pickle classes; add format_version, load(s)/dump(s) shortcuts
diff --git a/Lib/pickle.py b/Lib/pickle.py
index 44447d4..404690e 100644
--- a/Lib/pickle.py
+++ b/Lib/pickle.py
@@ -17,7 +17,7 @@
- recursive objects
- pointer sharing
-- class instances
+- classes and class instances
Pickle is Python-specific. This has the advantage that there are no
restrictions imposed by external standards such as CORBA (which probably
@@ -62,7 +62,7 @@
return a *tuple* containing the arguments to be passed to the class
constructor.
-Classes can influence how they are pickled -- if the class defines
+Classes can influence how their instances are pickled -- if the class defines
the method __getstate__, it is called and the return state is pickled
as the contents for the instance, and if the class defines the
method __setstate__, it is called with the unpickled state. (Note
@@ -108,6 +108,7 @@
- strings
- tuples, lists and dictionaries containing only picklable objects
- class instances whose __dict__ or __setstate__() is picklable
+- classes
Attempts to pickle unpicklable objects will raise an exception
after having written an unspecified number of bytes to the file argument.
@@ -125,12 +126,14 @@
I have no answers. Garbage Collection may also become a problem here.)
"""
-__format_version__ = "1.0" # File format version
-__version__ = "1.4" # Code version
+__version__ = "1.5" # Code version
from types import *
import string
+format_version = "1.1" # File format version we write
+compatible_formats = ["1.0"] # Old format versions we can read
+
PicklingError = "pickle.PicklingError"
AtomicTypes = [NoneType, IntType, FloatType, StringType]
@@ -153,6 +156,7 @@
LIST = 'l'
DICT = 'd'
INST = 'i'
+CLASS = 'c'
GET = 'g'
PUT = 'p'
APPEND = 'a'
@@ -300,8 +304,8 @@
self.write(MARK)
for arg in args:
self.save(arg)
- self.write(INST + module + '\n' + name + '\n' +
- PUT + `d` + '\n')
+ self.write(INST + module + '\n' + name + '\n' +
+ PUT + `d` + '\n')
self.memo[d] = object
try:
getstate = object.__getstate__
@@ -313,6 +317,14 @@
self.write(BUILD)
dispatch[InstanceType] = save_inst
+ def save_class(self, object):
+ d = id(object)
+ module = whichmodule(object)
+ name = object.__name__
+ self.write(CLASS + module + '\n' + name + '\n' +
+ PUT + `d` + '\n')
+ dispatch[ClassType] = save_class
+
classmap = {}
@@ -410,6 +422,20 @@
del self.stack[k:]
module = self.readline()[:-1]
name = self.readline()[:-1]
+ klass = self.find_class(module, name)
+ value = apply(klass, args)
+ self.stack.append(value)
+ dispatch[INST] = load_inst
+
+ def load_class(self):
+ module = self.readline()[:-1]
+ name = self.readline()[:-1]
+ klass = self.find_class(module, name)
+ self.stack.append(klass)
+ return klass
+ dispatch[CLASS] = load_class
+
+ def find_class(self, module, name):
env = {}
try:
exec 'from %s import %s' % (module, name) in env
@@ -417,18 +443,15 @@
raise SystemError, \
"Failed to import class %s from module %s" % \
(name, module)
- else:
- klass = env[name]
- if type(klass) != ClassType:
- raise SystemError, \
- "imported object %s from module %s is not a class" % \
- (name, module)
- value = apply(klass, args)
- self.stack.append(value)
- dispatch[INST] = load_inst
+ klass = env[name]
+ if type(klass) != ClassType:
+ raise SystemError, \
+ "Imported object %s from module %s is not a class" % \
+ (name, module)
+ return klass
def load_pop(self):
- del self.stack[-1]
+ del self.stack[-1]
dispatch[POP] = load_pop
def load_dup(self):
@@ -482,6 +505,28 @@
dispatch[STOP] = load_stop
+# Shorthands
+
+def dump(object, file):
+ Pickler(file).dump(object)
+
+def dumps(object):
+ import StringIO
+ file = StringIO.StringIO()
+ Pickler(file).dump(object)
+ return file.getvalue()
+
+def load(file):
+ return Unpickler(file).load()
+
+def loads(str):
+ import StringIO
+ file = StringIO.StringIO(str)
+ return Unpickler(file).load()
+
+
+# The rest is used for testing only
+
class C:
def __cmp__(self, other):
return cmp(self.__dict__, other.__dict__)