diff -r 9fcfdb53e8af Lib/codecs.py
--- a/Lib/codecs.py	Thu Nov 26 23:52:34 2015 +0200
+++ b/Lib/codecs.py	Sat Nov 28 15:45:46 2015 +0200
@@ -335,6 +335,13 @@ class BufferedIncrementalDecoder(Increme
         # ignore additional state info
         self.buffer = state[0]
 
+
+def _getattr_proxy(self, name, _getattr=getattr):
+    # Public attribute lookups are delegated to the underlying stream
+    if name[:1] == '_':
+        raise AttributeError(name)
+    return _getattr(self.__dict__['stream'], name)
+
 #
 # The StreamWriter and StreamReader class provide generic working
 # interfaces which can be used to implement new encoding submodules
@@ -400,19 +407,15 @@ class StreamWriter(Codec):
         if whence == 0 and offset == 0:
             self.reset()
 
-    def __getattr__(self, name,
-                    getattr=getattr):
-
-        """ Inherit all other methods from the underlying stream.
-        """
-        return getattr(self.stream, name)
-
     def __enter__(self):
         return self
 
     def __exit__(self, type, value, tb):
         self.stream.close()
 
+    # Inherit all other public methods from the underlying stream.
+    __getattr__ = _getattr_proxy
+
 ###
 
 class StreamReader(Codec):
@@ -440,8 +443,7 @@ class StreamReader(Codec):
         self.stream = stream
         self.errors = errors
         self.bytebuffer = b""
-        self._empty_charbuffer = self.charbuffertype()
-        self.charbuffer = self._empty_charbuffer
+        self.charbuffer = self.charbuffertype()
         self.linebuffer = None
 
     def decode(self, input, errors='strict'):
@@ -476,7 +478,7 @@ class StreamReader(Codec):
         """
         # If we have lines cached, first merge them back into characters
         if self.linebuffer:
-            self.charbuffer = self._empty_charbuffer.join(self.linebuffer)
+            self.charbuffer = self.charbuffer[:0].join(self.linebuffer)
             self.linebuffer = None
 
         # read until we get the required number of characters (if available)
@@ -518,7 +520,7 @@ class StreamReader(Codec):
         if chars < 0:
             # Return everything we've got
             result = self.charbuffer
-            self.charbuffer = self._empty_charbuffer
+            self.charbuffer = self.charbuffer[:0]
         else:
             # Return the first chars characters
             result = self.charbuffer[:chars]
@@ -549,7 +551,7 @@ class StreamReader(Codec):
             return line
 
         readsize = size or 72
-        line = self._empty_charbuffer
+        line = self.charbuffer[:0]
         # If size is given, we call read() only once
         while True:
             data = self.read(readsize, firstline=True)
@@ -573,7 +575,7 @@ class StreamReader(Codec):
                         # cache the remaining lines
                         lines[-1] += self.charbuffer
                         self.linebuffer = lines
-                        self.charbuffer = None
+                        self.charbuffer = self.charbuffer[:0]
                     else:
                         # only one remaining line, put it back into charbuffer
                         self.charbuffer = lines[0] + self.charbuffer
@@ -584,7 +586,7 @@ class StreamReader(Codec):
                 line0withoutend = lines[0].splitlines(keepends=False)[0]
                 if line0withend != line0withoutend: # We really have a line end
                     # Put the rest back together and keep it until the next call
-                    self.charbuffer = self._empty_charbuffer.join(lines[1:]) + \
+                    self.charbuffer = self.charbuffer[:0].join(lines[1:]) + \
                                       self.charbuffer
                     if keepends:
                         line = line0withend
@@ -625,7 +627,7 @@ class StreamReader(Codec):
 
         """
         self.bytebuffer = b""
-        self.charbuffer = self._empty_charbuffer
+        self.charbuffer = self.charbuffer[:0]
         self.linebuffer = None
 
     def seek(self, offset, whence=0):
@@ -647,19 +649,15 @@ class StreamReader(Codec):
     def __iter__(self):
         return self
 
-    def __getattr__(self, name,
-                    getattr=getattr):
-
-        """ Inherit all other methods from the underlying stream.
-        """
-        return getattr(self.stream, name)
-
     def __enter__(self):
         return self
 
     def __exit__(self, type, value, tb):
         self.stream.close()
 
+    # Inherit all other public methods from the underlying stream.
+    __getattr__ = _getattr_proxy
+
 ###
 
 class StreamReaderWriter:
@@ -732,13 +730,6 @@ class StreamReaderWriter:
         if whence == 0 and offset == 0:
             self.writer.reset()
 
-    def __getattr__(self, name,
-                    getattr=getattr):
-
-        """ Inherit all other methods from the underlying stream.
-        """
-        return getattr(self.stream, name)
-
     # these are needed to make "with codecs.open(...)" work properly
 
     def __enter__(self):
@@ -747,6 +738,9 @@ class StreamReaderWriter:
     def __exit__(self, type, value, tb):
         self.stream.close()
 
+    # Inherit all other public methods from the underlying stream.
+    __getattr__ = _getattr_proxy
+
 ###
 
 class StreamRecoder:
@@ -844,19 +838,15 @@ class StreamRecoder:
         self.reader.reset()
         self.writer.reset()
 
-    def __getattr__(self, name,
-                    getattr=getattr):
-
-        """ Inherit all other methods from the underlying stream.
-        """
-        return getattr(self.stream, name)
-
     def __enter__(self):
         return self
 
     def __exit__(self, type, value, tb):
         self.stream.close()
 
+    # Inherit all other public methods from the underlying stream.
+    __getattr__ = _getattr_proxy
+
 ### Shortcuts
 
 def open(filename, mode='r', encoding=None, errors='strict', buffering=1):