{"id":208,"date":"2023-10-26T16:38:30","date_gmt":"2023-10-26T08:38:30","guid":{"rendered":"http:\/\/ai.gitpp.com\/?p=208"},"modified":"2023-10-27T09:38:38","modified_gmt":"2023-10-27T01:38:38","slug":"11-%e6%a0%87%e5%87%86%e5%ba%93%e7%9a%84%e7%ae%80%e6%98%8e%e4%bb%8b%e7%bb%8d%ef%bc%88%e7%ac%ac%e4%ba%8c%e9%83%a8%e5%88%86%ef%bc%89","status":"publish","type":"post","link":"http:\/\/ai.gitpp.com\/index.php\/2023\/10\/26\/11-%e6%a0%87%e5%87%86%e5%ba%93%e7%9a%84%e7%ae%80%e6%98%8e%e4%bb%8b%e7%bb%8d%ef%bc%88%e7%ac%ac%e4%ba%8c%e9%83%a8%e5%88%86%ef%bc%89\/","title":{"rendered":"\u300aPython\u5165\u95e8\u6559\u7a0b\u300b11. \u6807\u51c6\u5e93\u7684\u7b80\u660e\u4ecb\u7ecd\uff08\u7b2c\u4e8c\u90e8\u5206\uff09"},"content":{"rendered":"\n
    \n
  1. \u5f00\u80c3\u83dc<\/li>\n\n\n\n
  2. \u4f7f\u7528 Python \u89e3\u91ca\u5668<\/a><\/li>\n\n\n\n
  3. \u975e\u6b63\u5f0f\u4ecb\u7ecdPython<\/a><\/li>\n\n\n\n
  4. \u6df1\u5165\u6d41\u7a0b\u63a7\u5236<\/a><\/li>\n\n\n\n
  5. \u6570\u636e\u7ed3\u6784<\/a><\/li>\n\n\n\n
  6. \u6a21\u5757<\/a><\/li>\n\n\n\n
  7. \u8f93\u5165\u548c\u8f93\u51fa<\/a><\/li>\n\n\n\n
  8. \u9519\u8bef\u548c\u5f02\u5e38<\/a><\/li>\n\n\n\n
  9. \u7c7b<\/a><\/li>\n\n\n\n
  10. \u6807\u51c6\u5e93\u7684\u7b80\u660e\u4ecb\u7ecd<\/a><\/li>\n\n\n\n
  11. \u6807\u51c6\u5e93\u7684\u7b80\u660e\u4ecb\u7ecd\uff08\u7b2c\u4e8c\u90e8\u5206\uff09<\/a><\/li>\n\n\n\n
  12. \u73b0\u5728\u5e72\u4ec0\u4e48?<\/a><\/li>\n\n\n\n
  13. \u4ea4\u4e92\u5f0f\u8f93\u5165\u7f16\u8f91\u53ca\u5386\u53f2\u66ff\u4ee3<\/a><\/li>\n\n\n\n
  14. \u6d6e\u70b9\u7b97\u672f: \u95ee\u9898\u548c\u9650\u5236<\/a><\/li>\n<\/ol>\n\n\n\n

    \u7b2c\u4e8c\u90e8\u5206\u6db5\u76d6\u4e86\u8bb8\u591a\u5173\u4e8e\u4e13\u4e1a\u7f16\u7a0b\u9700\u6c42\u7684\u9ad8\u7ea7\u6a21\u5757. \u8fd9\u4e9b\u6a21\u5757\u5f88\u5c11\u51fa\u73b0\u5728\u5c0f\u7684\u7a0b\u5e8f\u5f53\u4e2d.<\/p>\n\n\n\n

    11.1. \u683c\u5f0f\u5316\u8f93\u51fa<\/a><\/h2>\n\n\n\n

    reprlib<\/code><\/a> \u6a21\u5757\u63d0\u4f9b\u4e86\u4e00\u4e2a\u9762\u5411\u5185\u5bb9\u5f88\u591a\u6216\u8005\u6df1\u5ea6\u5f88\u5e7f\u7684\u5d4c\u5957\u5bb9\u5668\u7684\u81ea\u5b9a\u4e49\u7248\u672c repr()<\/code><\/a>, \u5b83\u53ea\u663e\u793a\u7f29\u7565\u56fe>>> <\/strong>import<\/strong>reprlib<\/strong>>>> <\/strong>reprlib.repr(set(‘supercalifragilisticexpialidocious’)) “set([‘a’, ‘c’, ‘d’, ‘e’, ‘f’, ‘g’, …])”<\/p>\n\n\n\n

    pprint<\/code><\/a> \u6a21\u5757\u901a\u8fc7\u4e00\u79cd\u80fd\u591f\u8ba9\u89e3\u91ca\u5668\u8bfb\u61c2\u7684\u65b9\u6cd5, \u6765\u5bf9\u5185\u7f6e\u7684\u548c\u7528\u6237\u81ea\u5b9a\u4e49\u7684\u4e00\u4e9b\u5bf9\u8c61\u7684\u8f93\u51fa\u8fdb\u884c \u66f4\u590d\u6742\u7684\u64cd\u4f5c. \u5f53\u8fd4\u56de\u7684\u7ed3\u679c\u5927\u4e8e\u4e00\u884c\u65f6, \u201cpretty printer\u201d \u529f\u80fd\u6a21\u5757\u4f1a\u52a0\u4e0a\u65ad\u884c\u7b26\u548c\u9002\u5f53\u7684\u7f29\u8fdb, \u4ee5 \u4f7f\u6570\u636e\u7684\u7ed3\u6784\u66f4\u52a0\u6e05\u6670\u660e\u6717:>>> <\/strong>import<\/strong>pprint<\/strong>>>> <\/strong>t = [[[[‘black’, ‘cyan’], ‘white’, [‘green’, ‘red’]], [[‘magenta’, …<\/strong> ‘yellow’], ‘blue’]]] …<\/strong>>>> <\/strong>pprint.pprint(t, width=30) [[[[‘black’, ‘cyan’], ‘white’, [‘green’, ‘red’]], [[‘magenta’, ‘yellow’], ‘blue’]]]<\/p>\n\n\n\n

    textwrap<\/code><\/a> \u6a21\u5757\u4f1a\u6839\u636e\u5c4f\u5e55\u7684\u5bbd\u5ea6\u800c\u9002\u5f53\u5730\u53bb\u8c03\u6574\u6587\u672c\u6bb5\u843d:>>> <\/strong>import<\/strong>textwrap<\/strong>>>> <\/strong>doc = “””The wrap() method is just like fill() except that it returns … <\/strong>a list of strings instead of one big string with newlines to separate … <\/strong>the wrapped lines.””” …<\/strong>>>> <\/strong>print(textwrap.fill(doc, width=40)) The wrap() method is just like fill() except that it returns a list of strings instead of one big string with newlines to separate the wrapped lines.<\/p>\n\n\n\n

    locale<\/code><\/a> \u6a21\u5757\u8bbf\u95ee\u4e00\u4e2a\u5305\u542b\u56e0\u7279\u5b9a\u8bed\u8a00\u73af\u5883\u800c\u5f02\u7684\u6570\u636e\u683c\u5f0f\u7684\u6570\u636e\u5e93. locale\u6a21\u5757\u7684\u683c\u5f0f\u5316\u51fd\u6570\u7684\u5206\u7ec4\u5c5e\u6027, \u53ef\u4ee5\u7528\u7ec4\u522b\u5206\u79bb\u5668, \u76f4\u63a5\u5730\u53bb\u683c\u5f0f\u5316\u6570\u5b57:>>> <\/strong>import<\/strong>locale<\/strong>>>> <\/strong>locale.setlocale(locale.LC_ALL, ‘English_United States.1252’) ‘English_United States.1252’ >>> <\/strong>conv = locale.localeconv() # \u5f97\u5230\u4e00\u4e2a\u5e38\u89c4\u6846\u67b6\u7684\u6620\u5c04<\/em>>>> <\/strong>x = 1234567.8 >>> <\/strong>locale.format(“%d<\/em>“, x, grouping=True<\/strong>) ‘1,234,567’ >>> <\/strong>locale.format_string(“%s%.*f<\/em>“, (conv[‘currency_symbol’], …<\/strong> conv[‘frac_digits’], x), grouping=True<\/strong>) ‘$1,234,567.80’<\/p>\n\n\n\n

    11.2. \u6a21\u677f\u5316<\/a><\/h2>\n\n\n\n

    string<\/code><\/a> \u6a21\u5757\u5305\u62ec\u4e00\u4e2a\u591a\u5143\u5316\u7684 Template<\/code> \u7c7b, \u4e3a\u7528\u6237\u63d0\u4f9b\u7b80\u5316\u4e86\u7684\u8bed\u6cd5\u683c\u5f0f, \u4f7f\u5176\u53ef\u4ee5\u65b9\u4fbf\u7684\u7f16\u8f91. \u8fd9\u6837\u53ef\u4ee5\u4f7f\u7528\u6237\u81ea\u5b9a\u4e49\u81ea\u5df1\u7684\u7a0b\u5e8f\u800c\u4e0d\u7528\u53bb\u4fee\u6539\u7a0b\u5e8f\u672c\u8eab.<\/p>\n\n\n\n

    \u8fd9\u79cd\u683c\u5f0f\u4f7f\u7528\u7531 $<\/code> \u548c\u5408\u6cd5\u7684Python\u6807\u8bc6\uff08\u5305\u62ec\u6587\u5b57\u3001\u6570\u5b57\u548c\u4e0b\u5212\u7ebf\uff09\u7ec4\u6210\u7684\u5360\u4f4d\u7b26\u540d\u79f0. \u5c06\u8fd9\u4e9b\u5360\u4f4d\u7b26 \u5305\u542b\u5728\u4e00\u5bf9\u82b1\u62ec\u53f7\u91cc\u65f6\u5141\u8bb8\u5468\u56f4\u5b58\u5728\u66f4\u591a\u7684\u5b57\u6bcd\u6216\u8005\u6570\u5b57\u800c\u4e0d\u7528\u7406\u4f1a\u662f\u5426\u6709\u7a7a\u683c. \u5fc5\u8981\u65f6\u4f7f\u7528 $$<\/code> \u53bb\u8868\u793a \u5355\u72ec\u7684 $<\/code>>>> <\/strong>from<\/strong>string<\/strong>import<\/strong> Template >>> <\/strong>t = Template(‘${village}<\/em>folk send $$10 to $cause.’) >>> <\/strong>t.substitute(village=’Nottingham’, cause=’the ditch fund’) ‘Nottinghamfolk send $10 to the ditch fund.’<\/p>\n\n\n\n

    \u5f53\u4e00\u4e2a\u5b57\u5178\u6216\u8005\u5173\u952e\u5b57\u53c2\u6570\u6ca1\u6709\u7ed9\u5360\u4f4d\u7b26\u63d0\u4f9b\u76f8\u5e94\u7684\u503c\u65f6, substitute()<\/code> \u65b9\u6cd5\u4f1a\u629b\u51fa\u4e00\u4e2a KeyError<\/code><\/a> \u5f02\u5e38. \u5bf9\u4e8e\u50cfmail-merge\u98ce\u683c\u7684\u5e94\u7528\u7a0b\u5e8f, \u7528\u6237\u53ef\u80fd\u4f1a\u63d0\u4f9b\u4e0d\u5b8c\u6574\u7684\u6570\u636e, \u6b64\u65f6, safe_substitute()<\/code> \u65b9\u6cd5\u53ef\u80fd\u4f1a\u66f4\u9002\u5408\u2014\u2014\u5f53\u6570\u636e\u7f3a\u5931\u7684\u65f6\u5019, \u5b83\u4e0d\u4f1a\u6539\u53d8\u5360\u4f4d\u7b26:>>> <\/strong>t = Template(‘Return the $item to $owner.’) >>> <\/strong>d = dict(item=’unladen swallow’) >>> <\/strong>t.substitute(d) Traceback (most recent call last): . . . KeyError: ‘owner’ >>> <\/strong>t.safe_substitute(d) ‘Return the unladen swallow to $owner.’<\/p>\n\n\n\n

    Template\u7c7b\u7684\u5b50\u7c7b\u53ef\u4ee5\u6307\u5b9a\u4e00\u4e2a\u81ea\u5df1\u7684\u5206\u9694\u7b26. \u4f8b\u5982, \u73b0\u5728\u6709\u4e00\u5927\u6279\u6587\u4ef6\u7684\u91cd\u547d\u540d\u5de5\u4f5c, \u9488\u5bf9\u7684\u662f\u4e00\u4e2a\u7167 \u7247\u6d4f\u89c8\u5668, \u5b83\u53ef\u80fd\u4f1a\u9009\u62e9\u4f7f\u7528\u767e\u5206\u7b26\u53f7\u5c06\u5f53\u524d\u65f6\u95f4\u3001\u56fe\u7247\u7684\u5e8f\u5217\u53f7\u6216\u8005\u6587\u4ef6\u683c\u5f0f\u5206\u9694\u51fa\u6765\u4f5c\u4e3a\u5360\u4f4d\u7b26:>>> <\/strong>import<\/strong>time<\/strong>, os.path<\/strong>>>> <\/strong>photofiles = [‘img_1074.jpg’, ‘img_1076.jpg’, ‘img_1077.jpg’] >>> <\/strong>class<\/strong>BatchRename<\/strong>(Template): …<\/strong> delimiter = ‘%’ >>> <\/strong>fmt = input(‘Enter rename style (%d<\/em>-date %n-seqnum %f<\/em>-format): ‘) Enter rename style (%d-date %n-seqnum %f-format): Ashley_%n%f >>> <\/strong>t = BatchRename(fmt) >>> <\/strong>date = time.strftime(‘%d<\/em>%b%y’) >>> <\/strong>for<\/strong> i, filename in<\/strong> enumerate(photofiles): …<\/strong> base, ext = os.path.splitext(filename) …<\/strong> newname = t.substitute(d=date, n=i, f=ext) …<\/strong> print(‘{0}<\/em> –> {1}<\/em>‘.format(filename, newname)) img_1074.jpg –> Ashley_0.jpg img_1076.jpg –> Ashley_1.jpg img_1077.jpg –> Ashley_2.jpg<\/p>\n\n\n\n

    \u53e6\u4e00\u4e2a\u7528\u4e8e\u6a21\u677f\u5316\u7684\u5e94\u7528\u7a0b\u5e8f\u662f\u5c06\u9879\u76ee\u7684\u903b\u8f91\u6309\u591a\u79cd\u8f93\u51fa\u683c\u5f0f\u7684\u7ec6\u8282\u5206\u79bb\u5f00\u6765. \u8fd9\u4f7f\u5f97\u4ece\u4f20\u7edf\u7684\u6a21\u677f\u5f62\u5f0f\u8f6c\u5316 \u4e3aXML\u6587\u4ef6\u3001\u7eaf\u6587\u672c\u5f62\u5f0f\u548chtml\u7f51\u9875\u6210\u4e3a\u4e86\u53ef\u80fd.<\/p>\n\n\n\n

    11.3. Working with Binary Data Record Layouts<\/a><\/h2>\n\n\n\n

    struct<\/code><\/a> \u6a21\u5757\u4e00\u4e9b\u51fd\u6570, \u5982 :fun:`pack`<\/a> \u548c :fun:`unpack`<\/a> \u51fd\u6570\u53bb\u5904\u7406\u957f\u5ea6\u53ef\u53d8\u7684\u4e8c\u8fdb\u5236 \u8bb0\u5f55\u683c\u5f0f. \u4e0b\u9762\u8fd9\u4e2a\u4f8b\u5b50\u6f14\u793a\u4e86\u5982\u4f55\u5728\u4e0d\u4f7f\u7528 zipfile<\/code><\/a> \u6a21\u5757\u7684\u60c5\u51b5\u4e0b\u53bb\u5faa\u73af\u5f97\u5230\u4e00\u4e2aZIP\u6587\u4ef6\u7684 \u6807\u9898\u4fe1\u606f. \u5305\u4ee3\u7801 H<\/code> \u548c I<\/code> \u5206\u522b\u8868\u793a\u4e24\u4e2a\u548c\u56db\u4e2a\u5b57\u8282\u7684\u65e0\u7b26\u53f7\u6570\u5b57. \u800c <<\/code> \u5219\u8868\u793a\u5b83\u4eec\u662f\u6807\u51c6 \u5927\u5c0f\u5e76\u4ee5\u5b57\u8282\u5927\u5c0f\u7684\u987a\u5e8f\u6392\u5217\u5728\u540e\u9762:import<\/strong>struct<\/strong> data = open(‘myfile.zip’, ‘rb’).read() start = 0 for<\/strong> i in<\/strong> range(3): # \u663e\u793a\u6700\u5f00\u59cb\u76843\u4e2a\u6807\u9898<\/em> start += 14 fields = struct.unpack(‘<IIIHH’, data[start:start+16]) crc32, comp_size, uncomp_size, filenamesize, extra_size = fields start += 16 filename = data[start:start+filenamesize] start += filenamesize extra = data[start:start+extra_size] print(filename, hex(crc32), comp_size, uncomp_size) start += extra_size + comp_size # \u8df3\u5230\u53e6\u4e00\u4e2a\u6807\u9898<\/em><\/p>\n\n\n\n

    11.4. \u591a\u7ebf\u7a0b<\/a><\/h2>\n\n\n\n

    \u7ebf\u7a0b\u662f\u4e00\u79cd\u4f7f\u6ca1\u6709\u987a\u5e8f\u5173\u7cfb\u7684\u4efb\u52a1\u5e76\u53d1\u6267\u884c\u7684\u6280\u672f. \u7ebf\u7a0b\u53ef\u4ee5\u7528\u6765\u6539\u8fdb\u5e94\u7528\u7a0b\u5e8f\u7684\u54cd\u5e94\u65b9\u5f0f\u4f7f\u8fd9\u4e9b\u7a0b\u5e8f\u53ef \u5728\u63a5\u53d7\u7528\u6237\u8f93\u5165\u7684\u540c\u65f6\u5728\u540e\u53f0\u6267\u884c\u53e6\u4e00\u4e9b\u64cd\u4f5c. \u4e00\u4e2a\u4e0e\u6b64\u76f8\u5173\u7684\u4f8b\u5b50\u662f\u8fd0\u884c\u8f93\u5165\u8f93\u51fa\u7a0b\u5e8f\u7684\u540c\u65f6\u5728\u53e6\u4e00\u4e2a \u7ebf\u7a0b\u5e8f\u4e2d\u6267\u884c\u8ba1\u7b97\u64cd\u4f5c.<\/p>\n\n\n\n

    \u4e0b\u9762\u7684\u4ee3\u7801\u663e\u793a\u4e86\u9ad8\u7ea7\u6a21\u5757 threading<\/code><\/a> \u5982\u4f55\u5b9e\u73b0\u4e3b\u7a0b\u5e8f\u6267\u884c\u7684\u540c\u65f6\u5728\u540e\u53f0\u6267\u884c\u53e6\u4e00\u4e2a\u76f8\u5e94\u7684\u7a0b \u5e8f:import<\/strong>threading<\/strong>, zipfile<\/strong>class<\/strong>AsyncZip<\/strong>(threading.Thread): def<\/strong> __init__(self, infile, outfile): threading.Thread.__init__(self) self.infile = infile self.outfile = outfile def<\/strong> run(self): f = zipfile.ZipFile(self.outfile, ‘w’, zipfile.ZIP_DEFLATED) f.write(self.infile) f.close() print(‘Finished background zip of:’, self.infile) background = AsyncZip(‘mydata.txt’, ‘myarchive.zip’) background.start() print(‘The main program continues to run in foreground.’) background.join() # \u7b49\u5f85\u540e\u53f0\u4efb\u52a1\u7ed3\u675f<\/em> print(‘Main program waited until background was done.’)<\/p>\n\n\n\n

    \u591a\u7ebf\u5c42\u5e94\u7528\u7a0b\u5e8f\u7684\u6700\u5927\u6311\u6218\u5c31\u662f\u534f\u8c03\u884c\u7ebf\u7a0b\u4e4b\u95f4\u6570\u636e\u6216\u8005\u5176\u5b83\u8d44\u6e90\u7684\u5171\u4eab. \u4e3a\u6b64, \u7ebf\u7a0b\u6a21\u5757\u63d0\u4f9b\u4e86\u8bb8\u591a\u540c\u6b65 \u539f\u59cb\u51fd\u6570, \u5305\u62ec\u9501\u5b9a\u3001\u6761\u4ef6\u53d8\u91cf\u548c\u4fe1\u53f7.<\/p>\n\n\n\n

    \u867d\u7136\u6709\u8fd9\u4e9b\u5f3a\u5927\u7684\u5de5\u5177, \u4f46\u8bbe\u8ba1\u4e0a\u7684\u4e00\u4e2a\u5c0f\u9519\u8bef\u4ecd\u7136\u53ef\u4ee5\u5bfc\u81f3\u96be\u4ee5\u6062\u590d\u7684\u95ee\u9898. \u56e0\u6b64, \u5bf9\u4e8e\u534f\u8c03\u5404\u7ebf\u7a0b\u6211\u4eec \u66f4\u503e\u5411\u4e8e\u628a\u7684\u6709\u7684\u8bbf\u95ee\u96c6\u4e2d\u5728\u4e00\u4e2a\u5355\u72ec\u7684\u7ebf\u7a0b\u4e0a, \u8fd9\u4e2a\u7ebf\u7a0b\u4f7f\u7528 queue<\/code><\/a> \u6a21\u5757\u628a\u5176\u5b83\u7ebf\u7a0b\u7684\u8bf7\u6c42\u5168 \u90e8\u96c6\u4e2d\u8d77\u6765. \u5e94\u7528\u7a0b\u5e8f\u4f7f\u7528 Queue<\/code> \u7684\u5bf9\u8c61\u6765\u8fdb\u884c\u8de8\u7ebf\u7a0b\u7684\u4ea4\u6d41\u548c\u534f\u8c03\u53ef\u4ee5\u4f7f\u5f97\u8bbe\u8ba1\u53d8\u5f97\u66f4\u7b80\u5355, \u800c\u4e14\u66f4\u6613\u9605\u8bfb, \u66f4\u53ef\u9760.<\/p>\n\n\n\n

    11.5. \u65e5\u5fd7<\/a><\/h2>\n\n\n\n

    logging<\/code><\/a> \u6a21\u5757\u63d0\u4f9b\u4e00\u6574\u5957\u5bcc\u6709\u7279\u8272\u4e14\u7075\u6d3b\u7684\u65e5\u5fd7\u7cfb\u7edf. \u7528\u6700\u7b80\u5355\u7684\u65b9\u5f0f\u8bf4, \u5c31\u662f\u628a\u65e5\u5fd7\u6d88\u606f\u4f20\u9001 \u7ed9\u4e00\u4e2a\u6587\u4ef6\u6216\u8005 “<\/a>sys.stderr`:import<\/strong>logging<\/strong> logging.debug(‘Debugging information’) logging.info(‘Informational message’) logging.warning(‘Warning:config file %s<\/em> not found’, ‘server.conf’) logging.error(‘Error occurred’) logging.critical(‘Critical error — shutting down’)<\/p>\n\n\n\n

    \u4e0a\u8ff0\u4f1a\u4ea7\u751f\u4ee5\u4e0b\u7684\u8f93\u51fa:WARNING:root:Warning:config file server.conf not<\/strong> found ERROR:root:Error occurred CRITICAL:root:Critical error — shutting down<\/p>\n\n\n\n

    \u9ed8\u8ba4\u7684\u60c5\u51b5\u4e0b, \u4fe1\u606f\u548c\u8c03\u8bd5\u6d88\u606f\u4f1a\u88ab\u6355\u6349, \u5e76\u53d1\u9001\u7ed9\u6807\u51c6\u9519\u8bef\u6d41. \u5176\u5b83\u7684\u4e00\u4e9b\u8f93\u51fa\u9009\u9879\u5305\u62ec\u7ecf\u7531\u90ae\u4ef6\u3001\u6570\u636e\u62a5 \u5957\u63a5\u5b57\u6216\u8005\u53d1\u9001\u7ed9\u4e00\u4e2aHTTP\u670d\u52a1\u5668\u7684\u8def\u7531\u6d88\u606f. \u65b0\u7684\u5730\u6ee4\u5668\u53ef\u4ee5\u9009\u62e9\u4e0d\u540c\u7684\u57fa\u4e8e\u6d88\u606f\u4f18\u5148\u7ea7\u7684\u7684\u8def\u7531, \u800c\u6d88\u606f \u7684\u4f18\u5148\u7ea7\u6709: DEBUG<\/code>, INFO<\/code>, WARING<\/code>, ERROR<\/code>, \u548c CRITICAL<\/code>.<\/p>\n\n\n\n

    \u65e5\u5fd7\u7cfb\u7edf\u53ef\u4ee5\u88abPython\u8bed\u8a00\u914d\u7f6e, \u6216\u8005\u88ab\u4e00\u4e2a\u7528\u6237\u7684\u53ef\u7f16\u8f91\u7684\u914d\u7f6e\u6587\u4ef6\u52a0\u8f7d, \u4ee5\u6b64\u53bb\u81ea\u5b9a\u4e49\u65e5\u5fd7\u800c\u4e0d\u7528\u53bb\u4fee\u7a0b\u5e8f\u672c\u8eab.<\/p>\n\n\n\n

    11.6. \u5f31\u5f15\u7528<\/a><\/h2>\n\n\n\n

    Python\u8bed\u8a00\u81ea\u52a8\u7ba1\u7406\u5185\u5b58\uff08\u5927\u591a\u6570\u5bf9\u8c61\u90fd\u6709\u4e00\u4e2a\u5bf9\u5b83\u7684\u5f15\u7528\u800c garbage collection<\/a> \u5bf9\u5b83\u4eec\u8fdb \u884c\u56de\u6536\uff09. \u5f53\u6700\u540e\u4e00\u4e2a\u5f15\u7528\u7ed3\u675f\u4e4b\u540e\u5185\u5b58\u5373\u523b\u88ab\u56de\u6536.<\/p>\n\n\n\n

    \u8fd9\u79cd\u673a\u5236\u5bf9\u5927\u591a\u6570\u5e94\u7528\u7a0b\u5e8f\u6765\u8bf4\u90fd\u662f\u6709\u6548\u7684, \u4f46\u4e5f\u6709\u5076\u7136\u60c5\u51b5, \u53ea\u6709\u5f53\u5b83\u4eec\u88ab\u5176\u5b83\u4e1c\u897f\u5f15\u7528\u7684\u65f6\u5019\u624d\u9700\u8981\u53bb \u8ddf\u8e2a\u5bf9\u8c61. \u4e0d\u5e78\u7684\u662f, \u4ec5\u4ec5\u662f\u8ddf\u8e2a\u5b83\u4eec\u4e5f\u9700\u8981\u521b\u5efa\u4e00\u4e2a\u5f15\u7528. weakref<\/code><\/a> \u6a21\u5757\u63d0\u4f9b\u4e00\u4e9b\u5de5\u5177\u53ef\u4ee5 \u8fbe\u5230\u540c\u6837\u7684\u6548\u679c\u800c\u4e0d\u7528\u53bb\u521b\u5efa\u4e00\u4e2a\u5f15\u7528. \u5f53\u4e0d\u518d\u9700\u8981\u8fd9\u4e2a\u5bf9\u8c61\u7684\u65f6\u5019, \u5b83\u4f1a\u81ea\u52a8\u5730\u4ece\u4e00\u4e2aweakref\u8868\u4e2d\u79fb\u9664 \u7136\u540e\u9275\u53d1\u5bf9weadref\u5bf9\u8c61\u7684\u56de\u8c03. \u901a\u5e38\u5e94\u7528\u7a0b\u5e8f\u90fd\u4f1a\u5bf9\u90a3\u4e9b\u521b\u5efa\u65f6\u82b1\u8d39\u8f83\u591a\u65f6\u95f4\u7684\u5bf9\u8c61\u63d0\u4f9b\u4e00\u4e2a\u7f13\u5b58:>>> <\/strong>import<\/strong>weakref<\/strong>, gc<\/strong>>>> <\/strong>class<\/strong>A<\/strong>: … <\/strong>def<\/strong> __init__(self, value): …<\/strong> self.value = value … <\/strong>def<\/strong> __repr__(self): … <\/strong>return<\/strong> str(self.value) …<\/strong>>>> <\/strong>a = A(10) # \u521b\u5efa\u4e00\u4e2a\u5f15\u7528<\/em>>>> <\/strong>d = weakref.WeakValueDictionary() >>> <\/strong>d[‘primary’] = a # \u6ca1\u6709\u521b\u5efa\u4e00\u4e2a\u5f15\u7528<\/em>>>> <\/strong>d[‘primary’] # \u5982\u679c\u5b58\u5728\u7684\u8bdd\u83b7\u53d6\u8fd9\u4e2a\u5bf9\u65ec<\/em> 10 >>> <\/strong>del<\/strong> a # \u79fb\u9664\u8fd9\u4e2a\u5f15\u548c<\/em>>>> <\/strong>gc.collect() # \u76f4\u63a5\u8c03\u7528\u56de\u6536\u673a\u5236<\/em> 0 >>> <\/strong>d[‘primary’] # \u8c03\u7528\u7684\u5165\u53e3\u5df2\u7ecf\u81ea\u52a8\u88ab\u79fb\u9664\u4e86<\/em> Traceback (most recent call last): File “<stdin>”, line 1, in <module> d[‘primary’] # \u8c03\u7528\u7684\u5165\u53e3\u5df2\u7ecf\u81ea\u52a8\u88ab\u79fb\u9664\u4e86<\/em> File “C:\/python31\/lib\/weakref.py”, line 46, in __getitem__ o = self.data[key]() KeyError: ‘primary’<\/p>\n\n\n\n

    11.7. \u5904\u7406\u5217\u8868\u7684\u5de5\u5177<\/a><\/h2>\n\n\n\n

    \u8bb8\u591a\u6570\u636e\u7684\u7ed3\u6784\u90fd\u9700\u8981\u7528\u5230\u5185\u7f6e\u7684\u5217\u8868\u7c7b\u578b. \u4f46\u6709\u65f6\u5019\u9700\u8981\u5728\u53ef\u9009\u62e9\u5730\u4e0d\u540c\u5448\u73b0\u65b9\u5f0f\u4e2d\u8fdb\u884c\u6743\u8861.<\/p>\n\n\n\n

    array<\/code><\/a> \u6a21\u5757\u63d0\u4f9b\u4e86\u4e00\u4e2a array()<\/code><\/a> \u5bf9\u8c61, \u8fd9\u4e2a\u5bf9\u8c61\u50cf\u4e00\u4e2a\u5217\u8868\u4e00\u6837\u5b58\u50a8\u540c\u4e00\u7c7b\u578b\u7684\u6570\u636e, \u800c\u4e14\u66f4\u7b80\u6d01. \u4e0b\u9762\u8fd9\u4e2a\u4f8b\u5b50\u6f14\u793a\u4e86\u5c06\u4e00\u7ec4\u6570\u5b57\u4ee5\u4e24\u4e2a\u5b57\u8282\u7684\u65e0\u7b26\u53f7\u6574\u6570\uff08\u7c7b\u578b\u7801 H<\/code>) \u5f62\u5f0f\u5b58\u50a8\u4e3a\u4e00\u4e2a\u6570\u7ec4 \u800c\u4e0d\u662f\u901a\u5e38\u7684Python\u7684list\u5bf9\u8c61\u768416\u5b57\u8282\u7684\u5f62\u5f0f:>>> <\/strong>from<\/strong>array<\/strong>import<\/strong> array >>> <\/strong>a = array(‘H’, [4000, 10, 700, 22222]) >>> <\/strong>sum(a) 26932 >>> <\/strong>a[1:3] array(‘H’, [10, 700])<\/p>\n\n\n\n

    cllections<\/code> \u6a21\u5757\u63d0\u4f9b\u4e86\u4e00\u4e2a deque()<\/code> \u5bf9\u8c61, \u5b83\u53ef\u4ee5\u50cf\u4e00\u4e2a\u5217\u8868\u4e00\u6837\u5728\u5de6\u8fb9\u8fdb\u884c \u5feb\u901f\u7684apend\u548cpop\u64cd\u4f5c, \u4f46\u5728\u5185\u90e8\u67e5\u5bfb\u65f6\u76f8\u5bf9\u8f83\u6162. \u8fd9\u4e9b\u5bf9\u8c61\u53ef\u4ee5\u65b9\u4fbf\u5730\u6210\u4e3a\u4e00\u4e2a\u961f\u5217\u548c\u5730\u884c\u5e7f\u5ea6\u4f18\u5148\u6811 \u641c\u7d22:>>> <\/strong>from<\/strong>collections<\/strong>import<\/strong> deque >>> <\/strong>d = deque([“task1”, “task2”, “task3”]) >>> <\/strong>d.append(“task4”) >>> <\/strong>print(“Handling”, d.popleft()) Handling task1 unsearched = deque([starting_node]) def breadth_first_search(unsearched): node = unsearched.popleft() for m in gen_moves(node): if is_goal(m): return m unsearched.append(m)<\/p>\n\n\n\n

    \u6b64\u5916, \u6807\u51c6\u5e93\u91cc\u4e5f\u63d0\u4f9b\u4e86\u4e00\u4e9b\u5176\u5b83\u7684\u5de5\u5177, \u5982 bisect<\/code><\/a> \u6a21\u5757, \u5b83\u6709\u4e00\u4e9b\u5bf9\u5217\u8868\u8fdb\u884c\u6392\u5e8f\u7684\u51fd\u6570:>>> <\/strong>import<\/strong>bisect<\/strong>>>> <\/strong>scores = [(100, ‘perl’), (200, ‘tcl’), (400, ‘lua’), (500, ‘python’)] >>> <\/strong>bisect.insort(scores, (300, ‘ruby’)) >>> <\/strong>scores [(100, ‘perl’), (200, ‘tcl’), (300, ‘ruby’), (400, ‘lua’), (500, ‘python’)]<\/p>\n\n\n\n

    heapq<\/code><\/a> \u6a21\u5757\u63d0\u4f9b\u4e86\u4e00\u4e9b\u51fd\u6570\u901a\u8fc7\u5e38\u89c4\u5217\u8868\u53bb\u5b9e\u73b0\u5806. \u6700\u4f4e\u5c42\u7684\u5165\u53e3\u901a\u5e38\u90fd\u5728\u96f6\u5904. \u8fd9\u5bf9\u4e8e\u91cd\u590d\u8bbf \u95ee\u4e00\u4e9b\u5f88\u5c0f\u7684\u5143\u7d20\u4f46\u53c8\u4e0d\u60f3\u5bf9\u6574\u4e2a\u5217\u8868\u8fdb\u884c\u6392\u5e8f\u7684\u5e94\u7528\u7a0b\u5e8f\u6765\u8bf4\u5341\u5206\u6709\u6548:>>> <\/strong>from<\/strong>heapq<\/strong>import<\/strong> heapify, heappop, heappush >>> <\/strong>data = [1, 3, 5, 7, 9, 2, 4, 6, 8, 0] >>> <\/strong>heapify(data) # \u5c06\u5217\u8868\u91cd\u65b0\u6574\u7406\u6210\u5806<\/em>>>> <\/strong>heappush(data, -5) # \u589e\u52a0\u4e00\u4e2a\u65b0\u5165\u53e3<\/em>>>> <\/strong>[heappop(data) for<\/strong> i in<\/strong> range(3)] # \u53d6\u51fa\u8fd9\u4e09\u4e2a\u6700\u5c0f\u7684\u5165\u53e3<\/em> [-5, 0, 1]<\/p>\n\n\n\n

    11.8. \u5341\u8fdb\u5236\u6d6e\u70b9\u6570\u7684\u8fd0\u7b97<\/a><\/h2>\n\n\n\n

    decimal<\/code><\/a> \u6a21\u5757\u63d0\u4f9b\u4e86\u4e00\u4e2a Decimal<\/code> \u9488\u5bf9\u5341\u8fdb\u5236\u6d6e\u70b9\u5c0f\u6570\u8fd0\u7b97\u7684\u6570\u636e\u7c7b\u578b. \u4e0e\u5185 \u7f6e\u7684\u6570\u636e\u7c7b\u578b float<\/code><\/a> \uff08\u9488\u5bf9\u4e8c\u8fdb\u5236\u6d6e\u70b9\u5c0f\u6570\uff09 \u76f8\u6bd4\u800c\u8a00, \u5b83\u5bf9\u4ee5\u4e0b\u51e0\u79cd\u60c5\u51b5\u66f4\u4e3a\u6709\u6548<\/p>\n\n\n\n