JSON bytes, bytes. json . ( "" " json". , json , json). bytes , json , .
>>> shell
1
>>> entry ①
{'comments_link': None,
'internal_id': b'\xDE\xD5\xB4\xF8',
'title': 'Dive into history, 2009 edition',
'tags': ('diveintopython', 'docbook', 'html'),
'article_link': 'http://diveintomark.org/archives/2009/03/27/dive-into-history-2009-edition',
'published_date': time.struct_time(tm_year=2009, tm_mon=3, tm_mday=27, tm_hour=22, tm_min=20, tm_sec=42, tm_wday=4, tm_yday=86, tm_isdst=-1),
'published': True}
>>> import json
>>> with open('entry.json', 'w', encoding='utf-8') as f: ②
... json.dump(entry, f) ③
...
Traceback (most recent call last):
File "<stdin>", line 5, in <module>
File "C:\Python31\lib\json\__init__.py", line 178, in dump
for chunk in iterable:
File "C:\Python31\lib\json\encoder.py", line 408, in _iterencode
for chunk in _iterencode_dict(o, _current_indent_level):
File "C:\Python31\lib\json\encoder.py", line 382, in _iterencode_dict
for chunk in chunks:
File "C:\Python31\lib\json\encoder.py", line 416, in _iterencode
o = _default(o)
File "C:\Python31\lib\json\encoder.py", line 170, in default
raise TypeError(repr(o) + " is not JSON serializable")
TypeError: b'\xDE\xD5\xB4\xF8' is not JSON serializable
① , entry. : , , , , bytes, .
② , , : json . json utf-8.
③... __ . ?
: json.dump() bytes b'\xDE\xD5\xB4\xF8', , json bytes. , , " ".
def to_json(python_object): ①
if isinstance(python_object, bytes): ②
return {'__class__': 'bytes',
'__value__': list(python_object)} ③
raise TypeError(repr(python_object) + ' is not JSON serializable') ④
① " " , json , , Python . Python , json.dump() - bytes b'\xDE\xD5\xB4\xF8'
|
|
|
② Python, json.dump(). , , , ,
③ bytes . __class__ , __value__ . , bytes, - json. bytes , - 0 255. list() bytes . b'\xDE\xD5\xB4\xF8' [222, 213, 180, 248]. (! ! \xDE 222 , \xD5 213, .)
④ . , json, . , raise TypeError json.dump() , .
, . , Python, . json , ----. json.dump() .
>>> shell
1
>>> import customserializer ①
>>> with open('entry.json', 'w', encoding='utf-8') as f: ②
... json.dump(entry, f, default=customserializer.to_json) ③
...
Traceback (most recent call last):
File "<stdin>", line 9, in <module>
json.dump(entry, f, default=customserializer.to_json)
File "C:\Python31\lib\json\__init__.py", line 178, in dump
for chunk in iterable:
File "C:\Python31\lib\json\encoder.py", line 408, in _iterencode
for chunk in _iterencode_dict(o, _current_indent_level):
File "C:\Python31\lib\json\encoder.py", line 382, in _iterencode_dict
for chunk in chunks:
File "C:\Python31\lib\json\encoder.py", line 416, in _iterencode
o = _default(o)
File "/Users/pilgrim/diveintopython3/examples/customserializer.py", line 12, in to_json
raise TypeError(repr(python_object) + ' is not JSON serializable') ④
TypeError: time.struct_time(tm_year=2009, tm_mon=3, tm_mday=27, tm_hour=22, tm_min=20, tm_sec=42, tm_wday=4, tm_yday=86, tm_isdst=-1) is not JSON serializable
① customserializer, to_json()
② , utf-8, --. ( ! ! , , )
③ : json.dump() json.dump() default. (, Python - !)
④ , . . json.dump() , bytes. : time.struct_time.
|
|
|
, . , .
import time
def to_json(python_object):
if isinstance(python_object, time.struct_time): ①
return {'__class__': 'time.asctime',
'__value__': time.asctime(python_object)} ②
if isinstance(python_object, bytes):
return {'__class__': 'bytes',
'__value__': list(python_object)}
raise TypeError(repr(python_object) + ' is not JSON serializable')
① customserializer.to_json() , Python( json.dump() ) time.struct_time.
② , , bytes: time.struct_time json. , json time.asctime(). time.asctime() time.struct_time 'Fri Mar 27 22:20:42 2009'.
, entry .
>>> shell
1
>>> with open('entry.json', 'w', encoding='utf-8') as f:
... json.dump(entry, f, default=customserializer.to_json)
...
you@localhost:~/diveintopython3/examples$ ls -l example.json
-rw-r--r-- 1 you you 391 Aug 3 13:34 entry.json
you@localhost:~/diveintopython3/examples$ cat example.json
{"published_date": {"__class__": "time.asctime", "__value__": "Fri Mar 27 22:20:42 2009"},
"comments_link": null, "internal_id": {"__class__": "bytes", "__value__": [222, 213, 180, 248]},
"tags": ["diveintopython", "docbook", "html"], "title": "Dive into history, 2009 edition",
"article_link": "http://diveintomark.org/archives/2009/03/27/dive-into-history-2009-edition",
"published": true}
