The C pickle now knows how to deal with a proto= argument. Assorted
code cleanups, and purged more references to text-vs-binary modes.
diff --git a/Lib/pickle.py b/Lib/pickle.py
index 45bc38c..92b4802 100644
--- a/Lib/pickle.py
+++ b/Lib/pickle.py
@@ -174,13 +174,17 @@
protocol; supported protocols are 0, 1, 2. The default
protocol is 0, to be backwards compatible. (Protocol 0 is the
only protocol that can be written to a file opened in text
- mode and read back successfully.)
+ mode and read back successfully. When using a protocol higher
+ than 0, make sure the file is opened in binary mode, both when
+ pickling and unpickling.)
Protocol 1 is more efficient than protocol 0; protocol 2 is
more efficient than protocol 1.
Specifying a negative protocol version selects the highest
- protocol version supported.
+ protocol version supported. The higher the protocol used, the
+ more recent the version of Python needed to read the pickle
+ produced.
The file parameter must have a write() method that accepts a single
string argument. It can thus be an open file object, a StringIO
@@ -209,12 +213,7 @@
self.memo.clear()
def dump(self, obj):
- """Write a pickled representation of obj to the open file.
-
- Either the binary or ASCII format will be used, depending on the
- value of the bin flag passed to the constructor.
-
- """
+ """Write a pickled representation of obj to the open file."""
if self.proto >= 2:
self.write(PROTO + chr(self.proto))
self.save(obj)
@@ -931,9 +930,8 @@
def __init__(self, file):
"""This takes a file-like object for reading a pickle data stream.
- This class automatically determines whether the data stream was
- written in binary mode or not, so it does not need a flag as in
- the Pickler class factory.
+ The protocol version of the pickle is detected automatically, so no
+ proto argument is needed.
The file-like object must have two methods, a read() method that
takes an integer argument, and a readline() method that requires no