Jim Fulton writes:

"""
I've attached a long overdue patch to pickle.py to bring it to format
1.3, which is the same as 1.2 except that the binary float format
is supported.  This is done using the new platform-indepent format
features of struct.

This patch also gets rid of the undocumented obsolete Pickler
dump_special method.
"""

Lib/pickle.py

@@ -27,10 +27,13 @@ __version__ = "$Revision$"       # Code version
 
 from types import *
 from copy_reg import dispatch_table, safe_constructors
-import string, marshal, sys
+import string
+import marshal
+import sys
+import struct
 
-format_version = "1.2"                  # File format version we write
-compatible_formats = ["1.0", "1.1"]     # Old format versions we can read
+format_version = "1.3"                     # File format version we write
+compatible_formats = ["1.0", "1.1", "1.2"] # Old format versions we can read
 
 mdumps = marshal.dumps
 mloads = marshal.loads
@@ -81,6 +84,7 @@ SETITEM         = 's'
 TUPLE           = 't'
 EMPTY_TUPLE     = ')'
 SETITEMS        = 'u'
+BINFLOAT        = 'G'
 
 class Pickler:
 
@@ -93,14 +97,6 @@ class Pickler:
         self.save(object)
         self.write(STOP)
 
-    def dump_special(self, callable, args, state = None):
-        if type(args) is not TupleType and args is not None:
-            raise PicklingError, "Second argument to dump_special " \
-                                 "must be a tuple"
-
-        self.save_reduce(callable, args, state)
-        self.write(STOP)
-
     def put(self, i):
         if (self.bin):
             s = mdumps(i)[1:]
@@ -252,8 +248,11 @@ class Pickler:
         self.write(LONG + `object` + '\n')
     dispatch[LongType] = save_long
 
-    def save_float(self, object):
-        self.write(FLOAT + `object` + '\n')
+    def save_float(self, object, pack=struct.pack):
+        if self.bin:
+            self.write(BINFLOAT + pack('>d', object))
+        else:
+            self.write(FLOAT + `object` + '\n')
     dispatch[FloatType] = save_float
 
     def save_string(self, object):
@@ -552,6 +551,10 @@ class Unpickler:
         self.append(string.atof(self.readline()[:-1]))
     dispatch[FLOAT] = load_float
 
+    def load_binfloat(self, unpack=struct.unpack):
+        self.append(unpack('>d', self.read(8))[0])
+    dispatch[BINFLOAT] = load_binfloat
+
     def load_string(self):
         self.append(eval(self.readline()[:-1],
                          {'__builtins__': {}})) # Let's be careful