,6 +47,7 @@
def __init__(self, filebasename, mode, flag='c'):
self._mode = mode
+ self._readonly = (flag == 'r')
# The directory file is a text file. Each line looks like
# "%r, (%d, %d)\n" % (key, pos, siz)
@@ -80,6 +81,11 @@
try:
f = _io.open(self._datfile, 'r', encoding="Latin-1")
except OSError:
+ if flag not in ('c', 'n'):
+ import warnings
+ warnings.warn("The database file is missing, the "
+ "semantics of the 'c' flag will be used.",
+ DeprecationWarning, stacklevel=4)
with _io.open(self._datfile, 'w', encoding="Latin-1") as f:
self._chmod(self._datfile)
else:
@@ -178,6 +184,10 @@
f.write("%r, %r\n" % (key.decode("Latin-1"), pos_and_siz_pair))
def __setitem__(self, key, val):
+ if self._readonly:
+ import warnings
+ warnings.warn('The database is opened for reading only',
+ DeprecationWarning, stacklevel=2)
if isinstance(key, str):
key = key.encode('utf-8')
elif not isinstance(key, (bytes, bytearray)):
@@ -212,6 +222,10 @@
# (so that _commit() never gets called).
def __delitem__(self, key):
+ if self._readonly:
+ import warnings
+ warnings.warn('The database is opened for reading only',
+ DeprecationWarning, stacklevel=2)
if isinstance(key, str):
key = key.encode('utf-8')
self._verify_open()
@@ -300,4 +314,8 @@
else:
# Turn off any bits that are set in the umask
mode = mode & (~um)
+ if flag not in ('r', 'w', 'c', 'n'):
+ import warnings
+ warnings.warn("Flag must be one of 'r', 'w', 'c', or 'n'",
+ DeprecationWarning, stacklevel=2)
return _Database(file, mode, flag=flag)
diff --git a/Lib/test/test_dbm_dumb.py b/Lib/test/test_dbm_dumb.py
--- a/Lib/test/test_dbm_dumb.py
+++ b/Lib/test/test_dbm_dumb.py
@@ -6,6 +6,7 @@
import operator
import os
import unittest
+import warnings
import dbm.dumb as dumbdbm
from test import support
from functools import partial
@@ -78,6 +79,12 @@
self.init_db()
f = dumbdbm.open(_fname, 'r')
self.read_helper(f)
+ with self.assertWarnsRegex(DeprecationWarning,
+ 'The database is opened for reading only'):
+ f[b'g'] = b'x'
+ with self.assertWarnsRegex(DeprecationWarning,
+ 'The database is opened for reading only'):
+ del f[b'a']
f.close()
def test_dumbdbm_keys(self):
@@ -148,7 +155,7 @@
self.assertEqual(self._dict[key], f[key])
def init_db(self):
- f = dumbdbm.open(_fname, 'w')
+ f = dumbdbm.open(_fname, 'n')
for k in self._dict:
f[k] = self._dict[k]
f.close()
@@ -234,6 +241,24 @@
pass
self.assertEqual(stdout.getvalue(), '')
+ def test_warn_on_ignored_flags(self):
+ for value in ('r', 'w'):
+ _delete_files()
+ with self.assertWarnsRegex(DeprecationWarning,
+ "The database file is missing, the "
+ "semantics of the 'c' flag will "
+ "be used."):
+ f = dumbdbm.open(_fname, value)
+ f.close()
+
+ def test_invalid_flag(self):
+ for flag in ('x', 'rf', None):
+ with self.assertWarnsRegex(DeprecationWarning,
+ "Flag must be one of "
+ "'r', 'w', 'c', or 'n'"):
+ f = dumbdbm.open(_fname, flag)
+ f.close()
+
def tearDown(self):
_delete_files()
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -24,6 +24,10 @@
Library
-------
+- Issue #21708: Deprecated dbm.dumb behavior that differs from common dbm
+ behavior: creating a database in 'r' and 'w' modes and modifying a database
+ in 'r' mode.
+
- Issue #26721: Change the socketserver.StreamRequestHandler.wfile attribute
to implement BufferedIOBase. In particular, the write() method no longer
does partial writes.
--
Repository URL: https://hg.python.org/cpython
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