From 1be31759929c67a3f0b8d11ac8a48ab881760fa8 Mon Sep 17 00:00:00 2001
From: Guido van Rossum <guido@python.org>
Date: Tue, 28 Jan 2003 15:19:53 +0000
Subject: [PATCH] Add a few comments.  Change the way the protocol is checked
 (it must be one of 0, 1 or 2).

I should note that the previous checkin also added NEWOBJ support to
the unpickler -- but there's nothing yet that generates this.
---
 Lib/pickle.py | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/Lib/pickle.py b/Lib/pickle.py
index dffdc2c4105..6045c84044a 100644
--- a/Lib/pickle.py
+++ b/Lib/pickle.py
@@ -158,6 +158,9 @@ del x
 
 _quotes = ["'", '"']
 
+
+# Pickling machinery
+
 class Pickler:
 
     def __init__(self, file, proto=1):
@@ -178,11 +181,11 @@ class Pickler:
         object, or any other custom object that meets this interface.
 
         """
-        if not 0 <= proto <= 2:
+        if proto not in (0, 1, 2):
             raise ValueError, "pickle protocol must be 0, 1 or 2"
         self.write = file.write
         self.memo = {}
-        self.proto = proto
+        self.proto = int(proto)
         self.bin = proto >= 1
 
     def clear_memo(self):
@@ -639,6 +642,7 @@ class Pickler:
     dispatch[BuiltinFunctionType] = save_global
     dispatch[TypeType] = save_global
 
+# Pickling helpers
 
 def _keep_alive(x, memo):
     """Keeps a reference to the object x in the memo.
@@ -683,6 +687,8 @@ def whichmodule(func, funcname):
     return name
 
 
+# Unpickling machinery
+
 class Unpickler:
 
     def __init__(self, file):