- A new pickle protocol (protocol 3) is added with explicit support
for bytes. This is the default protocol. It intentionally cannot
be unpickled by Python 2.x.
- When a pickle written by Python 2.x contains an (8-bit) str
instance, this is now decoded to a (Unicode) str instance. The
encoding used to do this defaults to ASCII, but can be overridden
via two new keyword arguments to the Unpickler class. Previously
this would create bytes instances, which is usually wrong: str
instances are often used to pickle attribute names etc., and text is
more common than binary data anyway.
diff --git a/Lib/pickletools.py b/Lib/pickletools.py
index ca09c03..37dad9b 100644
--- a/Lib/pickletools.py
+++ b/Lib/pickletools.py
@@ -746,6 +746,11 @@
doc="A Python float object.")
pystring = StackObject(
+ name='string',
+ obtype=bytes,
+ doc="A Python (8-bit) string object.")
+
+pybytes = StackObject(
name='bytes',
obtype=bytes,
doc="A Python bytes object.")
@@ -753,7 +758,7 @@
pyunicode = StackObject(
name='str',
obtype=str,
- doc="A Python string object.")
+ doc="A Python (Unicode) string object.")
pynone = StackObject(
name="None",
@@ -868,7 +873,7 @@
assert isinstance(x, StackObject)
self.stack_after = stack_after
- assert isinstance(proto, int) and 0 <= proto <= 2
+ assert isinstance(proto, int) and 0 <= proto <= 3
self.proto = proto
assert isinstance(doc, str)
@@ -995,7 +1000,9 @@
The argument is a repr-style string, with bracketing quote characters,
and perhaps embedded escapes. The argument extends until the next
- newline character.
+ newline character. (Actually, they are decoded into a str instance
+ using the encoding given to the Unpickler constructor. or the default,
+ 'ASCII'.)
"""),
I(name='BINSTRING',
@@ -1008,7 +1015,9 @@
There are two arguments: the first is a 4-byte little-endian signed int
giving the number of bytes in the string, and the second is that many
- bytes, which are taken literally as the string content.
+ bytes, which are taken literally as the string content. (Actually,
+ they are decoded into a str instance using the encoding given to the
+ Unpickler constructor. or the default, 'ASCII'.)
"""),
I(name='SHORT_BINSTRING',
@@ -1021,6 +1030,36 @@
There are two arguments: the first is a 1-byte unsigned int giving
the number of bytes in the string, and the second is that many bytes,
+ which are taken literally as the string content. (Actually, they
+ are decoded into a str instance using the encoding given to the
+ Unpickler constructor. or the default, 'ASCII'.)
+ """),
+
+ # Bytes (protocol 3 only; older protocols don't support bytes at all)
+
+ I(name='BINBYTES',
+ code='B',
+ arg=string4,
+ stack_before=[],
+ stack_after=[pybytes],
+ proto=3,
+ doc="""Push a Python bytes object.
+
+ There are two arguments: the first is a 4-byte little-endian signed int
+ giving the number of bytes in the string, and the second is that many
+ bytes, which are taken literally as the bytes content.
+ """),
+
+ I(name='SHORT_BINBYTES',
+ code='C',
+ arg=string1,
+ stack_before=[],
+ stack_after=[pybytes],
+ proto=1,
+ doc="""Push a Python string object.
+
+ There are two arguments: the first is a 1-byte unsigned int giving
+ the number of bytes in the string, and the second is that many bytes,
which are taken literally as the string content.
"""),
@@ -2006,9 +2045,9 @@
_dis_test = r"""
>>> import pickle
->>> x = [1, 2, (3, 4), {bytes(b'abc'): "def"}]
->>> pkl = pickle.dumps(x, 0)
->>> dis(pkl)
+>>> x = [1, 2, (3, 4), {b'abc': "def"}]
+>>> pkl0 = pickle.dumps(x, 0)
+>>> dis(pkl0)
0: ( MARK
1: l LIST (MARK at 0)
2: p PUT 0
@@ -2025,19 +2064,32 @@
25: ( MARK
26: d DICT (MARK at 25)
27: p PUT 2
- 30: S STRING 'abc'
- 37: p PUT 3
- 40: V UNICODE 'def'
- 45: p PUT 4
- 48: s SETITEM
- 49: a APPEND
- 50: . STOP
+ 30: c GLOBAL 'builtins bytes'
+ 46: p PUT 3
+ 49: ( MARK
+ 50: ( MARK
+ 51: l LIST (MARK at 50)
+ 52: p PUT 4
+ 55: L LONG 97
+ 59: a APPEND
+ 60: L LONG 98
+ 64: a APPEND
+ 65: L LONG 99
+ 69: a APPEND
+ 70: t TUPLE (MARK at 49)
+ 71: p PUT 5
+ 74: R REDUCE
+ 75: V UNICODE 'def'
+ 80: p PUT 6
+ 83: s SETITEM
+ 84: a APPEND
+ 85: . STOP
highest protocol among opcodes = 0
Try again with a "binary" pickle.
->>> pkl = pickle.dumps(x, 1)
->>> dis(pkl)
+>>> pkl1 = pickle.dumps(x, 1)
+>>> dis(pkl1)
0: ] EMPTY_LIST
1: q BINPUT 0
3: ( MARK
@@ -2050,13 +2102,24 @@
14: q BINPUT 1
16: } EMPTY_DICT
17: q BINPUT 2
- 19: U SHORT_BINSTRING 'abc'
- 24: q BINPUT 3
- 26: X BINUNICODE 'def'
- 34: q BINPUT 4
- 36: s SETITEM
- 37: e APPENDS (MARK at 3)
- 38: . STOP
+ 19: c GLOBAL 'builtins bytes'
+ 35: q BINPUT 3
+ 37: ( MARK
+ 38: ] EMPTY_LIST
+ 39: q BINPUT 4
+ 41: ( MARK
+ 42: K BININT1 97
+ 44: K BININT1 98
+ 46: K BININT1 99
+ 48: e APPENDS (MARK at 41)
+ 49: t TUPLE (MARK at 37)
+ 50: q BINPUT 5
+ 52: R REDUCE
+ 53: X BINUNICODE 'def'
+ 61: q BINPUT 6
+ 63: s SETITEM
+ 64: e APPENDS (MARK at 3)
+ 65: . STOP
highest protocol among opcodes = 1
Exercise the INST/OBJ/BUILD family.