pickle\u6a21\u5757\u53ef\u4ee5\u5b58\u50a8\u54ea\u4e9b\u7c7b\u578b\uff1f<\/p>\n
\u6700\u540e\u4e00\u53e5\u5f88\u91cd\u8981\uff1a<\/p>\n \u5e8f\u5217\u5316\u7684\u7ed3\u679c\u53ef\u4ee5\u4e0d\u4fdd\u5b58\u5230\u6587\u4ef6\u4e2d\uff0c\u800c\u4fdd\u5b58\u5230\u5185\u5b58\u4e2d\u3002<\/p>\n pickle\u534f\u8bae\u5df2\u7ecf\u5f00\u53d1\u51fa\u6765\u5f88\u591a\u5e74\u4e86\uff0c\u5c31\u50cfpython\u672c\u8eab\u4e00\u6837\u6210\u719f\u3002\u8fd9\u91cc\u6709\u56db\u79cd\u4e0d\u540c\u7684pickle\u534f\u8bae\u7248\u672c\u3002<\/p>\n \u597d\u5427\uff01\u770b\u4e00\u4e0bbytes\u548cstrings\u4e4b\u524d\u7684\u4e0d\u540c\uff08\u539f\u6587\u6307\u51fa\u5982\u679c\u4e0d\u77e5\u9053\u7684\u8bdd\uff0c\u90a3\u8bf4\u660e\u6ca1\u4ed4\u7ec6\u770b\u4e4b\u524d\u7684\u5185\u5bb9\u3002\u3002\u3002\u597d\u5427\uff01\u7ffb\u8bd1\u4e86\u534a\u5929\u6211\u4e5f\u5fd8\u4e86\u4e4b\u524d\u600e\u4e48\u5199\u7684\u5566\uff01\u7b2c\u56db\u7ae0\u7b2c\u516d\u8282strings VS. BYTES\uff09\u3002<\/p>\n JSON\u662f\u57fa\u4e8e\u6587\u672c\u7684\uff0c\u5e76\u4e14\u5927\u5c0f\u5199\u654f\u611f\u3002\u56e0\u4e3a\u662f\u57fa\u4e8e\u6587\u672c\u7684\uff0c\u6240\u4ee5\u6709\u7a7a\u683c\u7684\u95ee\u9898\uff0c\u5728\u6bcf\u4e2a\u503c\u4e4b\u95f4\u53ef\u4ee5\u6709\u591a\u4e2a\u7a7a\u683c\uff0c\u5728\u7f16\u89e3\u7801\u65f6JSON\u4f1a\u5ffd\u7565\u8fd9\u4e9b\u503c\u4e4b\u95f4\u7684\u7a7a\u683c\u3002\u8fd9\u53ef\u4ee5\u8ba9\u4f60\u4ee5\u9002\u5f53\u7684\u7f29\u8fdb\u65b9\u5f0f\u5728\u663e\u793a\u5668\u4e0a\u663e\u793a\u6570\u636e\u6216\u6253\u5370\u51fa\u6765\u3002JSON\u5fc5\u987b\u4ee5UNICODE\u7f16\u7801\u5b58\u50a8\uff08UTF-32,UTF-16\u6216UTF-8\uff09\u3002<\/p>\n \u53ef\u4ee5\u4f7f\u7528JavaScript\u7684eval()\u51fd\u6570\u53bb\u201c\u89e3\u7801\u201dJSON\u5e8f\u5217\u5316\u6570\u636e\u3002<\/p>\n JSON\u5e8f\u5217\u5316\u540e\uff0c\u5b58\u50a8\u5728\u6587\u4ef6\u4e2d\u7684\u6570\u636e\u7ed3\u6784\u662f\u8fd9\u6837\u7684\uff1a<\/p>\n {“published”: true, “tags”: [“diveintopython”, “docbook”, “html”], “comments_link”: null, \u4e3a\u66f4\u597d\u7684\u53bb\u9605\u8bfb\u53ef\u4ee5\u5728dump()\u51fd\u6570\u4e2d\u52a0\u5165indent\u53c2\u6570\uff1a<\/strong><\/p>\n JSON\u548cPYTHON3\u6570\u636e\u7c7b\u578b\u7684\u5bf9\u5e94\u5173\u7cfb\uff1a<\/span><\/span><\/p>\n \u4f60\u6ce8\u610f\u5230\u5c11\u4e86\u4ec0\u4e48\u5417\uff1fTuples\u548cbytes\uff01JSON\u6709\u4e00\u4e2aarray\u7c7b\u578b\uff0c\u5b83\u5728json\u6a21\u5757\u4e2d\u6620\u8bbe\u5230python\u7684list\uff0c\u4f46\u662f\u6ca1\u6709\u5355\u72ec\u7684\u7c7b\u578b\u6620\u5c04\u5230tuples\u3002\u5e76\u4e14JSON\u5bf9\u5b57\u7b26\u4e32\u7684\u652f\u6301\u5341\u5206\u597d\uff0c\u6240\u4ee5\u4e5f\u6ca1\u6709\u5355\u72ec\u652f\u6301bytes\u5bf9\u8c61\u548cbyte\u6570\u7ec4\u3002<\/p>\n \u5e8f\u5217\u5316JSON\u4e0d\u652f\u6301\u7684\u6570\u636e\u7c7b\u578b\uff0c\u9700\u8981\u63d0\u4f9b\u7f16\u89e3\u7801\u4e60\u60ef\u3002<\/p>\n \u51fa\u9519\u7684\u539f\u56e0\u662fjson.dump()\u5e76\u4e0d\u652f\u6301bytes\u5bf9\u8c61\u7684\u5e8f\u5217\u5316\u3002\u5982\u679c\u4e00\u5b9a\u8981\u5b58\u50a8bytes\u5bf9\u8c61\uff0c\u5c31\u8981\u81ea\u5df1\u5b9a\u4e49\u5e8f\u5217\u5316\u683c\u5f0f\uff1a<\/p>\n \u8fd9\u5c31\u597d\u4e86\uff0c\u4e0d\u4f60\u9700\u8981\u518d\u505a\u4efb\u4f55\u5176\u5b83\u4e8b\u60c5\u3002\u4f60\u4e0d\u9700\u8981\u505a\u5168\u90e8\u7684\u5e8f\u5217\u5316\u5de5\u4f5c\uff0c\u4f60\u53ea\u9700\u8981\u8f6c\u6362\u6570\u636e\u7c7b\u578b\u5230JSON\u652f\u6301\u7684\u6570\u636e\u7c7b\u578b\u5c31\u53ef\u4ee5\u3002\u5269\u4e0b\u7684\u4e8b\u60c5json.dump()\u51fd\u6570\u4f1a\u53bb\u505a\u3002<\/p>\n \u518d\u6b21\u8fdb\u884c\u4fee\u6539\uff1a<\/p>\n \u8fd9\u65f6\u518d\u6b21\u6267\u884c\uff1a<\/p>\n \u5c31\u4e0d\u4f1a\u62a5\u4efb\u4f55\u9519\u8bef\u4e86\u3002<\/p>\n \u5c31\u50cfpickle\u6a21\u5757\u4e00\u6837\uff0cjson\u6a21\u5757\u540c\u6837\u4f7f\u7528load()\u51fd\u6570\u5e26\u4e00\u4e2a\u6d41\u5bf9\u8c61\u53c2\u6570\uff0c\u4ece\u4e2d\u8bfb\u53d6JSON\u683c\u5f0f\u5b57\u7b26\u4e32\u3002<\/p>\n \u8981\u60f3\u6062\u590d\u4e4b\u524d\u539f\u6765\u7684\u6570\u636e\u7ed3\u6784\uff0c\u8fd8\u8981\u5b9a\u4e49\u4e00\u4e2a\u4e0eto_json\u505a\u7528\u76f8\u53cd\u7684\u7a0b\u5e8f\u2014\u2014from_json<\/span>\uff1a<\/p>\n \u51c6\u5907\u5de5\u4f5c\u5b8c\u6210\uff0c\u8c03\u7528\u65b9\u6cd5\u5982\u4e0b\uff1a<\/p>\n \uff081\uff09pickle\u6a21\u5757 pickle\u6a21\u5757\u53ef\u4ee5\u5b58\u50a8\u54ea\u4e9b\u7c7b\u578b\uff1f python\u652f\u6301\u7684\u6240\u6709\u672c\u5730\u6570\u636e\u7c7b\u578b\uff1abooleans, intergers, floating po…<\/p>\n >>> entry = {} <\/code>
\n>>> entry['title'] = 'Dive into history, 2009 edition'<\/code>
\n>>> entry['article_link'] = 'http:\/\/diveintomark.org\/archives\/2009\/03\/27\/dive-into-history-2009-edition'<\/code>
\n>>> entry['comments_link'] = None<\/code>
\n>>> entry['internal_id'] = b'\\xDE\\xD5\\xB4\\xF8'<\/code>
\n>>> entry['tags'] = ('diveintopython', 'docbook', 'html')<\/code>
\n>>> entry['published'] = True<\/code>
\n>>> import time<\/code>
\n>>> entry['published_date'] = time.strptime('Fri Mar 27 22:20:42 2009') <\/code>
\n>>> entry['published_date']<\/code>
\ntime.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)<\/code><\/p>\n >>> import pickle\u00a0\u00a0\u00a0\u00a0\u00a0 \u2460<\/code>
\n>>> with open('entry.pickle', 'wb') as f: \u2461<\/code>
\n...\u00a0\u00a0\u00a0 pickle.dump(entry, f) \u2462<\/code><\/p>\n\n
\n
\uff083\uff09\u4ecepickle\u6587\u4ef6\u4e2d\u53d6\u56de\u6570\u636e<\/h2>\n
>>> import pickle<\/code>
\n>>> with open('entry.pickle', 'rb') as f: \u2460<\/code>
\n... \u00a0 \u00a0 entry = pickle.load(f)\u00a0\u00a0 \u2461<\/code>
\n...<\/code>
\n>>> entry <\/code>
\n{'comments_link': None,<\/code>
\n'internal_id': b'\\xDE\\xD5\\xB4\\xF8',<\/code>
\n'title': 'Dive into history, 2009 edition',<\/code>
\n'tags': ('diveintopython', 'docbook', 'html'),<\/code>
\n'article_link':<\/code>
\n'http:\/\/diveintomark.org\/archives\/2009\/03\/27\/dive-into-history-2009-edition',<\/code>
\n'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),<\/code>
\n'published': True}<\/code><\/p>\n\n
\uff084\uff09pickling without a file<\/h2>\n
>>> b = pickle.dumps(entry) \u2460<\/code>
\n>>> type(b) \u2461<\/code>
\n<class 'bytes'><\/code>
\n>>> entry3 = pickle.loads(b) \u2462<\/code>
\n>>> entry3 == entry \u2463<\/code>
\nTrue<\/code><\/p>\n\n
\uff085\uff09\u5f80\u4e8b\u5fc5\u987b\u518d\u6b21\u56de\u9996\u2014\u2014BYTES\u548cSTRINGS<\/h2>\n
\n
\uff086\uff09\u53ef\u4ee5\u8ba9\u5176\u5b83\u8bed\u8a00\u6253\u5f00python\u7684\u5e8f\u5217\u5316\u5bf9\u8c61\u2014\u2014JSON<\/h2>\n
>>> basic_entry = {} \u2460<\/code>
\n>>> basic_entry['id'] = 256<\/code>
\n>>> basic_entry['title'] = 'Dive into history, 2009 edition'<\/code>
\n>>> basic_entry['tags'] = ('diveintopython', 'docbook', 'html')<\/code>
\n>>> basic_entry['published'] = True<\/code>
\n>>> basic_entry['comments_link'] = None<\/code>
\n>>> import json<\/strong><\/code>
\n>>> with open('basic.json', mode='w', encoding='utf-8') as f: \u2461<\/code>
\n...\u00a0\u00a0\u00a0\u00a0 json.dump(basic_entry, f)\u00a0\u00a0 \u2462<\/code><\/p>\n\n
\n“id”: 256, “title”: “Dive into history, 2009 edition”}<\/p>\n >>> with open('basic-pretty.json', mode='w', encoding='utf-8') as f:<\/code>
\n...\u00a0\u00a0\u00a0\u00a0 json.dump(basic_entry, f, indent=2)<\/code><\/p>\n\n
{<\/code>
\n\u00a0 \"published\": true,<\/code>
\n\u00a0 \"tags\": [<\/code>
\n\u00a0\u00a0\u00a0 \"diveintopython\",<\/code>
\n\u00a0\u00a0\u00a0 \"docbook\",<\/code>
\n\u00a0\u00a0\u00a0 \"html\"<\/code>
\n\u00a0 ],<\/code>
\n\u00a0 \"comments_link\": null,<\/code>
\n\u00a0 \"id\": 256,<\/code>
\n\u00a0 \"title\": \"Dive into history, 2009 edition\"<\/code>
\n}<\/code><\/p>\n\n\n
\n \u6ce8\u610f<\/th>\n JSON<\/th>\n Python3<\/th>\n<\/tr>\n \n <\/th>\n object<\/th>\n directory<\/th>\n<\/tr>\n \n <\/th>\n array<\/th>\n list<\/th>\n<\/tr>\n \n <\/th>\n string<\/th>\n string<\/th>\n<\/tr>\n \n <\/th>\n integer<\/th>\n integer<\/th>\n<\/tr>\n \n <\/th>\n \u5b9e\u9645\u6570\u5b57<\/th>\n float<\/th>\n<\/tr>\n \n *<\/th>\n true<\/th>\n True<\/th>\n<\/tr>\n \n *<\/th>\n false<\/th>\n False<\/th>\n<\/tr>\n \n *<\/th>\n null<\/th>\n None<\/th>\n<\/tr>\n \n *\u8868\u793a\u6240\u6709JSON\u503c\u662f\u5927\u5c0f\u5199\u654f\u611f\u7684<\/th>\n<\/tr>\n<\/tbody>\n<\/table>\n \uff087\uff09\u5e8f\u5217\u5316JSON\u4e0d\u652f\u6301\u7684\u6570\u636e\u7c7b\u578b<\/h2>\n
>>> entry \u2460<\/code>
\n{'comments_link': None,<\/code>
\n'internal_id': b'\\xDE\\xD5\\xB4\\xF8',<\/code>
\n'title': 'Dive into history, 2009 edition',<\/code>
\n'tags': ('diveintopython', 'docbook', 'html'),<\/code>
\n'article_link': 'http:\/\/diveintomark.org\/archives\/2009\/03\/27\/dive-into-history-2009-edition',<\/code>
\n'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),<\/code>
\n'published': True}<\/code>
\n>>> import json<\/code>
\n>>> with open('entry.json', 'w', encoding='utf-8') as f: \u2461<\/code>
\n...\u00a0\u00a0\u00a0\u00a0 json.dump(entry, f) \u2462<\/code>
\n...<\/code>
\nTraceback (most recent call last):<\/code><\/span>
\nFile \"<stdin>\", line 5, in <module><\/code><\/span>
\nFile \"C:\\Python31\\lib\\json\\__init__.py\", line 178, in dump<\/code><\/span>
\nfor chunk in iterable:<\/code><\/span>
\nFile \"C:\\Python31\\lib\\json\\encoder.py\", line 408, in _iterencode<\/code><\/span>
\nfor chunk in _iterencode_dict(o, _current_indent_level):<\/code><\/span>
\nFile \"C:\\Python31\\lib\\json\\encoder.py\", line 382, in _iterencode_dict<\/code><\/span>
\nfor chunk in chunks:<\/code><\/span>
\nFile \"C:\\Python31\\lib\\json\\encoder.py\", line 416, in _iterencode<\/code><\/span>
\no = _default(o)<\/code><\/span>
\nFile \"C:\\Python31\\lib\\json\\encoder.py\", line 170, in default<\/code><\/span>
\nraise TypeError(repr(o) + \" is not JSON serializable\")<\/code><\/span>
\nTypeError: b'\\xDE\\xD5\\xB4\\xF8' is not JSON serializable<\/code><\/span><\/span><\/p>\n\n
TypeError: b'\\xDE\\xD5\\xB4\\xF8' is not JSON serializable<\/code><\/span><\/span><\/li>\n<\/ol>\n def to_json(python_object): \u2460<\/code>
\n\u00a0\u00a0\u00a0 if isinstance(python_object, bytes): \u2461<\/code>
\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 return {'__class__': 'bytes', <\/code>'__value__': list(python_object)} \u2462<\/code>
\n\u00a0\u00a0\u00a0 raise TypeError(repr(python_object) + ' is not JSON serializable') \u2463<\/code><\/p>\n\n
b'\\xDE\\xD5\\xB4\\xF8'<\/code><\/span><\/span>\u4f1a\u901a\u8fc7list()\u8f6c\u6362\u6210\u4e00\u4e2a\u5217\u8868 [222, 213, 180, 248]<\/span>\u3002\uff08\u5341\u516d\u8fdb\u5236\\xDE\u662f\u5341\u8fdb\u5236\u7684222\uff09<\/li>\n >>> import customserializer \u2460<\/code>
\n>>> with open('entry.json', 'w', encoding='utf-8') as f: \u2461<\/code>
\n...\u00a0\u00a0\u00a0\u00a0 json.dump(entry, f,default=customserializer.to_json) \u2462<\/code>
\n...<\/code>
\nTraceback (most recent call last):<\/code>
\nFile \"<stdin>\", line 9, in <module><\/code>
\njson.dump(entry, f, default=customserializer.to_json)<\/code>
\nFile \"C:\\Python31\\lib\\json\\__init__.py\", line 178, in dump<\/code>
\nfor chunk in iterable:<\/code>
\nFile \"C:\\Python31\\lib\\json\\encoder.py\", line 408, in _iterencode<\/code>
\nfor chunk in _iterencode_dict(o, _current_indent_level):<\/code>
\nFile \"C:\\Python31\\lib\\json\\encoder.py\", line 382, in _iterencode_dict<\/code>
\nfor chunk in chunks:<\/code>
\nFile \"C:\\Python31\\lib\\json\\encoder.py\", line 416, in _iterencode<\/code>
\no = _default(o)<\/code>
\nFile \"\/Users\/pilgrim\/diveintopython3\/examples\/customserializer.py\", line 12, in to_json<\/code>
\nraise TypeError(repr(python_object) + ' is not JSON serializable') \u2463<\/code>
\nTypeError: 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<\/code><\/span><\/span><\/p>\n\n
customserializer<\/code>\u6a21\u5757\u5c31\u662f\u521a\u521a\u5b9a\u4e49\u7684to_json()<\/code>\u6240\u5728\u7684\u6a21\u5757\u3002<\/li>\n import time<\/code>
\ndef to_json(python_object):<\/code>
\n\u00a0\u00a0\u00a0 if isinstance(python_object, time.struct_time): \u2460<\/code>
\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 return {'__class__': 'time.asctime', <\/code>'__value__': time.asctime(python_object)} \u2461<\/code>
\n\u00a0\u00a0\u00a0 if isinstance(python_object, bytes):<\/code>
\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 return {'__class__': 'bytes', <\/code>'__value__': list(python_object)}<\/code>
\n\u00a0\u00a0\u00a0 raise TypeError(repr(python_object) + ' is not JSON serializable')<\/code><\/p>\n\n
customserializer.to_json()<\/code>\u51fd\u6570\u4e2d\uff0c\u5e76\u68c0\u67e5python_object\u7684\u7c7b\u578b\u662f\u5426\u4e3atime.struct_time<\/code>\u3002<\/li>\ntime.struct_time<\/code>\u5bf9\u8c61\u5230\u4e2a\u53ef\u4ee5\u88abjson\u5e8f\u5217\u5316\u7684\u7c7b\u578b\u3002\u672c\u4f8b\u4e2dtime.asctime()<\/code>\u51fd\u6570\u8f6c\u6362time.struct_time<\/code>\u7ed3\u6784\u5230string<\/code>\u7c7b\u578b” Fri Mar 27 22:20:42 2009″<\/li>\n<\/ol>\n >>> with open('entry.json', 'w', encoding='utf-8') as f:<\/code>
\n...\u00a0\u00a0\u00a0\u00a0 json.dump(entry, f,default=customserializer.to_json)<\/code><\/p>\n\uff088\uff09\u4ece\u6587\u4ef6\u4e2d\u6062\u590dJSON\u6570\u636e<\/h2>\n
>>> import json<\/code>
\n>>> with open('entry.json', 'r', encoding='utf-8') as f:<\/code>
\n...\u00a0\u00a0\u00a0\u00a0 entry = json.load(f)\u00a0 \u2460<\/code>
\n...<\/code>
\n>>> entry\u00a0\u00a0\u00a0\u00a0 \u2461<\/code>
\n{'comments_link': None,<\/code>
\n'internal_id': {'__class__': 'bytes', '__value__': [222, 213, 180, 248]},<\/code>
\n'title': 'Dive into history, 2009 edition',<\/code>
\n'tags': ['diveintopython', 'docbook', 'html'],<\/code>
\n'article_link': 'http:\/\/diveintomark.org\/archives\/2009\/03\/27\/dive-into-history-2009-edition',<\/code>
\n'published_date': {'__class__': 'time.asctime', '__value__': 'Fri Mar 27 22:20:42 2009'},<\/code>
\n'published': True}<\/code><\/p>\n\n
def from_json(json_object): \u2460<\/code>
\n\u00a0\u00a0\u00a0 if '__class__' in json_object: \u2461<\/code>
\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 if json_object['__class__'] == 'time.asctime':<\/code>
\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 return time.strptime(json_object['__value__']) \u2462<\/code>
\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 if json_object['__class__'] == 'bytes':<\/code>
\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 return bytes(json_object['__value__']) \u2463<\/code>
\n\u00a0\u00a0\u00a0 return json_object<\/code><\/p>\n\n
>>> import customserializer<\/code>
\n>>> with open('entry.json', 'r', encoding='utf-8') as f:<\/code>
\n... \u00a0 \u00a0 entry = json.load(f, object_hook=customserializer.from_json) \u2460<\/code>
\n...<\/code>
\n>>> entry \u00a0 \u2461<\/code>
\n{'comments_link': None,<\/code>
\n'internal_id': b'\\xDE\\xD5\\xB4\\xF8',<\/code>
\n'title': 'Dive into history, 2009 edition',<\/code>
\n'tags': ['diveintopython', 'docbook', 'html'],<\/code>
\n'article_link': 'http:\/\/diveintomark.org\/archives\/2009\/03\/27\/dive-into-history-2009-edition',<\/code>
\n'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),<\/code>
\n'published': True}<\/code><\/p>\n\n
from_json()<\/code>\u51fd\u6570\u6302\u8f7d\uff08hook\uff09\u5230load()<\/code>\u4e0a\uff0cobject_hook<\/code>\u53c2\u6570\u662f\u4f20\u9012\u7ed9json.load()<\/code>\u51fd\u6570\u7684\u3002<\/li>\n