"""Create portable serialized representations of Python objects.
See module copyreg for a mechanism for registering custom picklers.
See module pickletools source for extensive comments.
Classes:
Pickler
Unpickler
Functions:
dump(object, file)
dumps(object) -> string
load(file) -> object
loads(string) -> object
Misc variables:
__version__
format_version
compatible_formats
"""
from types import FunctionType
from copyreg import dispatch_table
from copyreg import _extension_registry, _inverted_registry, _extension_cache
from itertools import islice
import sys
from sys import maxsize
from struct import pack, unpack
import re
import io
import codecs
import _compat_pickle
__all__ = ["PickleError", "PicklingError", "UnpicklingError", "Pickler",
"Unpickler", "dump", "dumps", "load", "loads"]
# Shortcut for use in isinstance testing
bytes_types = (bytes, bytearray)
# These are purely informational; no code uses these.
format_version = "4.0" # File format version we write
compatible_formats = ["1.0", # Original protocol 0
"1.1", # Protocol 0 with INST added
"1.2", # Original protocol 1
"1.3", # Protocol 1 with BINFLOAT added
"2.0", # Protocol 2
"3.0", # Protocol 3
"4.0", # Protocol 4
] # Old format versions we can read
# This is the highest protocol number we know how to read.
HIGHEST_PROTOCOL = 4
# The protocol we write by default. May be less than HIGHEST_PROTOCOL.
# We intentionally write a protocol that Python 2.x cannot read;
# there are too many issues with that.
DEFAULT_PROTOCOL = 3
class PickleError(Exception):
"""A common base class for the other pickling exceptions."""
pass
class PicklingError(PickleError):
"""This exception is raised when an unpicklable object is passed to the
dump() method.
"""
pass
class UnpicklingError(PickleError):
"""This exception is raised when there is a problem unpickling an object,
such as a security violation.
Note that other exceptions may also be raised during unpickling, including
(but not necessarily limited to) AttributeError, EOFError, ImportError,
and IndexError.
"""
pass
# An instance of _Stop is raised by Unpickler.load_stop() in response to
# the STOP opcode, passing the object that is the result of unpickling.
class _Stop(Exception):
def __init__(self, value):
self.value = value
# Jython has PyStringMap; it's a dict subclass with string keys
try:
from org.python.core import PyStringMap
except ImportError:
PyStringMap = None
# Pickle opcodes. See pickletools.py for extensive docs. The listing
# here is in kind-of alphabetical order of 1-character pickle code.
# pickletools groups them by purpose.
MARK = b'(' # push special markobject on stack
STOP = b'.' # every pickle ends with STOP
POP = b'0' # discard topmost stack item
POP_MARK = b'1' # discard stack top through topmost markobject
DUP = b'2' # duplicate top stack item
FLOAT = b'F' # push float object; decimal string argument
INT = b'I' # push integer or bool; decimal string argument
BININT = b'J' # push four-byte signed int
BININT1 = b'K' # push 1-byte unsigned int
LONG = b'L' # push long; decimal string argument
BININT2 = b'M' # push 2-byte unsigned int
NONE = b'N' # push None
PERSID = b'P' # push persistent object; id is taken from string arg
BINPERSID = b'Q' # " " " ; " " " " stack
REDUCE = b'R' # apply callable to argtuple, both on stack
STRING = b'S' # push string; NL-terminated string argument
BINSTRING = b'T' # push string; counted binary string argument
SHORT_BINSTRING= b'U' # " " ; " " " " < 256 bytes
UNICODE = b'V' # push Unicode string; raw-unicode-escaped'd argument
BINUNICODE = b'X' # " " " ; counted UTF-8 string argument
APPEND = b'a' # append stack top to list below it
BUILD = b'b' # call __setstate__ or __dict__.update()
GLOBAL = b'c' # push self.find_class(modname, name); 2 string args
DICT = b'd' # build a dict from stack items
EMPTY_DICT = b'}' # push empty dict
APPENDS = b'e' # extend list on stack by topmost stack slice
GET = b'g' # push item from memo on stack; index is string arg
BINGET = b'h' # " " " " " " ; " " 1-byte arg
INST = b'i' # build & push class instance
LONG_BINGET = b'j' # push item from memo on stack; index is 4-byte arg
LIST = b'l' # build list from topmost stack items
EMPTY_LIST = b']' # push empty list
OBJ = b'o' # build & push class instance
PUT = b'p' # store stack top in memo; index is string arg
BINPUT = b'q' # " " " " " ; " " 1-byte arg
LONG_BINPUT = b'r' # " " " " " ; " " 4-byte arg
SETITEM = b's' # add key+value pair to dict
TUPLE = b't' # build tuple from topmost stack items
EMPTY_TUPLE = b')' # push empty tuple
SETITEMS = b'u' # modify dict by adding topmost key+value pairs
BINFLOAT = b'G' # push float; arg is 8-byte float encoding
TRUE = b'I01\n' # not an opcode; see INT docs in pickletools.py
FALSE = b'I00\n' # not an opcode; see INT docs in pickletools.py
# Protocol 2
PROTO = b'\x80' # identify pickle protocol
NEWOBJ = b'\x81' # build object by applying cls.__new__ to argtuple
EXT1 = b'\x82' # push object from extension registry; 1-byte index
EXT2 = b'\x83' # ditto, but 2-byte index
EXT4 = b'\x84' # ditto, but 4-byte index
TUPLE1 = b'\x85' # build 1-tuple from stack top
TUPLE2 = b'\x86' # build 2-tuple from two topmost stack items
TUPLE3 = b'\x87' # build 3-tuple from three topmost stack items
NEWTRUE = b'\x88' # push True
NEWFALSE = b'\x89' # push False
LONG1 = b'\x8a' # push long from < 256 bytes
LONG4 = b'\x8b' # push really big long
_tuplesize2code = [EMPTY_TUPLE, TUPLE1, TUPLE2, TUPLE3]
# Protocol 3 (Python 3.x)
BINBYTES = b'B' # push bytes; counted binary string argument
SHORT_BINBYTES = b'C' # " " ; " " " " < 256 bytes
# Protocol 4
SHORT_BINUNICODE = b'\x8c' # push short string; UTF-8 length < 256 bytes
BINUNICODE8 = b'\x8d' # push very long string
BINBYTES8 = b'\x8e' # push very long bytes string
EMPTY_SET = b'\x8f' # push empty set on the stack
ADDITEMS = b'\x90' # modify set by adding topmost stack items
FROZENSET = b'\x91' # build frozenset from topmost stack items
NEWOBJ_EX = b'\x92' # like NEWOBJ but work with keyword only arguments
STACK_GLOBAL = b'\x93' # same as GLOBAL but using names on the stacks
MEMOIZE = b'\x94' # store top of the stack in memo
FRAME = b'\x95' # indicate the beginning of a new frame
__all__.extend([x for x in dir() if re.match("[A-Z][A-Z0-9_]+$", x)])
class _Framer:
_FRAME_SIZE_TARGET = 64 * 1024
def __init__(self, file_write):
self.file_write = file_write
self.current_frame = None
def start_framing(self):
self.current_frame = io.BytesIO()
def end_framing(self):
if self.current_frame and self.current_frame.tell() > 0:
self.commit_frame(force=True)
self.current_frame = None
def commit_frame(self, force=False):
if self.current_frame:
f = self.current_frame
if f.tell() >= self._FRAME_SIZE_TARGET or force:
with f.getbuffer() as data:
n = len(data)
write = self.file_write
write(FRAME)
write(pack(" 1:
raise AttributeError("Can't get qualified attribute {!r} on {!r}; " +
"use protocols >= 4 to enable support"
.format(name, obj))
for subpath in dotted_path:
if subpath == '
= 4:
self.write(SHORT_BINUNICODE + pack(" 0xffffffff and self.proto >= 4:
self.write(BINUNICODE8 + pack("
= 2:
for element in obj:
save(element)
# Subtle. Same as in the big comment below.
if id(obj) in memo:
get = self.get(memo[id(obj)][0])
self.write(POP * n + get)
else:
self.write(_tuplesize2code[n])
self.memoize(obj)
return
# proto 0 or proto 1 and tuple isn't empty, or proto > 1 and tuple
# has more than 3 elements.
write = self.write
write(MARK)
for element in obj:
save(element)
if id(obj) in memo:
# Subtle. d was not in memo when we entered save_tuple(), so
# the process of saving the tuple's elements must have saved
# the tuple itself: the tuple is recursive. The proper action
# now is to throw away everything we put on the stack, and
# simply GET the tuple (it's already constructed). This check
# could have been done in the "for element" loop instead, but
# recursive tuples are a rare thing.
get = self.get(memo[id(obj)][0])
if self.bin:
write(POP_MARK + get)
else: # proto 0 -- POP_MARK not available
write(POP * (n+1) + get)
return
# No recursion.
write(TUPLE)
self.memoize(obj)
dispatch[tuple] = save_tuple
def save_list(self, obj):
if self.bin:
self.write(EMPTY_LIST)
else: # proto 0 -- can't use EMPTY_LIST
self.write(MARK + LIST)
self.memoize(obj)
self._batch_appends(obj)
dispatch[list] = save_list
_BATCHSIZE = 1000
def _batch_appends(self, items):
# Helper to batch up APPENDS sequences
save = self.save
write = self.write
if not self.bin:
for x in items:
save(x)
write(APPEND)
return
it = iter(items)
while True:
tmp = list(islice(it, self._BATCHSIZE))
n = len(tmp)
if n > 1:
write(MARK)
for x in tmp:
save(x)
write(APPENDS)
elif n:
save(tmp[0])
write(APPEND)
# else tmp is empty, and we're done
if n < self._BATCHSIZE:
return
def save_dict(self, obj):
if self.bin:
self.write(EMPTY_DICT)
else: # proto 0 -- can't use EMPTY_DICT
self.write(MARK + DICT)
self.memoize(obj)
self._batch_setitems(obj.items())
dispatch[dict] = save_dict
if PyStringMap is not None:
dispatch[PyStringMap] = save_dict
def _batch_setitems(self, items):
# Helper to batch up SETITEMS sequences; proto >= 1 only
save = self.save
write = self.write
if not self.bin:
for k, v in items:
save(k)
save(v)
write(SETITEM)
return
it = iter(items)
while True:
tmp = list(islice(it, self._BATCHSIZE))
n = len(tmp)
if n > 1:
write(MARK)
for k, v in tmp:
save(k)
save(v)
write(SETITEMS)
elif n:
k, v = tmp[0]
save(k)
save(v)
write(SETITEM)
# else tmp is empty, and we're done
if n < self._BATCHSIZE:
return
def save_set(self, obj):
save = self.save
write = self.write
if self.proto < 4:
self.save_reduce(set, (list(obj),), obj=obj)
return
write(EMPTY_SET)
self.memoize(obj)
it = iter(obj)
while True:
batch = list(islice(it, self._BATCHSIZE))
n = len(batch)
if n > 0:
write(MARK)
for item in batch:
save(item)
write(ADDITEMS)
if n < self._BATCHSIZE:
return
dispatch[set] = save_set
def save_frozenset(self, obj):
save = self.save
write = self.write
if self.proto < 4:
self.save_reduce(frozenset, (list(obj),), obj=obj)
return
write(MARK)
for item in obj:
save(item)
if id(obj) in self.memo:
# If the object is already in the memo, this means it is
# recursive. In this case, throw away everything we put on the
# stack, and fetch the object back from the memo.
write(POP_MARK + self.get(self.memo[id(obj)][0]))
return
write(FROZENSET)
self.memoize(obj)
dispatch[frozenset] = save_frozenset
def save_global(self, obj, name=None):
write = self.write
memo = self.memo
if name is None and self.proto >= 4:
name = getattr(obj, '__qualname__', None)
if name is None:
name = obj.__name__
module_name = whichmodule(obj, name, allow_qualname=self.proto >= 4)
try:
__import__(module_name, level=0)
module = sys.modules[module_name]
obj2 = _getattribute(module, name, allow_qualname=self.proto >= 4)
except (ImportError, KeyError, AttributeError):
raise PicklingError(
"Can't pickle %r: it's not found as %s.%s" %
(obj, module_name, name))
else:
if obj2 is not obj:
raise PicklingError(
"Can't pickle %r: it's not the same object as %s.%s" %
(obj, module_name, name))
if self.proto >= 2:
code = _extension_registry.get((module_name, name))
if code:
assert code > 0
if code <= 0xff:
write(EXT1 + pack("= 3.
if self.proto >= 4:
self.save(module_name)
self.save(name)
write(STACK_GLOBAL)
elif self.proto >= 3:
write(GLOBAL + bytes(module_name, "utf-8") + b'\n' +
bytes(name, "utf-8") + b'\n')
else:
if self.fix_imports:
r_name_mapping = _compat_pickle.REVERSE_NAME_MAPPING
r_import_mapping = _compat_pickle.REVERSE_IMPORT_MAPPING
if (module_name, name) in r_name_mapping:
module_name, name = r_name_mapping[(module_name, name)]
elif module_name in r_import_mapping:
module_name = r_import_mapping[module_name]
try:
write(GLOBAL + bytes(module_name, "ascii") + b'\n' +
bytes(name, "ascii") + b'\n')
except UnicodeEncodeError:
raise PicklingError(
"can't pickle global identifier '%s.%s' using "
"pickle protocol %i" % (module, name, self.proto))
self.memoize(obj)
def save_type(self, obj):
if obj is type(None):
return self.save_reduce(type, (None,), obj=obj)
elif obj is type(NotImplemented):
return self.save_reduce(type, (NotImplemented,), obj=obj)
elif obj is type(...):
return self.save_reduce(type, (...,), obj=obj)
return self.save_global(obj)
dispatch[FunctionType] = save_global
dispatch[type] = save_type
# Unpickling machinery
class _Unpickler:
def __init__(self, file, *, fix_imports=True,
encoding="ASCII", errors="strict"):
"""This takes a binary file for reading a pickle data stream.
The protocol version of the pickle is detected automatically, so
no proto argument is needed.
The argument *file* must have two methods, a read() method that
takes an integer argument, and a readline() method that requires
no arguments. Both methods should return bytes. Thus *file*
can be a binary file object opened for reading, an io.BytesIO
object, or any other custom object that meets this interface.
The file-like object must have two methods, a read() method
that takes an integer argument, and a readline() method that
requires no arguments. Both methods should return bytes.
Thus file-like object can be a binary file object opened for
reading, a BytesIO object, or any other custom object that
meets this interface.
Optional keyword arguments are *fix_imports*, *encoding* and
*errors*, which are used to control compatiblity support for
pickle stream generated by Python 2. If *fix_imports* is True,
pickle will try to map the old Python 2 names to the new names
used in Python 3. The *encoding* and *errors* tell pickle how
to decode 8-bit string instances pickled by Python 2; these
default to 'ASCII' and 'strict', respectively. *encoding* can be
'bytes' to read theses 8-bit string instances as bytes objects.
"""
self._file_readline = file.readline
self._file_read = file.read
self.memo = {}
self.encoding = encoding
self.errors = errors
self.proto = 0
self.fix_imports = fix_imports
def load(self):
"""Read a pickled object representation from the open file.
Return the reconstituted object hierarchy specified in the file.
"""
# Check whether Unpickler was initialized correctly. This is
# only needed to mimic the behavior of _pickle.Unpickler.dump().
if not hasattr(self, "_file_read"):
raise UnpicklingError("Unpickler.__init__() was not called by "
"%s.__init__()" % (self.__class__.__name__,))
self._unframer = _Unframer(self._file_read, self._file_readline)
self.read = self._unframer.read
self.readline = self._unframer.readline
self.mark = object() # any new unique object
self.stack = []
self.append = self.stack.append
self.proto = 0
read = self.read
dispatch = self.dispatch
try:
while True:
key = read(1)
if not key:
raise EOFError
assert isinstance(key, bytes_types)
dispatch[key[0]](self)
except _Stop as stopinst:
return stopinst.value
# Return largest index k such that self.stack[k] is self.mark.
# If the stack doesn't contain a mark, eventually raises IndexError.
# This could be sped by maintaining another stack, of indices at which
# the mark appears. For that matter, the latter stack would suffice,
# and we wouldn't need to push mark objects on self.stack at all.
# Doing so is probably a good thing, though, since if the pickle is
# corrupt (or hostile) we may get a clue from finding self.mark embedded
# in unpickled objects.
def marker(self):
stack = self.stack
mark = self.mark
k = len(stack)-1
while stack[k] is not mark: k = k-1
return k
def persistent_load(self, pid):
raise UnpicklingError("unsupported persistent id encountered")
dispatch = {}
def load_proto(self):
proto = self.read(1)[0]
if not 0 <= proto <= HIGHEST_PROTOCOL:
raise ValueError("unsupported pickle protocol: %d" % proto)
self.proto = proto
dispatch[PROTO[0]] = load_proto
def load_frame(self):
frame_size, = unpack('
sys.maxsize:
raise ValueError("frame size > sys.maxsize: %d" % frame_size)
self._unframer.load_frame(frame_size)
dispatch[FRAME[0]] = load_frame
def load_persid(self):
pid = self.readline()[:-1].decode("ascii")
self.append(self.persistent_load(pid))
dispatch[PERSID[0]] = load_persid
def load_binpersid(self):
pid = self.stack.pop()
self.append(self.persistent_load(pid))
dispatch[BINPERSID[0]] = load_binpersid
def load_none(self):
self.append(None)
dispatch[NONE[0]] = load_none
def load_false(self):
self.append(False)
dispatch[NEWFALSE[0]] = load_false
def load_true(self):
self.append(True)
dispatch[NEWTRUE[0]] = load_true
def load_int(self):
data = self.readline()
if data == FALSE[1:]:
val = False
elif data == TRUE[1:]:
val = True
else:
val = int(data, 0)
self.append(val)
dispatch[INT[0]] = load_int
def load_binint(self):
self.append(unpack('d', self.read(8))[0])
dispatch[BINFLOAT[0]] = load_binfloat
def _decode_string(self, value):
# Used to allow strings from Python 2 to be decoded either as
# bytes or Unicode strings. This should be used only with the
# STRING, BINSTRING and SHORT_BINSTRING opcodes.
if self.encoding == "bytes":
return value
else:
return value.decode(self.encoding, self.errors)
def load_string(self):
data = self.readline()[:-1]
# Strip outermost quotes
if len(data) >= 2 and data[0] == data[-1] and data[0] in b'"\'':
data = data[1:-1]
else:
raise UnpicklingError("the STRING opcode argument must be quoted")
self.append(self._decode_string(codecs.escape_decode(data)[0]))
dispatch[STRING[0]] = load_string
def load_binstring(self):
# Deprecated BINSTRING uses signed 32-bit length
len, = unpack(' maxsize:
raise UnpicklingError("BINBYTES exceeds system's maximum size "
"of %d bytes" % maxsize)
self.append(self.read(len))
dispatch[BINBYTES[0]] = load_binbytes
def load_unicode(self):
self.append(str(self.readline()[:-1], 'raw-unicode-escape'))
dispatch[UNICODE[0]] = load_unicode
def load_binunicode(self):
len, = unpack(' maxsize:
raise UnpicklingError("BINUNICODE exceeds system's maximum size "
"of %d bytes" % maxsize)
self.append(str(self.read(len), 'utf-8', 'surrogatepass'))
dispatch[BINUNICODE[0]] = load_binunicode
def load_binunicode8(self):
len, = unpack('
maxsize:
raise UnpicklingError("BINUNICODE8 exceeds system's maximum size "
"of %d bytes" % maxsize)
self.append(str(self.read(len), 'utf-8', 'surrogatepass'))
dispatch[BINUNICODE8[0]] = load_binunicode8
def load_binbytes8(self):
len, = unpack('
maxsize:
raise UnpicklingError("BINBYTES8 exceeds system's maximum size "
"of %d bytes" % maxsize)
self.append(self.read(len))
dispatch[BINBYTES8[0]] = load_binbytes8
def load_short_binstring(self):
len = self.read(1)[0]
data = self.read(len)
self.append(self._decode_string(data))
dispatch[SHORT_BINSTRING[0]] = load_short_binstring
def load_short_binbytes(self):
len = self.read(1)[0]
self.append(self.read(len))
dispatch[SHORT_BINBYTES[0]] = load_short_binbytes
def load_short_binunicode(self):
len = self.read(1)[0]
self.append(str(self.read(len), 'utf-8', 'surrogatepass'))
dispatch[SHORT_BINUNICODE[0]] = load_short_binunicode
def load_tuple(self):
k = self.marker()
self.stack[k:] = [tuple(self.stack[k+1:])]
dispatch[TUPLE[0]] = load_tuple
def load_empty_tuple(self):
self.append(())
dispatch[EMPTY_TUPLE[0]] = load_empty_tuple
def load_tuple1(self):
self.stack[-1] = (self.stack[-1],)
dispatch[TUPLE1[0]] = load_tuple1
def load_tuple2(self):
self.stack[-2:] = [(self.stack[-2], self.stack[-1])]
dispatch[TUPLE2[0]] = load_tuple2
def load_tuple3(self):
self.stack[-3:] = [(self.stack[-3], self.stack[-2], self.stack[-1])]
dispatch[TUPLE3[0]] = load_tuple3
def load_empty_list(self):
self.append([])
dispatch[EMPTY_LIST[0]] = load_empty_list
def load_empty_dictionary(self):
self.append({})
dispatch[EMPTY_DICT[0]] = load_empty_dictionary
def load_empty_set(self):
self.append(set())
dispatch[EMPTY_SET[0]] = load_empty_set
def load_frozenset(self):
k = self.marker()
self.stack[k:] = [frozenset(self.stack[k+1:])]
dispatch[FROZENSET[0]] = load_frozenset
def load_list(self):
k = self.marker()
self.stack[k:] = [self.stack[k+1:]]
dispatch[LIST[0]] = load_list
def load_dict(self):
k = self.marker()
items = self.stack[k+1:]
d = {items[i]: items[i+1]
for i in range(0, len(items), 2)}
self.stack[k:] = [d]
dispatch[DICT[0]] = load_dict
# INST and OBJ differ only in how they get a class object. It's not
# only sensible to do the rest in a common routine, the two routines
# previously diverged and grew different bugs.
# klass is the class to instantiate, and k points to the topmost mark
# object, following which are the arguments for klass.__init__.
def _instantiate(self, klass, k):
args = tuple(self.stack[k+1:])
del self.stack[k:]
if (args or not isinstance(klass, type) or
hasattr(klass, "__getinitargs__")):
try:
value = klass(*args)
except TypeError as err:
raise TypeError("in constructor for %s: %s" %
(klass.__name__, str(err)), sys.exc_info()[2])
else:
value = klass.__new__(klass)
self.append(value)
def load_inst(self):
module = self.readline()[:-1].decode("ascii")
name = self.readline()[:-1].decode("ascii")
klass = self.find_class(module, name)
self._instantiate(klass, self.marker())
dispatch[INST[0]] = load_inst
def load_obj(self):
# Stack is ... markobject classobject arg1 arg2 ...
k = self.marker()
klass = self.stack.pop(k+1)
self._instantiate(klass, k)
dispatch[OBJ[0]] = load_obj
def load_newobj(self):
args = self.stack.pop()
cls = self.stack.pop()
obj = cls.__new__(cls, *args)
self.append(obj)
dispatch[NEWOBJ[0]] = load_newobj
def load_newobj_ex(self):
kwargs = self.stack.pop()
args = self.stack.pop()
cls = self.stack.pop()
obj = cls.__new__(cls, *args, **kwargs)
self.append(obj)
dispatch[NEWOBJ_EX[0]] = load_newobj_ex
def load_global(self):
module = self.readline()[:-1].decode("utf-8")
name = self.readline()[:-1].decode("utf-8")
klass = self.find_class(module, name)
self.append(klass)
dispatch[GLOBAL[0]] = load_global
def load_stack_global(self):
name = self.stack.pop()
module = self.stack.pop()
if type(name) is not str or type(module) is not str:
raise UnpicklingError("STACK_GLOBAL requires str")
self.append(self.find_class(module, name))
dispatch[STACK_GLOBAL[0]] = load_stack_global
def load_ext1(self):
code = self.read(1)[0]
self.get_extension(code)
dispatch[EXT1[0]] = load_ext1
def load_ext2(self):
code, = unpack('