Revert my commit 3555cf6f9c98: "Issue #8796: codecs.open() calls the builtin

open() function instead of using StreamReaderWriter. Deprecate StreamReader,
StreamWriter, StreamReaderWriter, StreamRecoder and EncodedFile() of the codec
module. Use the builtin open() function or io.TextIOWrapper instead."

"It has not been approved !" wrote Marc-Andre Lemburg.

Doc/library/codecs.rst

@@ -85,9 +85,6 @@ It defines the following functions:
    In case a search function cannot find a given encoding, it should return
    ``None``.
 
-   .. deprecated:: 3.3
-      *streamreader* and *streamwriter* attributes are now deprecated.
-
 
 .. function:: lookup(encoding)
 
@@ -142,8 +139,6 @@ functions which use :func:`lookup` for the codec lookup:
 
    Raises a :exc:`LookupError` in case the encoding cannot be found.
 
-   .. deprecated:: 3.3
-
 
 .. function:: getwriter(encoding)
 
@@ -152,8 +147,6 @@ functions which use :func:`lookup` for the codec lookup:
 
    Raises a :exc:`LookupError` in case the encoding cannot be found.
 
-   .. deprecated:: 3.3
-
 
 .. function:: register_error(name, error_handler)
 
@@ -222,11 +215,6 @@ utility functions:
    providing transparent encoding/decoding.  The default file mode is ``'r'``
    meaning to open the file in read mode.
 
-   .. note::
-
-      This function is kept for backward compatibility with Python 2, the
-      builtin :func:`open` function should be used instead.
-
    .. note::
 
       The wrapped version's methods will accept and return strings only.  Bytes
@@ -263,8 +251,6 @@ utility functions:
    ``'strict'``, which causes :exc:`ValueError` to be raised in case an encoding
    error occurs.
 
-   .. deprecated:: 3.3
-
 
 .. function:: iterencode(iterator, encoding, errors='strict', **kwargs)
 
@@ -577,9 +563,6 @@ The :class:`StreamWriter` class is a subclass of :class:`Codec` and defines the
 following methods which every stream writer must define in order to be
 compatible with the Python codec registry.
 
-.. deprecated:: 3.3
-   Use the builtin the :class:`io.TextIOWrapper` class.
-
 
 .. class:: StreamWriter(stream[, errors])
 
@@ -645,9 +628,6 @@ The :class:`StreamReader` class is a subclass of :class:`Codec` and defines the
 following methods which every stream reader must define in order to be
 compatible with the Python codec registry.
 
-.. deprecated:: 3.3
-   Use the builtin the :class:`io.TextIOWrapper` class.
-
 
 .. class:: StreamReader(stream[, errors])
 
@@ -748,9 +728,6 @@ and write modes.
 The design is such that one can use the factory functions returned by the
 :func:`lookup` function to construct the instance.
 
-.. deprecated:: 3.3
-   Use the :class:`io.TextIOWrapper` class.
-
 
 .. class:: StreamReaderWriter(stream, Reader, Writer, errors)
 
@@ -775,8 +752,6 @@ which is sometimes useful when dealing with different encoding environments.
 The design is such that one can use the factory functions returned by the
 :func:`lookup` function to construct the instance.
 
-.. deprecated:: 3.3
-
 
 .. class:: StreamRecoder(stream, encode, decode, Reader, Writer, errors)
 

Lib/codecs.py

@@ -345,8 +345,6 @@ class StreamWriter(Codec):
             The set of allowed parameter values can be extended via
             register_error.
         """
-        import warnings
-        warnings.warn('use io.TextIOWrapper', DeprecationWarning, stacklevel=2)
         self.stream = stream
         self.errors = errors
 
@@ -418,8 +416,6 @@ class StreamReader(Codec):
             The set of allowed parameter values can be extended via
             register_error.
         """
-        import warnings
-        warnings.warn('use io.TextIOWrapper', DeprecationWarning, stacklevel=2)
         self.stream = stream
         self.errors = errors
         self.bytebuffer = b""
@@ -850,7 +846,7 @@ class StreamRecoder:
 
 ### Shortcuts
 
-def open(filename, mode='r', encoding=None, errors=None, buffering=1):
+def open(filename, mode='rb', encoding=None, errors='strict', buffering=1):
 
     """ Open an encoded file using the given mode and return
         a wrapped version providing transparent encoding/decoding.
@@ -881,13 +877,18 @@ def open(filename, mode='r', encoding=None, errors=None, buffering=1):
         parameter.
 
     """
-    if encoding is not None:
-        return builtins.open(filename, mode, buffering,
-                             encoding, errors, newline='')
-    else:
-        if 'b' not in mode:
-            mode = mode + 'b'
-        return builtins.open(filename, mode, buffering, encoding, errors)
+    if encoding is not None and \
+       'b' not in mode:
+        # Force opening of the file in binary mode
+        mode = mode + 'b'
+    file = builtins.open(filename, mode, buffering)
+    if encoding is None:
+        return file
+    info = lookup(encoding)
+    srw = StreamReaderWriter(file, info.streamreader, info.streamwriter, errors)
+    # Add attributes to simplify introspection
+    srw.encoding = encoding
+    return srw
 
 def EncodedFile(file, data_encoding, file_encoding=None, errors='strict'):
 

Misc/NEWS

@@ -167,11 +167,6 @@ Library
 - Issue #1625: BZ2File and bz2.decompress() now support multi-stream files.
   Initial patch by Nir Aides.
 
-- Issue #8796: codecs.open() calls the builtin open() function instead of using
-  StreamReaderWriter. Deprecate StreamReader, StreamWriter, StreamReaderWriter,
-  StreamRecoder and EncodedFile() of the codec module. Use the builtin open()
-  function or io.TextIOWrapper instead.
-
 - Issue #12175: BufferedReader.read(-1) now calls raw.readall() if available.
 
 - Issue #12175: FileIO.readall() now only reads the file position and size