diff options
Diffstat (limited to 'Lib')
-rw-r--r-- | Lib/pickle.py | 77 |
1 files changed, 61 insertions, 16 deletions
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 @@ Unlike the built-in marshal module, pickle handles the following correctly: - 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 @@ define a method __getinitargs__ (XXX not a pretty name!), which should 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 @@ The following types can be pickled: - 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 @@ the old value, not the modified one. (XXX There are two problems here: 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 @@ TUPLE = 't' LIST = 'l' DICT = 'd' INST = 'i' +CLASS = 'c' GET = 'g' PUT = 'p' APPEND = 'a' @@ -300,8 +304,8 @@ class Pickler: 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 @@ class Pickler: 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 @@ class Unpickler: 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 @@ class Unpickler: 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 @@ class Unpickler: 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__) |