Implement an idea by Paul Rubin:
Change pickling format for bools to use a backwards compatible
encoding. This means you can pickle True or False on Python 2.3
and Python 2.2 or before will read it back as 1 or 0. The code
used for pickling bools before would create pickles that could
not be read in previous Python versions.
diff --git a/Lib/pickle.py b/Lib/pickle.py
index 96ee5c1..541624a 100644
--- a/Lib/pickle.py
+++ b/Lib/pickle.py
@@ -101,8 +101,8 @@
EMPTY_TUPLE = ')'
SETITEMS = 'u'
BINFLOAT = 'G'
-TRUE = 'Z'
-FALSE = 'z'
+TRUE = 'I01\n'
+FALSE = 'I00\n'
__all__.extend([x for x in dir() if re.match("[A-Z][A-Z0-9_]+$",x)])
@@ -639,20 +639,18 @@
self.append(None)
dispatch[NONE] = load_none
- def load_false(self):
- self.append(False)
- dispatch[FALSE] = load_false
-
- def load_true(self):
- self.append(True)
- dispatch[TRUE] = load_true
-
def load_int(self):
data = self.readline()
- try:
- self.append(int(data))
- except ValueError:
- self.append(long(data))
+ if data == FALSE[1:]:
+ val = False
+ elif data == TRUE[1:]:
+ val = True
+ else:
+ try:
+ val = int(data)
+ except ValueError:
+ val = long(data)
+ self.append(val)
dispatch[INT] = load_int
def load_binint(self):