. ? bytes .
>>> shell
1
>>> b = pickle.dumps(entry) ①
>>> type(b) ②
<class 'bytes'>
>>> entry3 = pickle.loads(b) ③
>>> entry3 == entry ④
True
① pickle.dumps() ( 's' ) pickle.dump(). ,
② pickle , pickle.dumps() bytes.
③ pickle.loads() ( 's' ) pickle.load(). , bytes , pickle.dumps()
④ : .
pickle , Python. pickle.
- Python 1.x , ( 0) ( 1)
- Python 2.3 pickle( 2) Python. .
- Python 3.0 pickle( 3) bytes . .
, . ( , .) , , Python 3 2, Python 2 3.
pickle
pickle? python entry.pickle, . .
you@localhost:~/diveintopython3/examples$ ls -l entry.pickle
-rw-r--r-- 1 you you 358 Aug 3 13:34 entry.pickle
you@localhost:~/diveintopython3/examples$ cat entry.pickle
comments_linkqNXtagsqXdiveintopythonqXdocbookqXhtmlq?qX publishedq?
XlinkXJhttp://diveintomark.org/archives/2009/03/27/dive-into-history-2009-edition
q Xpublished_dateq
ctime
struct_time
?qRqXtitleqXDive into history, 2009 editionqu.
. , ( ) . . , .
|
|
|
>>> shell
1
>>> import pickletools
>>> with open('entry.pickle', 'rb') as f:
... pickletools.dis(f)
0: \x80 PROTO 3
2: } EMPTY_DICT
3: q BINPUT 0
5: (MARK
6: X BINUNICODE 'published_date'
25: q BINPUT 1
27: c GLOBAL 'time struct_time'
45: q BINPUT 2
47: (MARK
48: M BININT2 2009
51: K BININT1 3
53: K BININT1 27
55: K BININT1 22
57: K BININT1 20
59: K BININT1 42
61: K BININT1 4
63: K BININT1 86
65: J BININT -1
70: t TUPLE (MARK at 47)
71: q BINPUT 3
73: } EMPTY_DICT
74: q BINPUT 4
76: \x86 TUPLE2
77: q BINPUT 5
79: R REDUCE
80: q BINPUT 6
82: X BINUNICODE 'comments_link'
100: q BINPUT 7
102: N NONE
103: X BINUNICODE 'internal_id'
119: q BINPUT 8
121: C SHORT_BINBYTES 'ÞÕ´ø'
127: q BINPUT 9
129: X BINUNICODE 'tags'
138: q BINPUT 10
140: X BINUNICODE 'diveintopython'
159: q BINPUT 11
161: X BINUNICODE 'docbook'
173: q BINPUT 12
175: X BINUNICODE 'html'
184: q BINPUT 13
186: \x87 TUPLE3
187: q BINPUT 14
189: X BINUNICODE 'title'
199: q BINPUT 15
201: X BINUNICODE 'Dive into history, 2009 edition'
237: q BINPUT 16
239: X BINUNICODE 'article_link'
256: q BINPUT 17
258: X BINUNICODE 'http://diveintomark.org/archives/2009/03/27/dive-into-history-2009-edition'
337: q BINPUT 18
339: X BINUNICODE 'published'
353: q BINPUT 19
355: \x88 NEWTRUE
356: u SETITEMS (MARK at 5)
357:. STOP
highest protocol among opcodes = 3
, , . pickle. Pickle, (opcodes) , Pickle. pickletools.dis() , . , , :
import pickletools
def protocol_version(file_object):
maxproto = -1
for opcode, arg, pos in pickletools.genops(file_object):
maxproto = max(maxproto, opcode.proto)
return maxproto
:
>>> import pickleversion
>>> with open('entry.pickle', 'rb') as f:
... v = pickleversion.protocol_version(f)
>>> v
3
