{"id":7001,"date":"2020-10-05T12:41:07","date_gmt":"2020-10-05T04:41:07","guid":{"rendered":"https:\/\/egonlin.com\/?p=7001"},"modified":"2022-06-05T12:56:44","modified_gmt":"2022-06-05T04:56:44","slug":"python-3-9%e6%96%b0%e7%89%b9%e6%80%a7","status":"publish","type":"post","link":"https:\/\/egonlin.com\/?p=7001","title":{"rendered":"Python 3.9\u65b0\u7279\u6027"},"content":{"rendered":"

Python 3.9\u65b0\u7279\u6027\u6982\u8ff0<\/h1>\n

\"\"<\/div>
\nPython 3.9 \u5df2\u4e8e 2020\u5e7410 \u6708 5 \u65e5\u53d1\u5e03\uff0c\u65b0\u7248\u672c\u7684\u7279\u6027\uff0c\u4f60 get \u5230\u4e86\u5417\uff1f\u5bf9\u4e8e Python \u7a0b\u5e8f\u5458\u6765\u8bf4\uff0c\u8fd9\u53c8\u662f\u4e00\u4e2a\u4ee4\u4eba\u5174\u594b\u7684\u65f6\u523b\u3002
\n
\"file\"<\/div>
\n\u76f8\u6bd4\u4e8e\u4e4b\u524d\u7684\u7248\u672c\uff0cPython 3.9 \u6709\u54ea\u4e9b\u503c\u5f97\u8ba8\u8bba\u7684\u529f\u80fd\u5462\uff1f
\n
\"\"<\/div>
\n\u7b80\u800c\u8a00\u4e4b\uff0c\u4ece\u5b57\u5178\u66f4\u65b0 \/ \u5408\u5e76\u5230\u6dfb\u52a0\u65b0\u7684\u5b57\u7b26\u4e32\u65b9\u6cd5\uff0c\u518d\u5230 zoneinfo \u5e93\u7684\u5f15\u5165\uff0cPython 3.9 \u6dfb\u52a0\u4e86\u8bb8\u591a\u65b0\u7279\u6027\u3002\u6b64\u5916\uff0c\u8be5\u7248\u672c\u8fd8\u5f15\u5165\u4e86\u4e00\u79cd\u7a33\u5b9a\u3001\u9ad8\u6027\u80fd\u7684\u65b0\u578b\u89e3\u6790\u5668\u3002<\/p>\n

\u6807\u51c6\u5e93\u66f4\u65b0\u4e86\u8bb8\u591a\u65b0\u7279\u6027\uff0c\u5e76\u6dfb\u52a0\u4e86\u65b0\u6a21\u5757 zoneinfo \u548c graphlib\u3002\u6b64\u5916\u8be5\u7248\u672c\u4e5f\u5bf9\u8bb8\u591a\u6a21\u5757\u8fdb\u884c\u4e86\u6539\u8fdb\uff0c\u5982 ast\u3001asyncio\u3001concurrent.futures\u3001multiprocessing\u3001xml \u7b49\u3002<\/p>\n

\u73b0\u5728\u8ba9\u6211\u4eec\u4e00\u8d77\u63a2\u7d22 Python 3.9 \u7684\u65b0\u7279\u6027\u3002
\nPython 3.9\uff1a10 \u4e2a\u6709\u8da3\u7684\u65b0\u7279\u6027<\/p>\n

1. \u5b57\u5178\u66f4\u65b0\u548c\u5408\u5e76<\/h4>\n

\u5b57\u5178\u6dfb\u52a0\u4e24\u4e2a\u65b0\u7684\u8fd0\u7b97\u7b26\uff1a<\/p>\n

\u5b57\u5178\u5408\u5e76\uff1a|<\/p>\n

\u5b57\u5178\u66f4\u65b0\uff1a|=<\/p>\n

2. \u57fa\u4e8e PEG \u7684\u9ad8\u6027\u80fd\u89e3\u6790\u5668<\/h4>\n

Python 3.9 \u63d0\u51fa\u7528\u9ad8\u6027\u80fd\u548c\u7a33\u5b9a\u7684\u57fa\u4e8e PEG \u7684\u89e3\u6790\u5668\u53d6\u4ee3\u5f53\u524d\u57fa\u4e8e LL(1) \u7684 Python \u89e3\u6790\u5668\u3002<\/p>\n

\u5f53\u524d\u7684 CPython \u89e3\u6790\u5668\u57fa\u4e8e LL(1)\uff0cLL(1) \u89e3\u6790\u5668\u662f\u4e00\u4e2a\u81ea\u9876\u5411\u4e0b\u7684\u89e3\u6790\u5668\uff0c\u5b83\u4ece\u5de6\u5230\u53f3\u89e3\u6790\u8f93\u5165\u3002<\/p>\n

Python 3.9 \u63d0\u8bae\u5c06 LL(1) \u66ff\u6362\u4e3a\u65b0\u7684\u57fa\u4e8e PEG \u7684\u89e3\u6790\u5668\uff0c\u8fd9\u610f\u5473\u7740\u5b83\u5c06\u89e3\u9664\u5f53\u524d LL(1) \u8bed\u6cd5\u5bf9 Python \u7684\u9650\u5236\u3002\u6b64\u5916\uff0c\u5f53\u524d\u7684\u89e3\u6790\u5668\u4fee\u8865\u4e86\u8bb8\u591a\u5c06\u8981\u5220\u9664\u7684 hack\u3002\u56e0\u6b64\uff0c\u4ece\u957f\u8fdc\u6765\u770b\uff0c\u8fd9\u4f1a\u964d\u4f4e\u7ef4\u62a4\u6210\u672c\u3002<\/p>\n

3. \u65b0\u578b\u5b57\u7b26\u4e32\u51fd\u6570\uff1a\u5220\u9664\u524d\u7f00\u548c\u540e\u7f00<\/h4>\n

Python 3.9 \u5c06\u4e24\u4e2a\u65b0\u51fd\u6570\u6dfb\u52a0\u5230 str \u5bf9\u8c61\uff1a<\/p>\n

\u7b2c\u4e00\u4e2a\u51fd\u6570\u7528\u4e8e\u5220\u9664\u524d\u7f00\uff1astr.removeprefix(prefix)<\/p>\n

\u7b2c\u4e8c\u4e2a\u51fd\u6570\u7528\u4e8e\u5220\u9664\u540e\u7f00\uff1astr.removesuffix(suffix)<\/p>\n

4. \u5bf9\u5185\u7f6e\u6cdb\u578b\u7c7b\u578b\u63d0\u4f9b\u7c7b\u578b\u63d0\u793a<\/h4>\n

Python 3.9 \u901a\u8fc7\u5220\u9664\u5e76\u884c\u7c7b\u578b\u5c42\u6b21\u7ed3\u6784\uff0c\u4f7f\u6ce8\u91ca\u7a0b\u5e8f\u53d8\u5f97\u66f4\u52a0\u7b80\u5355\u3002Python 3.9 \u652f\u6301 typing \u6a21\u5757\u6240\u6709\u6807\u51c6\u96c6\u5408\u4e2d\u7684\u6cdb\u578b\u8bed\u6cd5\u3002<\/p>\n

\u6211\u4eec\u53ef\u4ee5\u5c06 list \u6216 dict \u76f4\u63a5\u4f5c\u4e3a\u5217\u8868\u548c\u5b57\u5178\u7684\u7c7b\u578b\u6ce8\u91ca\uff0c\u800c\u4e0d\u5fc5\u4f9d\u8d56 typing.List \u6216\u8005 typing.Dict\u3002\u56e0\u6b64\uff0c\u4ee3\u7801\u73b0\u5728\u770b\u8d77\u6765\u66f4\u52a0\u7b80\u6d01\uff0c\u800c\u4e14\u66f4\u5bb9\u6613\u7406\u89e3\u548c\u89e3\u91ca\u3002<\/p>\n

5. DateTime \u652f\u6301 IANA \u65f6\u533a<\/h4>\n

zoneinfo \u6a21\u5757\u88ab\u521b\u5efa\u51fa\u6765\u652f\u6301 IANA \u65f6\u533a\u6570\u636e\u5e93\u3002\u5bf9 IANA \u65f6\u533a\u6570\u636e\u5e93\u7684\u652f\u6301\u5df2\u7ecf\u6dfb\u52a0\u5230\u6807\u51c6\u5e93\u4e2d\u3002<\/p>\n

IANA \u65f6\u533a\u901a\u5e38\u79f0\u4e3a tz \u6216 zone info\u3002\u5b58\u5728\u8bb8\u591a\u5177\u5907\u4e0d\u540c\u641c\u7d22\u8def\u5f84\u7684 IANA \u65f6\u533a\uff0c\u7528\u4e8e\u4e3a date-time \u5bf9\u8c61\u6307\u5b9a IANA \u65f6\u533a\u3002\u4f8b\u5982\uff0c\u6211\u4eec\u53ef\u4ee5\u5c06\u5bf9 datetime \u5bf9\u8c61\u8bbe\u7f6e\u641c\u7d22\u8def\u5f84\u300cContinent\/City\u300d\u6765\u8bbe\u7f6e tzinfo\u3002<\/p>\n

\u5982\u679c\u4f20\u5165\u4e00\u4e2a\u65e0\u6548\u7684\u5bc6\u94a5\uff0c\u5219\u4f1a\u5f15\u53d1 zoneinfo.ZoneInfoNotFoundError \u5f02\u5e38\u3002<\/p>\n

6. concurrent.futures \u4f18\u5316<\/h4>\n

concurrent.futures.Executor.shutdown() \u4e2d\u6dfb\u52a0\u4e86\u4e00\u4e2a\u65b0\u53c2\u6570 cancel_futures\u3002\u6b64\u53c2\u6570\u53ef\u4ee5\u53d6\u6d88\u5c1a\u672a\u6267\u884c\u7684\u5e76\u53d1\u4efb\u52a1\u3002\u5728 Python 3.9 \u4e4b\u524d\u4e3b\u8fdb\u7a0b\u53ea\u6709\u5728\u6240\u6709\u5e76\u53d1\u4efb\u52a1\u5b8c\u6210\u540e\u624d\u80fd\u5173\u95ed executor \u5bf9\u8c61\u3002<\/p>\n

\u65b0\u53c2\u6570 cancel_futures \u5df2\u88ab\u6dfb\u52a0\u5230 ThreadPoolExecutor \u4ee5\u53ca ProcessPoolExecutor\u3002\u5b83\u7684\u5de5\u4f5c\u65b9\u5f0f\u662f\uff1a\u5f53\u53c2\u6570\u7684\u503c\u4e3a True \u65f6\uff0c\u5728\u8c03\u7528 shutdown() \u51fd\u6570\u65f6\u53d6\u6d88\u6240\u6709\u5f85\u5904\u7406\u7684\u4efb\u52a1\u3002<\/p>\n

7. \u5f02\u6b65\u7f16\u7a0b\u548c\u591a\u8fdb\u7a0b\u4f18\u5316<\/h4>\n

Python 3.9 \u5bf9\u5f02\u6b65\u7f16\u7a0b\uff08asyncio\uff09\u548c\u591a\u8fdb\u7a0b\u5e93\u8fdb\u884c\u4e86\u4f18\u5316\u3002<\/p>\n

    \n
  1. \u65b0\u589e\u4e86 coroutines\u3001shutdown_default_executor() \u548c asyncio.to_thread() \u3002shutdown_default_executor \u8d1f\u8d23\u5173\u95ed\u9ed8\u8ba4 executor\uff0casyncio.to_thread() \u4e3b\u8981\u7528\u4e8e\u5728\u4e00\u6761\u5355\u72ec\u7684\u7ebf\u7a0b\u4e2d\u8fd0\u884c IO \u5bc6\u96c6\u578b\u51fd\u6570\uff0c\u4ee5\u907f\u514d\u4e8b\u4ef6\u5faa\u73af\u3002<\/li>\n<\/ol>\n

    \u5173\u4e8e\u591a\u8fdb\u7a0b\u5e93\u7684\u6539\u8fdb\uff0cPython 3.9 \u5411 multiprocessing.SimpleQueue \u7c7b\u6dfb\u52a0\u4e86\u65b0\u65b9\u6cd5 close()\u3002<\/p>\n

    \u6b64\u65b9\u6cd5\u53ef\u4ee5\u663e\u5f0f\u5730\u5173\u95ed\u961f\u5217\u3002\u8fd9\u5c06\u786e\u4fdd\u961f\u5217\u5173\u95ed\u5e76\u4e14\u505c\u7559\u65f6\u95f4\u4e0d\u4f1a\u6bd4\u9884\u671f\u957f\u3002\u503c\u5f97\u6ce8\u610f\u7684\u662f\uff0c\u4e00\u65e6\u5173\u95ed\u961f\u5217\uff0c\u5c31\u4e0d\u80fd\u8c03\u7528 get()\u3001put() \u548c empty() \u65b9\u6cd5\u3002<\/p>\n

    8. \u7edf\u4e00\u7684\u8f6f\u4ef6\u5305\u5bfc\u5165\u9519\u8bef<\/h4>\n

    Python3.9 \u4e4b\u524d\u7684\u7248\u672c\u5728\u5bfc\u5165 Python \u5e93\u65f6\u5b58\u5728\u7684\u4e3b\u8981\u95ee\u9898\u662f\uff1a\u5f53\u76f8\u5bf9\u5bfc\u5165\u8d85\u51fa\u5176\u9876\u7ea7\u5305\u65f6\uff0cPython \u4e2d\u7684\u5bfc\u5165\u884c\u4e3a\u4e0d\u4e00\u81f4\u3002<\/p>\n

    builtins.import<\/strong>() \u5f15\u53d1 ValueError\uff0c\u800c importlib.import<\/strong>() \u5f15\u53d1 ImportError\u3002Python3.9 \u7248\u672c\u8fdb\u884c\u4e86\u4fee\u590d\uff0c\u5b83\u5c06\u7edf\u4e00\u5f15\u53d1 ImportError\u3002<\/p>\n

    9. \u751f\u6210\u968f\u673a\u5b57\u8282<\/h4>\n

    Python 3.9 \u7248\u672c\u4e2d\u6dfb\u52a0\u4e86\u65b0\u7684\u51fd\u6570 random.Random.randbytes()\u3002\u8be5\u51fd\u6570\u53ef\u7528\u4e8e\u751f\u6210\u968f\u673a\u5b57\u8282\u3002<\/p>\n

    Python \u652f\u6301\u751f\u6210\u968f\u673a\u6570\uff0c\u4f46\u5982\u679c\u9700\u8981\u751f\u6210\u968f\u673a\u5b57\u8282\u5462\uff1f\u5728 Python3.9 \u7248\u672c\u4e4b\u524d\uff0c\u5f00\u53d1\u4eba\u5458\u5fc5\u987b\u60f3\u65b9\u8bbe\u6cd5\u751f\u6210\u968f\u673a\u5b57\u8282\u3002\u5c3d\u7ba1\u4ed6\u4eec\u53ef\u4ee5\u4f7f\u7528 os.getrandom()\u3001os.urandom() \u6216\u8005 secrets.token_bytes() \u6765\u751f\u6210\u968f\u673a\u5b57\u8282\uff0c\u4f46\u8fd9\u4e9b\u65b9\u6cd5\u65e0\u6cd5\u751f\u6210\u4f2a\u968f\u673a\u6a21\u5f0f\u3002<\/p>\n

    \u4e3a\u4e86\u786e\u4fdd\u968f\u673a\u6570\u7684\u4ea7\u751f\u7b26\u5408\u9884\u671f\u884c\u4e3a\uff0c\u5e76\u4e14\u8fc7\u7a0b\u53ef\u590d\u73b0\uff0c\u5f00\u53d1\u4eba\u5458\u901a\u5e38\u5c06\u79cd\u5b50\uff08seed\uff09\u4e0e random.Random \u6a21\u5757\u4e00\u8d77\u4f7f\u7528\u3002\u56e0\u6b64\uff0cPython 3.9 \u6dfb\u52a0\u4e86 random.Random.randbytes() \u65b9\u6cd5\uff0c\u4ee5\u53ef\u63a7\u7684\u65b9\u5f0f\u751f\u6210\u968f\u673a\u5b57\u8282\u3002<\/p>\n

    10. \u4fee\u590d\u5b57\u7b26\u4e32\u66ff\u6362\u51fd\u6570<\/h4>\n

    \u5728 Python 3.9 \u7248\u672c\u4e4b\u524d\uff0c\u5bf9\u4e8e\u6240\u6709\u975e\u96f6\u7684 n\uff0c"".replace("",s,n) \u8fd4\u56de\u7a7a\u5b57\u7b26\u4e32\u800c\u4e0d\u662f s\u3002\u8fd9\u4e2a\u9519\u8bef\u4f7f\u7528\u6237\u56f0\u60d1\uff0c\u5e76\u5bfc\u81f4\u5e94\u7528\u7a0b\u5e8f\u7684\u4e0d\u4e00\u81f4\u884c\u4e3a\u3002<\/p>\n

    Python 3.9 \u4fee\u590d\u4e86\u8be5\u95ee\u9898\uff0c\u4e0d\u7ba1 n \u662f\u5426\u4e3a 0\uff0c\u5176\u7ed3\u679c\u90fd\u4e0e "".replace("", s) \u4e00\u81f4\u3002<\/p>\n

    \u5982\u679c\u5927\u5bb6\u60f3\u6df1\u5165\u4e86\u89e3\u66f4\u591a\u7ec6\u8282\uff0c\u8bf7\u67e5\u9605\u5b98\u65b9\u6587\u6863\uff1ahttps:\/\/docs.python.org\/zh-cn\/3.9\/whatsnew\/3.9.html<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

    Python 3.9\u65b0\u7279\u6027\u6982\u8ff0 Python 3.9 \u5df2\u4e8e 2020\u5e7410 \u6708 5 \u65e5\u53d1\u5e03\uff0c\u65b0\u7248\u672c\u7684\u7279\u6027\uff0c\u4f60 […]<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[410],"tags":[],"_links":{"self":[{"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/posts\/7001"}],"collection":[{"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=7001"}],"version-history":[{"count":0,"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/posts\/7001\/revisions"}],"wp:attachment":[{"href":"https:\/\/egonlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=7001"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=7001"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=7001"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}