bpo-37111: Add 'encoding' and 'errors' parameters to logging.basicCon… (GH-14008)

Doc/howto/logging.rst

@@ -128,10 +128,18 @@ look at that next. Be sure to try the following in a newly-started Python
 interpreter, and don't just continue from the session described above::
 
    import logging
-   logging.basicConfig(filename='example.log',level=logging.DEBUG)
+   logging.basicConfig(filename='example.log', encoding='utf-8', level=logging.DEBUG)
    logging.debug('This message should go to the log file')
    logging.info('So should this')
    logging.warning('And this, too')
+   logging.error('And non-ASCII stuff, too, like Øresund and Malmö')
+
+.. versionchanged:: 3.9
+   The *encoding* argument was added. In earlier Python versions, or if not
+   specified, the encoding used is the default value used by :func:`open`. While
+   not shown in the above example, an *errors* argument can also now be passed,
+   which determines how encoding errors are handled. For available values and
+   the default, see the documentation for :func:`open`.
 
 And now if we open the file and look at what we have, we should find the log
 messages:
@@ -141,6 +149,7 @@ messages:
    DEBUG:root:This message should go to the log file
    INFO:root:So should this
    WARNING:root:And this, too
+   ERROR:root:And non-ASCII stuff, too, like Øresund and Malmö
 
 This example also shows how you can set the logging level which acts as the
 threshold for tracking. In this case, because we set the threshold to

Doc/library/logging.handlers.rst

@@ -89,18 +89,22 @@ sends logging output to a disk file.  It inherits the output functionality from
 :class:`StreamHandler`.
 
 
-.. class:: FileHandler(filename, mode='a', encoding=None, delay=False)
+.. class:: FileHandler(filename, mode='a', encoding=None, delay=False, errors=None)
 
    Returns a new instance of the :class:`FileHandler` class. The specified file is
    opened and used as the stream for logging. If *mode* is not specified,
    :const:`'a'` is used.  If *encoding* is not ``None``, it is used to open the file
    with that encoding.  If *delay* is true, then file opening is deferred until the
-   first call to :meth:`emit`. By default, the file grows indefinitely.
+   first call to :meth:`emit`. By default, the file grows indefinitely. If
+   *errors* is specified, it's used to determine how encoding errors are handled.
 
    .. versionchanged:: 3.6
       As well as string values, :class:`~pathlib.Path` objects are also accepted
       for the *filename* argument.
 
+   .. versionchanged:: 3.9
+      The *errors* parameter was added.
+
    .. method:: close()
 
       Closes the file.
@@ -168,18 +172,22 @@ exclusive locks - and so there is no need for such a handler. Furthermore,
 for this value.
 
 
-.. class:: WatchedFileHandler(filename, mode='a', encoding=None, delay=False)
+.. class:: WatchedFileHandler(filename, mode='a', encoding=None, delay=False, errors=None)
 
    Returns a new instance of the :class:`WatchedFileHandler` class. The specified
    file is opened and used as the stream for logging. If *mode* is not specified,
    :const:`'a'` is used.  If *encoding* is not ``None``, it is used to open the file
    with that encoding.  If *delay* is true, then file opening is deferred until the
-   first call to :meth:`emit`.  By default, the file grows indefinitely.
+   first call to :meth:`emit`.  By default, the file grows indefinitely. If
+   *errors* is provided, it determines how encoding errors are handled.
 
    .. versionchanged:: 3.6
       As well as string values, :class:`~pathlib.Path` objects are also accepted
       for the *filename* argument.
 
+   .. versionchanged:: 3.9
+      The *errors* parameter was added.
+
    .. method:: reopenIfNeeded()
 
       Checks to see if the file has changed.  If it has, the existing stream is
@@ -205,7 +213,7 @@ module, is the base class for the rotating file handlers,
 not need to instantiate this class, but it has attributes and methods you may
 need to override.
 
-.. class:: BaseRotatingHandler(filename, mode, encoding=None, delay=False)
+.. class:: BaseRotatingHandler(filename, mode, encoding=None, delay=False, errors=None)
 
    The parameters are as for :class:`FileHandler`. The attributes are:
 
@@ -284,13 +292,14 @@ The :class:`RotatingFileHandler` class, located in the :mod:`logging.handlers`
 module, supports rotation of disk log files.
 
 
-.. class:: RotatingFileHandler(filename, mode='a', maxBytes=0, backupCount=0, encoding=None, delay=False)
+.. class:: RotatingFileHandler(filename, mode='a', maxBytes=0, backupCount=0, encoding=None, delay=False, errors=None)
 
    Returns a new instance of the :class:`RotatingFileHandler` class. The specified
    file is opened and used as the stream for logging. If *mode* is not specified,
    ``'a'`` is used.  If *encoding* is not ``None``, it is used to open the file
    with that encoding.  If *delay* is true, then file opening is deferred until the
-   first call to :meth:`emit`.  By default, the file grows indefinitely.
+   first call to :meth:`emit`.  By default, the file grows indefinitely. If
+   *errors* is provided, it determines how encoding errors are handled.
 
    You can use the *maxBytes* and *backupCount* values to allow the file to
    :dfn:`rollover` at a predetermined size. When the size is about to be exceeded,
@@ -311,6 +320,9 @@ module, supports rotation of disk log files.
       As well as string values, :class:`~pathlib.Path` objects are also accepted
       for the *filename* argument.
 
+   .. versionchanged:: 3.9
+      The *errors* parameter was added.
+
    .. method:: doRollover()
 
       Does a rollover, as described above.
@@ -331,7 +343,7 @@ The :class:`TimedRotatingFileHandler` class, located in the
 timed intervals.
 
 
-.. class:: TimedRotatingFileHandler(filename, when='h', interval=1, backupCount=0, encoding=None, delay=False, utc=False, atTime=None)
+.. class:: TimedRotatingFileHandler(filename, when='h', interval=1, backupCount=0, encoding=None, delay=False, utc=False, atTime=None, errors=None)
 
    Returns a new instance of the :class:`TimedRotatingFileHandler` class. The
    specified file is opened and used as the stream for logging. On rotating it also
@@ -391,6 +403,9 @@ timed intervals.
    rollover, and subsequent rollovers would be calculated via the normal
    interval calculation.
 
+   If *errors* is specified, it's used to determine how encoding errors are
+   handled.
+
    .. note:: Calculation of the initial rollover time is done when the handler
       is initialised. Calculation of subsequent rollover times is done only
       when rollover occurs, and rollover occurs only when emitting output. If
@@ -411,6 +426,9 @@ timed intervals.
       As well as string values, :class:`~pathlib.Path` objects are also accepted
       for the *filename* argument.
 
+   .. versionchanged:: 3.9
+      The *errors* parameter was added.
+
    .. method:: doRollover()
 
       Does a rollover, as described above.

Doc/library/logging.rst

@@ -1196,6 +1196,21 @@ functions.
    |              | carrying out the configuration as specified |
    |              | by the other arguments.                     |
    +--------------+---------------------------------------------+
+   | *encoding*   | If this keyword argument is specified along |
+   |              | with *filename*, its value is used when the |
+   |              | FileHandler is created, and thus used when  |
+   |              | opening the output file.                    |
+   +--------------+---------------------------------------------+
+   | *errors*     | If this keyword argument is specified along |
+   |              | with *filename*, its value is used when the |
+   |              | FileHandler is created, and thus used when  |
+   |              | opening the output file. If not specified,  |
+   |              | the value 'backslashreplace' is used. Note  |
+   |              | that if ``None`` is specified, it will be   |
+   |              | passed as such to func:`open`, which means  |
+   |              | that it will be treated the same as passing |
+   |              | 'errors'.                                   |
+   +--------------+---------------------------------------------+
 
    .. versionchanged:: 3.2
       The *style* argument was added.
@@ -1209,6 +1224,9 @@ functions.
    .. versionchanged:: 3.8
       The *force* argument was added.
 
+   .. versionchanged:: 3.9
+      The *encoding* and *errors* arguments were added.
+
 .. function:: shutdown()
 
    Informs the logging system to perform an orderly shutdown by flushing and

Doc/tools/susp-ignored.csv

@@ -81,6 +81,7 @@ howto/ipaddress,,::,IPv6Address('2001:db8::ffff:ffff')
 howto/ipaddress,,:ffff,IPv6Address('2001:db8::ffff:ffff')
 howto/logging,,:And,"WARNING:And this, too"
 howto/logging,,:And,"WARNING:root:And this, too"
+howto/logging,,:And,"ERROR:root:And non-ASCII stuff, too, like "
 howto/logging,,:Doing,INFO:root:Doing something
 howto/logging,,:Finished,INFO:root:Finished
 howto/logging,,:logger,severity:logger name:message
@@ -90,6 +91,7 @@ howto/logging,,:root,DEBUG:root:This message should go to the log file
 howto/logging,,:root,INFO:root:Doing something
 howto/logging,,:root,INFO:root:Finished
 howto/logging,,:root,INFO:root:So should this
+howto/logging,,:root,"ERROR:root:And non-ASCII stuff, too, like "
 howto/logging,,:root,INFO:root:Started
 howto/logging,,:root,"WARNING:root:And this, too"
 howto/logging,,:root,WARNING:root:Look before you leap!

Lib/logging/__init__.py

@@ -1,4 +1,4 @@
-# Copyright 2001-2017 by Vinay Sajip. All Rights Reserved.
+# Copyright 2001-2019 by Vinay Sajip. All Rights Reserved.
 #
 # Permission to use, copy, modify, and distribute this software and its
 # documentation for any purpose and without fee is hereby granted,
@@ -18,7 +18,7 @@
 Logging package for Python. Based on PEP 282 and comments thereto in
 comp.lang.python.
 
-Copyright (C) 2001-2017 Vinay Sajip. All Rights Reserved.
+Copyright (C) 2001-2019 Vinay Sajip. All Rights Reserved.
 
 To use, simply 'import logging' and log away!
 """
@@ -1122,7 +1122,7 @@ class FileHandler(StreamHandler):
     """
     A handler class which writes formatted logging records to disk files.
     """
-    def __init__(self, filename, mode='a', encoding=None, delay=False):
+    def __init__(self, filename, mode='a', encoding=None, delay=False, errors=None):
         """
         Open the specified file and use it as the stream for logging.
         """
@@ -1133,6 +1133,7 @@ class FileHandler(StreamHandler):
         self.baseFilename = os.path.abspath(filename)
         self.mode = mode
         self.encoding = encoding
+        self.errors = errors
         self.delay = delay
         if delay:
             #We don't open the stream, but we still need to call the
@@ -1169,7 +1170,8 @@ class FileHandler(StreamHandler):
         Open the current base file with the (original) mode and encoding.
         Return the resulting stream.
         """
-        return open(self.baseFilename, self.mode, encoding=self.encoding)
+        return open(self.baseFilename, self.mode, encoding=self.encoding,
+                    errors=self.errors)
 
     def emit(self, record):
         """
@@ -1928,15 +1930,20 @@ def basicConfig(**kwargs):
               attached to the root logger are removed and closed, before
               carrying out the configuration as specified by the other
               arguments.
+    encoding  If specified together with a filename, this encoding is passed to
+              the created FileHandler, causing it to be used when the file is
+              opened.
+    errors    If specified together with a filename, this value is passed to the
+              created FileHandler, causing it to be used when the file is
+              opened in text mode. If not specified, the default value is
+              `backslashreplace`.
+
     Note that you could specify a stream created using open(filename, mode)
     rather than passing the filename and mode in. However, it should be
     remembered that StreamHandler does not close its stream (since it may be
     using sys.stdout or sys.stderr), whereas FileHandler closes its stream
     when the handler is closed.
 
-    .. versionchanged:: 3.8
-       Added the ``force`` parameter.
-
     .. versionchanged:: 3.2
        Added the ``style`` parameter.
 
@@ -1946,12 +1953,20 @@ def basicConfig(**kwargs):
        ``filename``/``filemode``, or ``filename``/``filemode`` specified
        together with ``stream``, or ``handlers`` specified together with
        ``stream``.
+
+    .. versionchanged:: 3.8
+       Added the ``force`` parameter.
+
+    .. versionchanged:: 3.9
+       Added the ``encoding`` and ``errors`` parameters.
     """
     # Add thread safety in case someone mistakenly calls
     # basicConfig() from multiple threads
     _acquireLock()
     try:
         force = kwargs.pop('force', False)
+        encoding = kwargs.pop('encoding', None)
+        errors = kwargs.pop('errors', 'backslashreplace')
         if force:
             for h in root.handlers[:]:
                 root.removeHandler(h)
@@ -1970,7 +1985,10 @@ def basicConfig(**kwargs):
                 filename = kwargs.pop("filename", None)
                 mode = kwargs.pop("filemode", 'a')
                 if filename:
-                    h = FileHandler(filename, mode)
+                    if 'b'in mode:
+                        errors = None
+                    h = FileHandler(filename, mode,
+                                    encoding=encoding, errors=errors)
                 else:
                     stream = kwargs.pop("stream", None)
                     h = StreamHandler(stream)

Lib/logging/handlers.py

@@ -48,13 +48,16 @@ class BaseRotatingHandler(logging.FileHandler):
     Not meant to be instantiated directly.  Instead, use RotatingFileHandler
     or TimedRotatingFileHandler.
     """
-    def __init__(self, filename, mode, encoding=None, delay=False):
+    def __init__(self, filename, mode, encoding=None, delay=False, errors=None):
         """
         Use the specified filename for streamed logging
         """
-        logging.FileHandler.__init__(self, filename, mode, encoding, delay)
+        logging.FileHandler.__init__(self, filename, mode=mode,
+                                     encoding=encoding, delay=delay,
+                                     errors=errors)
         self.mode = mode
         self.encoding = encoding
+        self.errors = errors
         self.namer = None
         self.rotator = None
 
@@ -117,7 +120,8 @@ class RotatingFileHandler(BaseRotatingHandler):
     Handler for logging to a set of files, which switches from one file
     to the next when the current file reaches a certain size.
     """
-    def __init__(self, filename, mode='a', maxBytes=0, backupCount=0, encoding=None, delay=False):
+    def __init__(self, filename, mode='a', maxBytes=0, backupCount=0,
+                 encoding=None, delay=False, errors=None):
         """
         Open the specified file and use it as the stream for logging.
 
@@ -145,7 +149,8 @@ class RotatingFileHandler(BaseRotatingHandler):
         # on each run.
         if maxBytes > 0:
             mode = 'a'
-        BaseRotatingHandler.__init__(self, filename, mode, encoding, delay)
+        BaseRotatingHandler.__init__(self, filename, mode, encoding=encoding,
+                                     delay=delay, errors=errors)
         self.maxBytes = maxBytes
         self.backupCount = backupCount
 
@@ -196,8 +201,11 @@ class TimedRotatingFileHandler(BaseRotatingHandler):
     If backupCount is > 0, when rollover is done, no more than backupCount
     files are kept - the oldest ones are deleted.
     """
-    def __init__(self, filename, when='h', interval=1, backupCount=0, encoding=None, delay=False, utc=False, atTime=None):
+    def __init__(self, filename, when='h', interval=1, backupCount=0,
-        BaseRotatingHandler.__init__(self, filename, 'a', encoding, delay)
+                 encoding=None, delay=False, utc=False, atTime=None,
+                 errors=None):
+        BaseRotatingHandler.__init__(self, filename, 'a', encoding=encoding,
+                                     delay=delay, errors=errors)
         self.when = when.upper()
         self.backupCount = backupCount
         self.utc = utc
@@ -431,8 +439,11 @@ class WatchedFileHandler(logging.FileHandler):
     This handler is based on a suggestion and patch by Chad J.
     Schroeder.
     """
-    def __init__(self, filename, mode='a', encoding=None, delay=False):
+    def __init__(self, filename, mode='a', encoding=None, delay=False,
-        logging.FileHandler.__init__(self, filename, mode, encoding, delay)
+                 errors=None):
+        logging.FileHandler.__init__(self, filename, mode=mode,
+                                     encoding=encoding, delay=delay,
+                                     errors=errors)
         self.dev, self.ino = -1, -1
         self._statstream()
 

Lib/test/test_logging.py

@@ -1,4 +1,4 @@
-# Copyright 2001-2017 by Vinay Sajip. All Rights Reserved.
+# Copyright 2001-2019 by Vinay Sajip. All Rights Reserved.
 #
 # Permission to use, copy, modify, and distribute this software and its
 # documentation for any purpose and without fee is hereby granted,
@@ -16,7 +16,7 @@
 
 """Test harness for the logging module. Run all tests.
 
-Copyright (C) 2001-2017 Vinay Sajip. All Rights Reserved.
+Copyright (C) 2001-2019 Vinay Sajip. All Rights Reserved.
 """
 
 import logging
@@ -4445,6 +4445,99 @@ class BasicConfigTest(unittest.TestCase):
         self.assertEqual(new_string_io.getvalue().strip(),
                          'WARNING:root:warn\nINFO:root:info')
 
+    def test_encoding(self):
+        try:
+            encoding = 'utf-8'
+            logging.basicConfig(filename='test.log', encoding=encoding,
+                                errors='strict',
+                                format='%(message)s', level=logging.DEBUG)
+
+            self.assertEqual(len(logging.root.handlers), 1)
+            handler = logging.root.handlers[0]
+            self.assertIsInstance(handler, logging.FileHandler)
+            self.assertEqual(handler.encoding, encoding)
+            logging.debug('The Øresund Bridge joins Copenhagen to Malmö')
+        finally:
+            handler.close()
+            with open('test.log', encoding='utf-8') as f:
+                data = f.read().strip()
+            os.remove('test.log')
+            self.assertEqual(data,
+                             'The Øresund Bridge joins Copenhagen to Malmö')
+
+    def test_encoding_errors(self):
+        try:
+            encoding = 'ascii'
+            logging.basicConfig(filename='test.log', encoding=encoding,
+                                errors='ignore',
+                                format='%(message)s', level=logging.DEBUG)
+
+            self.assertEqual(len(logging.root.handlers), 1)
+            handler = logging.root.handlers[0]
+            self.assertIsInstance(handler, logging.FileHandler)
+            self.assertEqual(handler.encoding, encoding)
+            logging.debug('The Øresund Bridge joins Copenhagen to Malmö')
+        finally:
+            handler.close()
+            with open('test.log', encoding='utf-8') as f:
+                data = f.read().strip()
+            os.remove('test.log')
+            self.assertEqual(data, 'The resund Bridge joins Copenhagen to Malm')
+
+    def test_encoding_errors_default(self):
+        try:
+            encoding = 'ascii'
+            logging.basicConfig(filename='test.log', encoding=encoding,
+                                format='%(message)s', level=logging.DEBUG)
+
+            self.assertEqual(len(logging.root.handlers), 1)
+            handler = logging.root.handlers[0]
+            self.assertIsInstance(handler, logging.FileHandler)
+            self.assertEqual(handler.encoding, encoding)
+            self.assertEqual(handler.errors, 'backslashreplace')
+            logging.debug('😂: ☃️: The Øresund Bridge joins Copenhagen to Malmö')
+        finally:
+            handler.close()
+            with open('test.log', encoding='utf-8') as f:
+                data = f.read().strip()
+            os.remove('test.log')
+            self.assertEqual(data, r'\U0001f602: \u2603\ufe0f: The \xd8resund '
+                                   r'Bridge joins Copenhagen to Malm\xf6')
+
+    def test_encoding_errors_none(self):
+        # Specifying None should behave as 'strict'
+        try:
+            encoding = 'ascii'
+            logging.basicConfig(filename='test.log', encoding=encoding,
+                                errors=None,
+                                format='%(message)s', level=logging.DEBUG)
+
+            self.assertEqual(len(logging.root.handlers), 1)
+            handler = logging.root.handlers[0]
+            self.assertIsInstance(handler, logging.FileHandler)
+            self.assertEqual(handler.encoding, encoding)
+            self.assertIsNone(handler.errors)
+
+            message = []
+
+            def dummy_handle_error(record):
+                _, v, _ = sys.exc_info()
+                message.append(str(v))
+
+            handler.handleError = dummy_handle_error
+            logging.debug('The Øresund Bridge joins Copenhagen to Malmö')
+            self.assertTrue(message)
+            self.assertIn("'ascii' codec can't encode "
+                          "character '\\xd8' in position 4:", message[0])
+        finally:
+            handler.close()
+            with open('test.log', encoding='utf-8') as f:
+                data = f.read().strip()
+            os.remove('test.log')
+            # didn't write anything due to the encoding error
+            self.assertEqual(data, r'')
+
+
     def _test_log(self, method, level=None):
         # logging.root has no handlers so basicConfig should be called
         called = []

Misc/NEWS.d/next/Library/2019-06-09-17-22-33.bpo-37111.2I0z2k.rst

@@ -0,0 +1 @@
+Added ``encoding`` and ``errors`` keyword parameters to ``logging.basicConfig``.