{"id":4979,"date":"2021-01-22T16:19:34","date_gmt":"2021-01-22T08:19:34","guid":{"rendered":"https:\/\/damogame.cn\/wordpress\/?p=4979"},"modified":"2021-01-22T16:19:34","modified_gmt":"2021-01-22T08:19:34","slug":"python-async-await%e5%85%a5%e9%97%a8%e6%8c%87%e5%8d%97","status":"publish","type":"post","link":"https:\/\/i007.cc\/wordpress\/archives\/4979","title":{"rendered":"Python Async\/Await\u5165\u95e8\u6307\u5357"},"content":{"rendered":"
\u539f\u6587\u5730\u5740<\/a><\/div>\n
<\/div>\n
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\u672c\u6587\u5c06\u4f1a\u8bb2\u8ff0Python 3.5\u4e4b\u540e\u51fa\u73b0\u7684async\/await\u7684\u4f7f\u7528\u65b9\u6cd5\uff0c\u4ee5\u53ca\u5b83\u4eec\u7684\u4e00\u4e9b\u4f7f\u7528\u76ee\u7684\uff0c\u5982\u679c\u9519\u8bef\uff0c\u6b22\u8fce\u6307\u6b63\u3002<\/p>\n

\u6628\u5929\u770b\u5230David Beazley\u572816\u5e74\u7684\u4e00\u4e2a\u6f14\u8bb2\uff1aFear and Awaiting in Async<\/a>\uff0c\u7ed9\u4e86\u6211\u4e0d\u5c11\u7684\u611f\u609f\u548c\u542f\u53d1\uff0c\u4e8e\u662f\u60f3\u68b3\u7406\u4e0b\u81ea\u5df1\u7684\u601d\u8def\uff0c\u6240\u4ee5\u6709\u4e86\u4ee5\u4e0b\u8fd9\u7bc7\u6587\u7ae0\u3002<\/p>\n

Python\u57283.5\u7248\u672c\u4e2d\u5f15\u5165\u4e86\u5173\u4e8e\u534f\u7a0b\u7684\u8bed\u6cd5\u7cd6async\u548cawait\uff0c\u5173\u4e8e\u534f\u7a0b\u7684\u6982\u5ff5\u53ef\u4ee5\u5148\u770b\u6211\u5728\u4e0a\u4e00\u7bc7\u6587\u7ae0<\/a>\u63d0\u5230\u7684\u5185\u5bb9\u3002<\/p>\n

\u770b\u4e0bPython\u4e2d\u5e38\u89c1\u7684\u51e0\u79cd\u51fd\u6570\u5f62\u5f0f\uff1a<\/p>\n

1. \u666e\u901a\u51fd\u6570<\/p>\n

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def<\/span> function<\/span>():<\/span>\r\n    return<\/span> 1<\/span><\/code><\/pre>\n<\/div>\n
2. \u751f\u6210\u5668\u51fd\u6570<\/p>\n
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def<\/span> generator<\/span>():<\/span>\r\n    yield<\/span> 1<\/span><\/code><\/pre>\n<\/div>\n
\u57283.5\u8fc7\u540e\uff0c\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528async\u4fee\u9970\u5c06\u666e\u901a\u51fd\u6570\u548c\u751f\u6210\u5668\u51fd\u6570\u5305\u88c5\u6210\u5f02\u6b65\u51fd\u6570\u548c\u5f02\u6b65\u751f\u6210\u5668\u3002<\/p>\n
3. \u5f02\u6b65\u51fd\u6570\uff08\u534f\u7a0b\uff09<\/p>\n
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async<\/span> def<\/span> async_function<\/span>():<\/span>\r\n    return<\/span> 1<\/span><\/code><\/pre>\n<\/div>\n
4. \u5f02\u6b65\u751f\u6210\u5668<\/p>\n
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async<\/span> def<\/span> async_generator<\/span>():<\/span>\r\n    yield<\/span> 1<\/span><\/code><\/pre>\n<\/div>\n
\u901a\u8fc7\u7c7b\u578b\u5224\u65ad\u53ef\u4ee5\u9a8c\u8bc1\u51fd\u6570\u7684\u7c7b\u578b<\/p>\n
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import<\/span> types<\/span>\r\nprint<\/span>(<\/span>type<\/span>(<\/span>function<\/span>)<\/span> is<\/span> types<\/span>.<\/span>FunctionType<\/span>)<\/span>\r\nprint<\/span>(<\/span>type<\/span>(<\/span>generator<\/span>())<\/span> is<\/span> types<\/span>.<\/span>GeneratorType<\/span>)<\/span>\r\nprint<\/span>(<\/span>type<\/span>(<\/span>async_function<\/span>())<\/span> is<\/span> types<\/span>.<\/span>CoroutineType<\/span>)<\/span>\r\nprint<\/span>(<\/span>type<\/span>(<\/span>async_generator<\/span>())<\/span> is<\/span> types<\/span>.<\/span>AsyncGeneratorType<\/span>)<\/span><\/code><\/pre>\n<\/div>\n
\u76f4\u63a5\u8c03\u7528\u5f02\u6b65\u51fd\u6570\u4e0d\u4f1a\u8fd4\u56de\u7ed3\u679c\uff0c\u800c\u662f\u8fd4\u56de\u4e00\u4e2acoroutine\u5bf9\u8c61\uff1a<\/p>\n
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print<\/span>(<\/span>async_function<\/span>())<\/span>\r\n# <coroutine object async_function at 0x102ff67d8><\/span><\/code><\/pre>\n<\/div>\n
\u534f\u7a0b\u9700\u8981\u901a\u8fc7\u5176\u4ed6\u65b9\u5f0f\u6765\u9a71\u52a8\uff0c\u56e0\u6b64\u53ef\u4ee5\u4f7f\u7528\u8fd9\u4e2a\u534f\u7a0b\u5bf9\u8c61\u7684send\u65b9\u6cd5\u7ed9\u534f\u7a0b\u53d1\u9001\u4e00\u4e2a\u503c\uff1a<\/p>\n
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print<\/span>(<\/span>async_function<\/span>()<\/span>.<\/span>send<\/span>(<\/span>None<\/span>))<\/span><\/code><\/pre>\n<\/div>\n
\u4e0d\u5e78\u7684\u662f\uff0c\u5982\u679c\u901a\u8fc7\u4e0a\u9762\u7684\u8c03\u7528\u4f1a\u629b\u51fa\u4e00\u4e2a\u5f02\u5e38\uff1a<\/p>\n
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StopIteration<\/span>:<\/span> 1<\/span><\/code><\/pre>\n<\/div>\n
\u56e0\u4e3a\u751f\u6210\u5668\/\u534f\u7a0b\u5728\u6b63\u5e38\u8fd4\u56de\u9000\u51fa\u65f6\u4f1a\u629b\u51fa\u4e00\u4e2aStopIteration\u5f02\u5e38\uff0c\u800c\u539f\u6765\u7684\u8fd4\u56de\u503c\u4f1a\u5b58\u653e\u5728StopIteration\u5bf9\u8c61\u7684value\u5c5e\u6027\u4e2d\uff0c\u901a\u8fc7\u4ee5\u4e0b\u6355\u83b7\u53ef\u4ee5\u83b7\u53d6\u534f\u7a0b\u771f\u6b63\u7684\u8fd4\u56de\u503c\uff1a<\/p>\n
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try<\/span>:<\/span>\r\n    async_function<\/span>()<\/span>.<\/span>send<\/span>(<\/span>None<\/span>)<\/span>\r\nexcept<\/span> StopIteration<\/span> as<\/span> e<\/span>:<\/span>\r\n    print<\/span>(<\/span>e<\/span>.<\/span>value<\/span>)<\/span>\r\n# 1<\/span><\/code><\/pre>\n<\/div>\n
\u901a\u8fc7\u4e0a\u9762\u7684\u65b9\u5f0f\u6765\u65b0\u5efa\u4e00\u4e2arun\u51fd\u6570\u6765\u9a71\u52a8\u534f\u7a0b\u51fd\u6570\uff1a<\/p>\n
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def<\/span> run<\/span>(<\/span>coroutine<\/span>):<\/span>\r\n    try<\/span>:<\/span>\r\n        coroutine<\/span>.<\/span>send<\/span>(<\/span>None<\/span>)<\/span>\r\n    except<\/span> StopIteration<\/span> as<\/span> e<\/span>:<\/span>\r\n        return<\/span> e<\/span>.<\/span>value<\/span><\/code><\/pre>\n<\/div>\n
\u5728\u534f\u7a0b\u51fd\u6570\u4e2d\uff0c\u53ef\u4ee5\u901a\u8fc7await\u8bed\u6cd5\u6765\u6302\u8d77\u81ea\u8eab\u7684\u534f\u7a0b\uff0c\u5e76\u7b49\u5f85\u53e6\u4e00\u4e2a\u534f\u7a0b\u5b8c\u6210\u76f4\u5230\u8fd4\u56de\u7ed3\u679c\uff1a<\/p>\n
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async<\/span> def<\/span> async_function<\/span>():<\/span>\r\n    return<\/span> 1<\/span>\r\n\r\nasync<\/span> def<\/span> await_coroutine<\/span>():<\/span>\r\n    result<\/span> =<\/span> await<\/span> async_function<\/span>()<\/span>\r\n    print<\/span>(<\/span>result<\/span>)<\/span>\r\n    \r\nrun<\/span>(<\/span>await_coroutine<\/span>())<\/span>\r\n# 1<\/span><\/code><\/pre>\n<\/div>\n
\u8981\u6ce8\u610f\u7684\u662f\uff0cawait\u8bed\u6cd5\u53ea\u80fd\u51fa\u73b0\u5728\u901a\u8fc7async\u4fee\u9970\u7684\u51fd\u6570\u4e2d\uff0c\u5426\u5219\u4f1a\u62a5SyntaxError\u9519\u8bef\u3002<\/p>\n
\u800c\u4e14await\u540e\u9762\u7684\u5bf9\u8c61\u9700\u8981\u662f\u4e00\u4e2aAwaitable\uff0c\u6216\u8005\u5b9e\u73b0\u4e86\u76f8\u5173\u7684\u534f\u8bae\u3002<\/p>\n
\u67e5\u770bAwaitable\u62bd\u8c61\u7c7b\u7684\u4ee3\u7801\uff0c\u8868\u660e\u4e86\u53ea\u8981\u4e00\u4e2a\u7c7b\u5b9e\u73b0\u4e86__await__\u65b9\u6cd5\uff0c\u90a3\u4e48\u901a\u8fc7\u5b83\u6784\u9020\u51fa\u6765\u7684\u5b9e\u4f8b\u5c31\u662f\u4e00\u4e2aAwaitable\uff1a<\/p>\n
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class<\/span> Awaitable<\/span>(<\/span>metaclass<\/span>=<\/span>ABCMeta<\/span>):<\/span>\r\n    __slots__<\/span> =<\/span> ()<\/span>\r\n\r\n    @abstractmethod<\/span>\r\n    def<\/span> __await__<\/span>(<\/span>self<\/span>):<\/span>\r\n        yield<\/span>\r\n\r\n    @classmethod<\/span>\r\n    def<\/span> __subclasshook__<\/span>(<\/span>cls<\/span>,<\/span> C<\/span>):<\/span>\r\n        if<\/span> cls<\/span> is<\/span> Awaitable<\/span>:<\/span>\r\n            return<\/span> _check_methods<\/span>(<\/span>C<\/span>,<\/span> \"__await__\"<\/span>)<\/span>\r\n        return<\/span> NotImplemented<\/span><\/code><\/pre>\n<\/div>\n
\u800c\u4e14\u53ef\u4ee5\u770b\u5230\uff0cCoroutine\u7c7b\u4e5f\u7ee7\u627f\u4e86Awaitable\uff0c\u800c\u4e14\u5b9e\u73b0\u4e86send\uff0cthrow\u548cclose\u65b9\u6cd5\u3002\u6240\u4ee5await\u4e00\u4e2a\u8c03\u7528\u5f02\u6b65\u51fd\u6570\u8fd4\u56de\u7684\u534f\u7a0b\u5bf9\u8c61\u662f\u5408\u6cd5\u7684\u3002<\/p>\n
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class<\/span> Coroutine<\/span>(<\/span>Awaitable<\/span>):<\/span>\r\n    __slots__<\/span> =<\/span> ()<\/span>\r\n\r\n    @abstractmethod<\/span>\r\n    def<\/span> send<\/span>(<\/span>self<\/span>,<\/span> value<\/span>):<\/span>\r\n        ...<\/span>\r\n\r\n    @abstractmethod<\/span>\r\n    def<\/span> throw<\/span>(<\/span>self<\/span>,<\/span> typ<\/span>,<\/span> val<\/span>=<\/span>None<\/span>,<\/span> tb<\/span>=<\/span>None<\/span>):<\/span>\r\n        ...<\/span>\r\n\r\n    def<\/span> close<\/span>(<\/span>self<\/span>):<\/span>\r\n        ...<\/span>\r\n        \r\n    @classmethod<\/span>\r\n    def<\/span> __subclasshook__<\/span>(<\/span>cls<\/span>,<\/span> C<\/span>):<\/span>\r\n        if<\/span> cls<\/span> is<\/span> Coroutine<\/span>:<\/span>\r\n            return<\/span> _check_methods<\/span>(<\/span>C<\/span>,<\/span> '__await__'<\/span>,<\/span> 'send'<\/span>,<\/span> 'throw'<\/span>,<\/span> 'close'<\/span>)<\/span>\r\n        return<\/span> NotImplemented<\/span><\/code><\/pre>\n<\/div>\n
\u63a5\u4e0b\u6765\u662f\u5f02\u6b65\u751f\u6210\u5668\uff0c\u6765\u770b\u4e00\u4e2a\u4f8b\u5b50\uff1a<\/p>\n
\u5047\u5982\u6211\u8981\u5230\u4e00\u5bb6\u8d85\u5e02\u53bb\u8d2d\u4e70\u571f\u8c46\uff0c\u800c\u8d85\u5e02\u8d27\u67b6\u4e0a\u7684\u571f\u8c46\u6570\u91cf\u662f\u6709\u9650\u7684\uff1a<\/p>\n
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class<\/span> Potato<\/span>:<\/span>\r\n    @classmethod<\/span>\r\n    def<\/span> make<\/span>(<\/span>cls<\/span>,<\/span> num<\/span>,<\/span> *<\/span>args<\/span>,<\/span> **<\/span>kws<\/span>):<\/span>\r\n        potatos<\/span> =<\/span> []<\/span>\r\n        for<\/span> i<\/span> in<\/span> range<\/span>(<\/span>num<\/span>):<\/span>\r\n            potatos<\/span>.<\/span>append<\/span>(<\/span>cls<\/span>.<\/span>__new__<\/span>(<\/span>cls<\/span>,<\/span> *<\/span>args<\/span>,<\/span> **<\/span>kws<\/span>))<\/span>\r\n        return<\/span> potatos<\/span>\r\n\r\nall_potatos<\/span> =<\/span> Potato<\/span>.<\/span>make<\/span>(<\/span>5<\/span>)<\/span><\/code><\/pre>\n<\/div>\n
\u73b0\u5728\u6211\u60f3\u8981\u4e7050\u4e2a\u571f\u8c46\uff0c\u6bcf\u6b21\u4ece\u8d27\u67b6\u4e0a\u62ff\u8d70\u4e00\u4e2a\u571f\u8c46\u653e\u5230\u7bee\u5b50\uff1a<\/p>\n
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def<\/span> take_potatos<\/span>(<\/span>num<\/span>):<\/span>\r\n    count<\/span> =<\/span> 0<\/span>\r\n    while<\/span> True<\/span>:<\/span>\r\n        if<\/span> len<\/span>(<\/span>all_potatos<\/span>)<\/span> ==<\/span> 0<\/span>:<\/span>\r\n            sleep<\/span>(<\/span>.<\/span>1<\/span>)<\/span>\r\n        else<\/span>:<\/span>\r\n            potato<\/span> =<\/span> all_potatos<\/span>.<\/span>pop<\/span>()<\/span>\r\n            yield<\/span> potato<\/span>\r\n            count<\/span> +=<\/span> 1<\/span>\r\n            if<\/span> count<\/span> ==<\/span> num<\/span>:<\/span>\r\n                break<\/span>\r\n\r\ndef<\/span> buy_potatos<\/span>():<\/span>\r\n    bucket<\/span> =<\/span> []<\/span>\r\n    for<\/span> p<\/span> in<\/span> take_potatos<\/span>(<\/span>50<\/span>):<\/span>\r\n        bucket<\/span>.<\/span>append<\/span>(<\/span>p<\/span>)<\/span><\/code><\/pre>\n<\/div>\n
\u5bf9\u5e94\u5230\u4ee3\u7801\u4e2d\uff0c\u5c31\u662f\u8fed\u4ee3\u4e00\u4e2a\u751f\u6210\u5668\u7684\u6a21\u578b\uff0c\u663e\u7136\uff0c\u5f53\u8d27\u67b6\u4e0a\u7684\u571f\u8c46\u4e0d\u591f\u7684\u65f6\u5019\uff0c\u8fd9\u65f6\u53ea\u80fd\u591f\u6b7b\u7b49\uff0c\u800c\u4e14\u5728\u4e0a\u9762\u4f8b\u5b50\u4e2d\u7b49\u591a\u957f\u65f6\u95f4\u90fd\u4e0d\u4f1a\u6709\u7ed3\u679c\uff08\u56e0\u4e3a\u4e00\u5207\u90fd\u662f\u540c\u6b65\u7684\uff09\uff0c\u4e5f\u8bb8\u53ef\u4ee5\u7528\u591a\u8fdb\u7a0b\u548c\u591a\u7ebf\u7a0b\u89e3\u51b3\uff0c\u800c\u5728\u73b0\u5b9e\u751f\u6d3b\u4e2d\uff0c\u66f4\u5e94\u8be5\u50cf\u662f\u8fd9\u6837\u7684\uff1a<\/p>\n
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async<\/span> def<\/span> take_potatos<\/span>(<\/span>num<\/span>):<\/span>\r\n    count<\/span> =<\/span> 0<\/span>\r\n    while<\/span> True<\/span>:<\/span>\r\n        if<\/span> len<\/span>(<\/span>all_potatos<\/span>)<\/span> ==<\/span> 0<\/span>:<\/span>\r\n            await<\/span> ask_for_potato<\/span>()<\/span>\r\n        potato<\/span> =<\/span> all_potatos<\/span>.<\/span>pop<\/span>()<\/span>\r\n        yield<\/span> potato<\/span>\r\n        count<\/span> +=<\/span> 1<\/span>\r\n        if<\/span> count<\/span> ==<\/span> num<\/span>:<\/span>\r\n            break<\/span><\/code><\/pre>\n<\/div>\n
\u5f53\u8d27\u67b6\u4e0a\u7684\u571f\u8c46\u6ca1\u6709\u4e86\u4e4b\u540e\uff0c\u6211\u53ef\u4ee5\u8be2\u95ee\u8d85\u5e02\u8bf7\u6c42\u9700\u8981\u66f4\u591a\u7684\u571f\u8c46\uff0c\u8fd9\u65f6\u5019\u9700\u8981\u7b49\u5f85\u4e00\u6bb5\u65f6\u95f4\u76f4\u5230\u751f\u4ea7\u8005\u5b8c\u6210\u751f\u4ea7\u7684\u8fc7\u7a0b\uff1a<\/p>\n
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async<\/span> def<\/span> ask_for_potato<\/span>():<\/span>\r\n    await<\/span> asyncio<\/span>.<\/span>sleep<\/span>(<\/span>random<\/span>.<\/span>random<\/span>())<\/span>\r\n    all_potatos<\/span>.<\/span>extend<\/span>(<\/span>Potato<\/span>.<\/span>make<\/span>(<\/span>random<\/span>.<\/span>randint<\/span>(<\/span>1<\/span>,<\/span> 10<\/span>)))<\/span><\/code><\/pre>\n<\/div>\n
\u5f53\u751f\u4ea7\u8005\u5b8c\u6210\u548c\u8fd4\u56de\u4e4b\u540e\uff0c\u8fd9\u662f\u4fbf\u80fd\u4eceawait\u6302\u8d77\u7684\u5730\u65b9\u7ee7\u7eed\u5f80\u4e0b\u8dd1\uff0c\u5b8c\u6210\u6d88\u8d39\u7684\u8fc7\u7a0b\u3002\u800c\u8fd9\u6574\u4e00\u4e2a\u8fc7\u7a0b\uff0c\u5c31\u662f\u4e00\u4e2a\u5f02\u6b65\u751f\u6210\u5668\u8fed\u4ee3\u7684\u6d41\u7a0b\uff1a<\/p>\n
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async<\/span> def<\/span> buy_potatos<\/span>():<\/span>\r\n    bucket<\/span> =<\/span> []<\/span>\r\n    async<\/span> for<\/span> p<\/span> in<\/span> take_potatos<\/span>(<\/span>50<\/span>):<\/span>\r\n        bucket<\/span>.<\/span>append<\/span>(<\/span>p<\/span>)<\/span>\r\n        print<\/span>(<\/span>f<\/span>'Got potato {id(p)}...'<\/span>)<\/span><\/code><\/pre>\n<\/div>\n
async for\u8bed\u6cd5\u8868\u793a\u6211\u4eec\u8981\u540e\u9762\u8fed\u4ee3\u7684\u662f\u4e00\u4e2a\u5f02\u6b65\u751f\u6210\u5668\u3002<\/p>\n
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def<\/span> main<\/span>():<\/span>\r\n    import<\/span> asyncio<\/span>\r\n    loop<\/span> =<\/span> asyncio<\/span>.<\/span>get_event_loop<\/span>()<\/span>\r\n    res<\/span> =<\/span> loop<\/span>.<\/span>run_until_complete<\/span>(<\/span>buy_potatos<\/span>())<\/span>\r\n    loop<\/span>.<\/span>close<\/span>()<\/span><\/code><\/pre>\n<\/div>\n
\u7528asyncio\u8fd0\u884c\u8fd9\u6bb5\u4ee3\u7801\uff0c\u7ed3\u679c\u662f\u8fd9\u6837\u7684\uff1a<\/p>\n
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Got<\/span> potato<\/span> 4338641384.<\/span>..<\/span>\r\nGot<\/span> potato<\/span> 4338641160.<\/span>..<\/span>\r\nGot<\/span> potato<\/span> 4338614736.<\/span>..<\/span>\r\nGot<\/span> potato<\/span> 4338614680.<\/span>..<\/span>\r\nGot<\/span> potato<\/span> 4338614568.<\/span>..<\/span>\r\nGot<\/span> potato<\/span> 4344861864.<\/span>..<\/span>\r\nGot<\/span> potato<\/span> 4344843456.<\/span>..<\/span>\r\nGot<\/span> potato<\/span> 4344843400.<\/span>..<\/span>\r\nGot<\/span> potato<\/span> 4338641384.<\/span>..<\/span>\r\nGot<\/span> potato<\/span> 4338641160.<\/span>..<\/span>\r\n...<\/span><\/code><\/pre>\n<\/div>\n
\u65e2\u7136\u662f\u5f02\u6b65\u7684\uff0c\u5728\u8bf7\u6c42\u4e4b\u540e\u4e0d\u4e00\u5b9a\u8981\u6b7b\u7b49\uff0c\u800c\u662f\u53ef\u4ee5\u505a\u5176\u4ed6\u4e8b\u60c5\u3002\u6bd4\u5982\u9664\u4e86\u571f\u8c46\uff0c\u6211\u8fd8\u60f3\u4e70\u756a\u8304\uff0c\u8fd9\u65f6\u53ea\u9700\u8981\u5728\u4e8b\u4ef6\u5faa\u73af\u4e2d\u518d\u6dfb\u52a0\u4e00\u4e2a\u8fc7\u7a0b\uff1a<\/p>\n
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def<\/span> main<\/span>():<\/span>\r\n    import<\/span> asyncio<\/span>\r\n    loop<\/span> =<\/span> asyncio<\/span>.<\/span>get_event_loop<\/span>()<\/span>\r\n    res<\/span> =<\/span> loop<\/span>.<\/span>run_until_complete<\/span>(<\/span>asyncio<\/span>.<\/span>wait<\/span>([<\/span>buy_potatos<\/span>(),<\/span> buy_tomatos<\/span>()]))<\/span>\r\n    loop<\/span>.<\/span>close<\/span>()<\/span><\/code><\/pre>\n<\/div>\n
\u518d\u6765\u8fd0\u884c\u8fd9\u6bb5\u4ee3\u7801\uff1a<\/p>\n
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Got<\/span> potato<\/span> 4423119312.<\/span>..<\/span>\r\nGot<\/span> tomato<\/span> 4423119368.<\/span>..<\/span>\r\nGot<\/span> potato<\/span> 4429291024.<\/span>..<\/span>\r\nGot<\/span> potato<\/span> 4421640768.<\/span>..<\/span>\r\nGot<\/span> tomato<\/span> 4429331704.<\/span>..<\/span>\r\nGot<\/span> tomato<\/span> 4429331760.<\/span>..<\/span>\r\nGot<\/span> tomato<\/span> 4423119368.<\/span>..<\/span>\r\nGot<\/span> potato<\/span> 4429331760.<\/span>..<\/span>\r\nGot<\/span> potato<\/span> 4429331704.<\/span>..<\/span>\r\nGot<\/span> potato<\/span> 4429346688.<\/span>..<\/span>\r\nGot<\/span> potato<\/span> 4429346072.<\/span>..<\/span>\r\nGot<\/span> tomato<\/span> 4429347360.<\/span>..<\/span>\r\n...<\/span><\/code><\/pre>\n<\/div>\n
\u770b\u4e0bAsyncGenerator\u7684\u5b9a\u4e49\uff0c\u5b83\u9700\u8981\u5b9e\u73b0__aiter__\u548c__anext__\u4e24\u4e2a\u6838\u5fc3\u65b9\u6cd5\uff0c\u4ee5\u53caasend\uff0cathrow\uff0caclose\u65b9\u6cd5\u3002<\/p>\n
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class<\/span> AsyncGenerator<\/span>(<\/span>AsyncIterator<\/span>):<\/span>\r\n    __slots__<\/span> =<\/span> ()<\/span>\r\n\r\n    async<\/span> def<\/span> __anext__<\/span>(<\/span>self<\/span>):<\/span>\r\n        ...<\/span>\r\n\r\n    @abstractmethod<\/span>\r\n    async<\/span> def<\/span> asend<\/span>(<\/span>self<\/span>,<\/span> value<\/span>):<\/span>\r\n        ...<\/span>\r\n\r\n    @abstractmethod<\/span>\r\n    async<\/span> def<\/span> athrow<\/span>(<\/span>self<\/span>,<\/span> typ<\/span>,<\/span> val<\/span>=<\/span>None<\/span>,<\/span> tb<\/span>=<\/span>None<\/span>):<\/span>\r\n        ...<\/span>\r\n\r\n    async<\/span> def<\/span> aclose<\/span>(<\/span>self<\/span>):<\/span>\r\n        ...<\/span>\r\n\r\n    @classmethod<\/span>\r\n    def<\/span> __subclasshook__<\/span>(<\/span>cls<\/span>,<\/span> C<\/span>):<\/span>\r\n        if<\/span> cls<\/span> is<\/span> AsyncGenerator<\/span>:<\/span>\r\n            return<\/span> _check_methods<\/span>(<\/span>C<\/span>,<\/span> '__aiter__'<\/span>,<\/span> '__anext__'<\/span>,<\/span>\r\n                                  'asend'<\/span>,<\/span> 'athrow'<\/span>,<\/span> 'aclose'<\/span>)<\/span>\r\n        return<\/span> NotImplemented<\/span><\/code><\/pre>\n<\/div>\n
\u5f02\u6b65\u751f\u6210\u5668\u662f\u57283.6\u4e4b\u540e\u624d\u6709\u7684\u7279\u6027\uff0c\u540c\u6837\u7684\u8fd8\u6709\u5f02\u6b65\u63a8\u5bfc\u8868\u8fbe\u5f0f\uff0c\u56e0\u6b64\u5728\u4e0a\u9762\u7684\u4f8b\u5b50\u4e2d\uff0c\u4e5f\u53ef\u4ee5\u5199\u6210\u8fd9\u6837\uff1a<\/p>\n
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bucket<\/span> =<\/span> [<\/span>p<\/span> async<\/span> for<\/span> p<\/span> in<\/span> take_potatos<\/span>(<\/span>50<\/span>)]<\/span><\/code><\/pre>\n<\/div>\n
\u7c7b\u4f3c\u7684\uff0c\u8fd8\u6709await\u8868\u8fbe\u5f0f\uff1a<\/p>\n
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result<\/span> =<\/span> [<\/span>await<\/span> fun<\/span>()<\/span> for<\/span> fun<\/span> in<\/span> funcs<\/span> if<\/span> await<\/span> condition<\/span>()]<\/span><\/code><\/pre>\n<\/div>\n
\u9664\u4e86\u51fd\u6570\u4e4b\u5916\uff0c\u7c7b\u5b9e\u4f8b\u7684\u666e\u901a\u65b9\u6cd5\u4e5f\u80fd\u7528async\u8bed\u6cd5\u4fee\u9970\uff1a<\/p>\n
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class<\/span> ThreeTwoOne<\/span>:<\/span>\r\n    async<\/span> def<\/span> begin<\/span>(<\/span>self<\/span>):<\/span>\r\n        print<\/span>(<\/span>3<\/span>)<\/span>\r\n        await<\/span> asyncio<\/span>.<\/span>sleep<\/span>(<\/span>1<\/span>)<\/span>\r\n        print<\/span>(<\/span>2<\/span>)<\/span>\r\n        await<\/span> asyncio<\/span>.<\/span>sleep<\/span>(<\/span>1<\/span>)<\/span>\r\n        print<\/span>(<\/span>1<\/span>)<\/span>        \r\n        await<\/span> asyncio<\/span>.<\/span>sleep<\/span>(<\/span>1<\/span>)<\/span>\r\n        return<\/span>\r\n\r\nasync<\/span> def<\/span> game<\/span>():<\/span>\r\n    t<\/span> =<\/span> ThreeTwoOne<\/span>()<\/span>\r\n    await<\/span> t<\/span>.<\/span>begin<\/span>()<\/span>\r\n    print<\/span>(<\/span>'start'<\/span>)<\/span><\/code><\/pre>\n<\/div>\n
\u5b9e\u4f8b\u65b9\u6cd5\u7684\u8c03\u7528\u540c\u6837\u662f\u8fd4\u56de\u4e00\u4e2acoroutine\uff1a<\/p>\n
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function<\/span> =<\/span> ThreeTwoOne<\/span>.<\/span>begin<\/span>\r\nmethod<\/span> =<\/span> function<\/span>.<\/span>__get__<\/span>(<\/span>ThreeTwoOne<\/span>,<\/span> ThreeTwoOne<\/span>())<\/span>\r\nimport<\/span> inspect<\/span>\r\nassert<\/span> inspect<\/span>.<\/span>isfunction<\/span>(<\/span>function<\/span>)<\/span>\r\nassert<\/span> inspect<\/span>.<\/span>ismethod<\/span>(<\/span>method<\/span>)<\/span>\r\nassert<\/span> inspect<\/span>.<\/span>iscoroutine<\/span>(<\/span>method<\/span>())<\/span><\/code><\/pre>\n<\/div>\n
\u540c\u7406\u8fd8\u6709\u7c7b\u65b9\u6cd5\uff1a<\/p>\n
\n
class<\/span> ThreeTwoOne<\/span>:<\/span>\r\n    @classmethod<\/span>\r\n    async<\/span> def<\/span> begin<\/span>(<\/span>cls<\/span>):<\/span>\r\n        print<\/span>(<\/span>3<\/span>)<\/span>\r\n        await<\/span> asyncio<\/span>.<\/span>sleep<\/span>(<\/span>1<\/span>)<\/span>\r\n        print<\/span>(<\/span>2<\/span>)<\/span>\r\n        await<\/span> asyncio<\/span>.<\/span>sleep<\/span>(<\/span>1<\/span>)<\/span>\r\n        print<\/span>(<\/span>1<\/span>)<\/span>        \r\n        await<\/span> asyncio<\/span>.<\/span>sleep<\/span>(<\/span>1<\/span>)<\/span>\r\n        return<\/span>\r\n\r\nasync<\/span> def<\/span> game<\/span>():<\/span>\r\n    await<\/span> ThreeTwoOne<\/span>.<\/span>begin<\/span>()<\/span>\r\n    print<\/span>(<\/span>'start'<\/span>)<\/span><\/code><\/pre>\n<\/div>\n
\u6839\u636ePEP 492\u4e2d\uff0casync\u4e5f\u53ef\u4ee5\u5e94\u7528\u5230\u4e0a\u4e0b\u6587\u7ba1\u7406\u5668\u4e2d\uff0c__aenter__\u548c__aexit__\u9700\u8981\u8fd4\u56de\u4e00\u4e2aAwaitable\uff1a<\/p>\n
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class<\/span> GameContext<\/span>:<\/span>\r\n    async<\/span> def<\/span> __aenter__<\/span>(<\/span>self<\/span>):<\/span>\r\n        print<\/span>(<\/span>'game loading...'<\/span>)<\/span>\r\n        await<\/span> asyncio<\/span>.<\/span>sleep<\/span>(<\/span>1<\/span>)<\/span>\r\n\r\n    async<\/span> def<\/span> __aexit__<\/span>(<\/span>self<\/span>,<\/span> exc_type<\/span>,<\/span> exc<\/span>,<\/span> tb<\/span>):<\/span>\r\n        print<\/span>(<\/span>'game exit...'<\/span>)<\/span>\r\n        await<\/span> asyncio<\/span>.<\/span>sleep<\/span>(<\/span>1<\/span>)<\/span>\r\n\r\nasync<\/span> def<\/span> game<\/span>():<\/span>\r\n    async<\/span> with<\/span> GameContext<\/span>():<\/span>\r\n        print<\/span>(<\/span>'game start...'<\/span>)<\/span>\r\n        await<\/span> asyncio<\/span>.<\/span>sleep<\/span>(<\/span>2<\/span>)<\/span><\/code><\/pre>\n<\/div>\n
\u57283.7\u7248\u672c\uff0ccontextlib\u4e2d\u4f1a\u65b0\u589e\u4e00\u4e2aasynccontextmanager\u88c5\u9970\u5668\u6765\u5305\u88c5\u4e00\u4e2a\u5b9e\u73b0\u5f02\u6b65\u534f\u8bae\u7684\u4e0a\u4e0b\u6587\u7ba1\u7406\u5668\uff1a<\/p>\n
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from<\/span> contextlib<\/span> import<\/span> asynccontextmanager<\/span>\r\n\r\n@asynccontextmanager<\/span>\r\nasync<\/span> def<\/span> get_connection<\/span>():<\/span>\r\n    conn<\/span> =<\/span> await<\/span> acquire_db_connection<\/span>()<\/span>\r\n    try<\/span>:<\/span>\r\n        yield<\/span>\r\n    finally<\/span>:<\/span>\r\n        await<\/span> release_db_connection<\/span>(<\/span>conn<\/span>)<\/span><\/code><\/pre>\n<\/div>\n
async\u4fee\u9970\u7b26\u4e5f\u80fd\u7528\u5728__call__\u65b9\u6cd5\u4e0a\uff1a<\/p>\n
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class<\/span> GameContext<\/span>:<\/span>\r\n    async<\/span> def<\/span> __aenter__<\/span>(<\/span>self<\/span>):<\/span>\r\n        self<\/span>.<\/span>_started<\/span> =<\/span> time<\/span>()<\/span>\r\n        print<\/span>(<\/span>'game loading...'<\/span>)<\/span>\r\n        await<\/span> asyncio<\/span>.<\/span>sleep<\/span>(<\/span>1<\/span>)<\/span>\r\n        return<\/span> self<\/span>\r\n\r\n    async<\/span> def<\/span> __aexit__<\/span>(<\/span>self<\/span>,<\/span> exc_type<\/span>,<\/span> exc<\/span>,<\/span> tb<\/span>):<\/span>\r\n        print<\/span>(<\/span>'game exit...'<\/span>)<\/span>\r\n        await<\/span> asyncio<\/span>.<\/span>sleep<\/span>(<\/span>1<\/span>)<\/span>\r\n\r\n    async<\/span> def<\/span> __call__<\/span>(<\/span>self<\/span>,<\/span> *<\/span>args<\/span>,<\/span> **<\/span>kws<\/span>):<\/span>\r\n        if<\/span> args<\/span>[<\/span>0<\/span>]<\/span> ==<\/span> 'time'<\/span>:<\/span>\r\n            return<\/span> time<\/span>()<\/span> -<\/span> self<\/span>.<\/span>_started<\/span>\r\n\r\nasync<\/span> def<\/span> game<\/span>():<\/span>\r\n    async<\/span> with<\/span> GameContext<\/span>()<\/span> as<\/span> ctx<\/span>:<\/span>\r\n        print<\/span>(<\/span>'game start...'<\/span>)<\/span>\r\n        await<\/span> asyncio<\/span>.<\/span>sleep<\/span>(<\/span>2<\/span>)<\/span>\r\n        print<\/span>(<\/span>'game time: '<\/span>,<\/span> await<\/span> ctx<\/span>(<\/span>'time'<\/span>))<\/span><\/code><\/pre>\n<\/div>\n
await\u548cyield from<\/strong><\/p>\n
Python3.3\u7684yield from\u8bed\u6cd5\u53ef\u4ee5\u628a\u751f\u6210\u5668\u7684\u64cd\u4f5c\u59d4\u6258\u7ed9\u53e6\u4e00\u4e2a\u751f\u6210\u5668\uff0c\u751f\u6210\u5668\u7684\u8c03\u7528\u65b9\u53ef\u4ee5\u76f4\u63a5\u4e0e\u5b50\u751f\u6210\u5668\u8fdb\u884c\u901a\u4fe1\uff1a<\/p>\n
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def<\/span> sub_gen<\/span>():<\/span>\r\n    yield<\/span> 1<\/span>\r\n    yield<\/span> 2<\/span>\r\n    yield<\/span> 3<\/span>\r\n\r\ndef<\/span> gen<\/span>():<\/span>\r\n    return<\/span> (<\/span>yield<\/span> from<\/span> sub_gen<\/span>())<\/span>\r\n\r\ndef<\/span> main<\/span>():<\/span>\r\n    for<\/span> val<\/span> in<\/span> gen<\/span>():<\/span>\r\n        print<\/span>(<\/span>val<\/span>)<\/span>\r\n# 1<\/span>\r\n# 2<\/span>\r\n# 3<\/span><\/code><\/pre>\n<\/div>\n
\u5229\u7528\u8fd9\u4e00\u7279\u6027\uff0c\u4f7f\u7528yield from\u80fd\u591f\u7f16\u5199\u51fa\u7c7b\u4f3c\u534f\u7a0b\u6548\u679c\u7684\u51fd\u6570\u8c03\u7528\uff0c\u57283.5\u4e4b\u524d\uff0casyncio\u6b63\u662f\u4f7f\u7528@asyncio.coroutine\u548cyield from\u8bed\u6cd5\u6765\u521b\u5efa\u534f\u7a0b\uff1a<\/p>\n
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# https:\/\/docs.python.org\/3.4\/library\/asyncio-task.html<\/span>\r\nimport<\/span> asyncio<\/span>\r\n\r\n@asyncio.coroutine<\/span>\r\ndef<\/span> compute<\/span>(<\/span>x<\/span>,<\/span> y<\/span>):<\/span>\r\n    print<\/span>(<\/span>\"Compute <\/span>%s<\/span> + <\/span>%s<\/span> ...\"<\/span> %<\/span> (<\/span>x<\/span>,<\/span> y<\/span>))<\/span>\r\n    yield<\/span> from<\/span> asyncio.sleep<\/span>(<\/span>1.0<\/span>)<\/span>\r\n    return<\/span> x<\/span> +<\/span> y<\/span>\r\n\r\n@asyncio.coroutine<\/span>\r\ndef<\/span> print_sum<\/span>(<\/span>x<\/span>,<\/span> y<\/span>):<\/span>\r\n    result<\/span> =<\/span> yield<\/span> from<\/span> compute<\/span>(<\/span>x<\/span>,<\/span> y<\/span>)<\/span>\r\n    print<\/span>(<\/span>\"<\/span>%s<\/span> + <\/span>%s<\/span> = <\/span>%s<\/span>\"<\/span> %<\/span> (<\/span>x<\/span>,<\/span> y<\/span>,<\/span> result<\/span>))<\/span>\r\n\r\nloop<\/span> =<\/span> asyncio<\/span>.<\/span>get_event_loop<\/span>()<\/span>\r\nloop<\/span>.<\/span>run_until_complete<\/span>(<\/span>print_sum<\/span>(<\/span>1<\/span>,<\/span> 2<\/span>))<\/span>\r\nloop<\/span>.<\/span>close<\/span>()<\/span><\/code><\/pre>\n<\/div>\n
\u7136\u800c\uff0c\u7528yield from\u5bb9\u6613\u5728\u8868\u793a\u534f\u7a0b\u548c\u751f\u6210\u5668\u4e2d\u6df7\u6dc6\uff0c\u6ca1\u6709\u826f\u597d\u7684\u8bed\u4e49\u6027\uff0c\u6240\u4ee5\u5728Python 3.5\u63a8\u51fa\u4e86\u66f4\u65b0\u7684async\/await\u8868\u8fbe\u5f0f\u6765\u4f5c\u4e3a\u534f\u7a0b\u7684\u8bed\u6cd5\u3002<\/p>\n
\u56e0\u6b64\u7c7b\u4f3c\u4ee5\u4e0b\u7684\u8c03\u7528\u662f\u7b49\u4ef7\u7684\uff1a<\/p>\n
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async<\/span> with<\/span> lock<\/span>:<\/span>\r\n    ...<\/span>\r\n    \r\nwith<\/span> (<\/span>yield<\/span> from<\/span> lock<\/span>):<\/span>\r\n    ...<\/span>\r\n######################<\/span>\r\ndef<\/span> main<\/span>():<\/span>\r\n    return<\/span> (<\/span>yield<\/span> from<\/span> coro<\/span>())<\/span>\r\n\r\ndef<\/span> main<\/span>():<\/span>\r\n    return<\/span> (<\/span>await<\/span> coro<\/span>())<\/span><\/code><\/pre>\n<\/div>\n
\u90a3\u4e48\uff0c\u600e\u4e48\u628a\u751f\u6210\u5668\u5305\u88c5\u4e3a\u4e00\u4e2a\u534f\u7a0b\u5bf9\u8c61\u5462\uff1f\u8fd9\u65f6\u5019\u53ef\u4ee5\u7528\u5230types\u5305\u4e2d\u7684coroutine\u88c5\u9970\u5668\uff08\u5982\u679c\u4f7f\u7528asyncio\u505a\u9a71\u52a8\u7684\u8bdd\uff0c\u90a3\u4e48\u4e5f\u53ef\u4ee5\u4f7f\u7528asyncio\u7684coroutine\u88c5\u9970\u5668\uff09\uff0c@types.coroutine\u88c5\u9970\u5668\u4f1a\u5c06\u4e00\u4e2a\u751f\u6210\u5668\u51fd\u6570\u5305\u88c5\u4e3a\u534f\u7a0b\u5bf9\u8c61\uff1a<\/p>\n
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import<\/span> asyncio<\/span>\r\nimport<\/span> types<\/span>\r\n\r\n@types.coroutine<\/span>\r\ndef<\/span> compute<\/span>(<\/span>x<\/span>,<\/span> y<\/span>):<\/span>\r\n    print<\/span>(<\/span>\"Compute <\/span>%s<\/span> + <\/span>%s<\/span> ...\"<\/span> %<\/span> (<\/span>x<\/span>,<\/span> y<\/span>))<\/span>\r\n    yield<\/span> from<\/span> asyncio.sleep<\/span>(<\/span>1.0<\/span>)<\/span>\r\n    return<\/span> x<\/span> +<\/span> y<\/span>\r\n\r\nasync<\/span> def<\/span> print_sum<\/span>(<\/span>x<\/span>,<\/span> y<\/span>):<\/span>\r\n    result<\/span> =<\/span> await<\/span> compute<\/span>(<\/span>x<\/span>,<\/span> y<\/span>)<\/span>\r\n    print<\/span>(<\/span>\"<\/span>%s<\/span> + <\/span>%s<\/span> = <\/span>%s<\/span>\"<\/span> %<\/span> (<\/span>x<\/span>,<\/span> y<\/span>,<\/span> result<\/span>))<\/span>\r\n\r\nloop<\/span> =<\/span> asyncio<\/span>.<\/span>get_event_loop<\/span>()<\/span>\r\nloop<\/span>.<\/span>run_until_complete<\/span>(<\/span>print_sum<\/span>(<\/span>1<\/span>,<\/span> 2<\/span>))<\/span>\r\nloop<\/span>.<\/span>close<\/span>()<\/span><\/code><\/pre>\n<\/div>\n
\u5c3d\u7ba1\u4e24\u4e2a\u51fd\u6570\u5206\u522b\u4f7f\u7528\u4e86\u65b0\u65e7\u8bed\u6cd5\uff0c\u4f46\u4ed6\u4eec\u90fd\u662f\u534f\u7a0b\u5bf9\u8c61\uff0c\u4e5f\u5206\u522b\u79f0\u4f5cnative coroutine<\/em>\u4ee5\u53cagenerator-based coroutine<\/em>\uff0c\u56e0\u6b64\u4e0d\u7528\u62c5\u5fc3\u8bed\u6cd5\u95ee\u9898\u3002<\/p>\n
\u4e0b\u9762\u89c2\u5bdf\u4e00\u4e2aasyncio\u4e2dFuture\u7684\u4f8b\u5b50\uff1a<\/p>\n
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import<\/span> asyncio<\/span>\r\n\r\nfuture<\/span> =<\/span> asyncio<\/span>.<\/span>Future<\/span>()<\/span>\r\n\r\nasync<\/span> def<\/span> coro1<\/span>():<\/span>\r\n    await<\/span> asyncio<\/span>.<\/span>sleep<\/span>(<\/span>1<\/span>)<\/span>\r\n    future<\/span>.<\/span>set_result<\/span>(<\/span>'data'<\/span>)<\/span>\r\n\r\nasync<\/span> def<\/span> coro2<\/span>():<\/span>\r\n    print<\/span>(<\/span>await<\/span> future<\/span>)<\/span>\r\n\r\nloop<\/span> =<\/span> asyncio<\/span>.<\/span>get_event_loop<\/span>()<\/span>\r\nloop<\/span>.<\/span>run_until_complete<\/span>(<\/span>asyncio<\/span>.<\/span>wait<\/span>([<\/span>\r\n    coro1<\/span>(),<\/span> \r\n    coro2<\/span>()<\/span>\r\n]))<\/span>\r\nloop<\/span>.<\/span>close<\/span>()<\/span><\/code><\/pre>\n<\/div>\n
\u4e24\u4e2a\u534f\u7a0b\u5728\u5728\u4e8b\u4ef6\u5faa\u73af\u4e2d\uff0c\u534f\u7a0bcoro1\u5728\u6267\u884c\u7b2c\u4e00\u53e5\u540e\u6302\u8d77\u81ea\u8eab\u5207\u5230asyncio.sleep\uff0c\u800c\u534f\u7a0bcoro2\u4e00\u76f4\u7b49\u5f85future\u7684\u7ed3\u679c\uff0c\u8ba9\u51fa\u4e8b\u4ef6\u5faa\u73af\uff0c\u8ba1\u65f6\u5668\u7ed3\u675f\u540ecoro1\u6267\u884c\u4e86\u7b2c\u4e8c\u53e5\u8bbe\u7f6e\u4e86future\u7684\u503c\uff0c\u88ab\u6302\u8d77\u7684coro2\u6062\u590d\u6267\u884c\uff0c\u6253\u5370\u51fafuture\u7684\u7ed3\u679c’data’\u3002<\/p>\n
future\u53ef\u4ee5\u88abawait\u8bc1\u660e\u4e86future\u5bf9\u8c61\u662f\u4e00\u4e2aAwaitable\uff0c\u8fdb\u5165Future\u7c7b\u7684\u6e90\u7801\u53ef\u4ee5\u770b\u5230\u6709\u4e00\u6bb5\u4ee3\u7801\u663e\u793a\u4e86future\u5b9e\u73b0\u4e86__await__\u534f\u8bae\uff1a<\/p>\n
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class<\/span> Future<\/span>:<\/span>\r\n    ...<\/span>\r\n    def<\/span> __iter__<\/span>(<\/span>self<\/span>):<\/span>\r\n        if<\/span> not<\/span> self<\/span>.<\/span>done<\/span>():<\/span>\r\n            self<\/span>.<\/span>_asyncio_future_blocking<\/span> =<\/span> True<\/span>\r\n            yield<\/span> self<\/span>  # This tells Task to wait for completion.<\/span>\r\n        assert<\/span> self<\/span>.<\/span>done<\/span>(),<\/span> \"yield from wasn't used with future\"<\/span>\r\n        return<\/span> self<\/span>.<\/span>result<\/span>()<\/span>  # May raise too.<\/span>\r\n\r\n    if<\/span> compat<\/span>.<\/span>PY35<\/span>:<\/span>\r\n        __await__<\/span> =<\/span> __iter__<\/span> # make compatible with 'await' expression<\/span><\/code><\/pre>\n<\/div>\n
\u5f53\u6267\u884cawait future<\/strong>\u8fd9\u884c\u4ee3\u7801\u65f6\uff0cfuture\u4e2d\u7684\u8fd9\u6bb5\u4ee3\u7801\u5c31\u4f1a\u88ab\u6267\u884c\uff0c\u9996\u5148future\u68c0\u67e5\u5b83\u81ea\u8eab\u662f\u5426\u5df2\u7ecf\u5b8c\u6210\uff0c\u5982\u679c\u6ca1\u6709\u5b8c\u6210\uff0c\u6302\u8d77\u81ea\u8eab\uff0c\u544a\u77e5\u5f53\u524d\u7684Task\uff08\u4efb\u52a1\uff09\u7b49\u5f85future\u5b8c\u6210\u3002<\/p>\n
\u5f53future\u6267\u884cset_result\u65b9\u6cd5\u65f6\uff0c\u4f1a\u89e6\u53d1\u4ee5\u4e0b\u7684\u4ee3\u7801\uff0c\u8bbe\u7f6e\u7ed3\u679c\uff0c\u6807\u8bb0future\u5df2\u7ecf\u5b8c\u6210\uff1a<\/p>\n
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def<\/span> set_result<\/span>(<\/span>self<\/span>,<\/span> result<\/span>):<\/span>\r\n    ...<\/span>\r\n    if<\/span> self<\/span>.<\/span>_state<\/span> !=<\/span> _PENDING<\/span>:<\/span>\r\n        raise<\/span> InvalidStateError<\/span>(<\/span>'{}: {!r}'<\/span>.<\/span>format<\/span>(<\/span>self<\/span>.<\/span>_state<\/span>,<\/span> self<\/span>))<\/span>\r\n    self<\/span>.<\/span>_result<\/span> =<\/span> result<\/span>\r\n    self<\/span>.<\/span>_state<\/span> =<\/span> _FINISHED<\/span>\r\n    self<\/span>.<\/span>_schedule_callbacks<\/span>()<\/span><\/code><\/pre>\n<\/div>\n
\u6700\u540efuture\u4f1a\u8c03\u5ea6\u81ea\u8eab\u7684\u56de\u8c03\u51fd\u6570\uff0c\u89e6\u53d1Task._step()\u544a\u77e5Task\u9a71\u52a8future\u4ece\u4e4b\u524d\u6302\u8d77\u7684\u70b9\u6062\u590d\u6267\u884c\uff0c\u4e0d\u96be\u770b\u51fa\uff0cfuture\u4f1a\u6267\u884c\u4e0b\u9762\u7684\u4ee3\u7801\uff1a<\/p>\n
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class<\/span> Future<\/span>:<\/span>\r\n    ...<\/span>\r\n    def<\/span> __iter__<\/span>(<\/span>self<\/span>):<\/span>\r\n        ...<\/span>\r\n        assert<\/span> self<\/span>.<\/span>done<\/span>(),<\/span> \"yield from wasn't used with future\"<\/span>\r\n        return<\/span> self<\/span>.<\/span>result<\/span>()<\/span>  # May raise too.<\/span><\/code><\/pre>\n<\/div>\n
\u6700\u7ec8\u8fd4\u56de\u7ed3\u679c\u7ed9\u8c03\u7528\u65b9\u3002<\/p>\n
\u524d\u9762\u8bb2\u4e86\u90a3\u4e48\u591a\u5173\u4e8easyncio\u7684\u4f8b\u5b50\uff0c\u90a3\u4e48\u9664\u4e86asyncio\uff0c\u5c31\u6ca1\u6709\u5176\u4ed6\u534f\u7a0b\u5e93\u4e86\u5417\uff1fasyncio\u4f5c\u4e3apython\u7684\u6807\u51c6\u5e93\uff0c\u81ea\u7136\u53d7\u5230\u5f88\u591a\u9752\u7750\uff0c\u4f46\u5b83\u6709\u65f6\u5019\u8fd8\u662f\u663e\u5f97\u592a\u91cd\u91cf\u4e86\uff0c\u5c24\u5176\u662f\u63d0\u4f9b\u4e86\u8bb8\u591a\u590d\u6742\u7684\u8f6e\u5b50\u548c\u534f\u8bae\uff0c\u4e0d\u4fbf\u4e8e\u4f7f\u7528\u3002<\/p>\n
\u4f60\u53ef\u4ee5\u7406\u89e3\u4e3a\uff0casyncio\u662f\u4f7f\u7528async\/await\u8bed\u6cd5\u5f00\u53d1\u7684\u534f\u7a0b\u5e93\uff0c\u800c\u4e0d\u662f\u6709asyncio\u624d\u80fd\u7528async\/await\uff0c\u9664\u4e86asyncio\u4e4b\u5916\uff0ccurio\u548ctrio\u662f\u66f4\u52a0\u8f7b\u91cf\u7ea7\u7684\u66ff\u4ee3\u7269\uff0c\u800c\u4e14\u4e5f\u66f4\u5bb9\u6613\u4f7f\u7528\u3002<\/p>\n
curio\u7684\u4f5c\u8005\u662fDavid Beazley\uff0c\u4e0b\u9762\u662f\u4f7f\u7528curio\u521b\u5efatcp server\u7684\u4f8b\u5b50\uff0c\u636e\u8bf4\u8fd9\u662fdabeaz\u7406\u60f3\u4e2d\u7684\u4e00\u4e2a\u5f02\u6b65\u670d\u52a1\u5668\u7684\u6837\u5b50\uff1a<\/p>\n
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from<\/span> curio<\/span> import<\/span> run<\/span>,<\/span> spawn<\/span>\r\nfrom<\/span> curio.socket<\/span> import<\/span> *<\/span>\r\n\r\nasync<\/span> def<\/span> echo_server<\/span>(<\/span>address<\/span>):<\/span>\r\n    sock<\/span> =<\/span> socket<\/span>(<\/span>AF_INET<\/span>,<\/span> SOCK_STREAM<\/span>)<\/span>\r\n    sock<\/span>.<\/span>setsockopt<\/span>(<\/span>SOL_SOCKET<\/span>,<\/span> SO_REUSEADDR<\/span>,<\/span> 1<\/span>)<\/span>\r\n    sock<\/span>.<\/span>bind<\/span>(<\/span>address<\/span>)<\/span>\r\n    sock<\/span>.<\/span>listen<\/span>(<\/span>5<\/span>)<\/span>\r\n    print<\/span>(<\/span>'Server listening at'<\/span>,<\/span> address<\/span>)<\/span>\r\n    async<\/span> with<\/span> sock<\/span>:<\/span>\r\n        while<\/span> True<\/span>:<\/span>\r\n            client<\/span>,<\/span> addr<\/span> =<\/span> await<\/span> sock<\/span>.<\/span>accept<\/span>()<\/span>\r\n            await<\/span> spawn<\/span>(<\/span>echo_client<\/span>,<\/span> client<\/span>,<\/span> addr<\/span>)<\/span>\r\n\r\nasync<\/span> def<\/span> echo_client<\/span>(<\/span>client<\/span>,<\/span> addr<\/span>):<\/span>\r\n    print<\/span>(<\/span>'Connection from'<\/span>,<\/span> addr<\/span>)<\/span>\r\n    async<\/span> with<\/span> client<\/span>:<\/span>\r\n         while<\/span> True<\/span>:<\/span>\r\n             data<\/span> =<\/span> await<\/span> client<\/span>.<\/span>recv<\/span>(<\/span>100000<\/span>)<\/span>\r\n             if<\/span> not<\/span> data<\/span>:<\/span>\r\n                 break<\/span>\r\n             await<\/span> client<\/span>.<\/span>sendall<\/span>(<\/span>data<\/span>)<\/span>\r\n    print<\/span>(<\/span>'Connection closed'<\/span>)<\/span>\r\n\r\nif<\/span> __name__<\/span> ==<\/span> '__main__'<\/span>:<\/span>\r\n    run<\/span>(<\/span>echo_server<\/span>,<\/span> (<\/span>''<\/span>,<\/span>25000<\/span>))<\/span><\/code><\/pre>\n<\/div>\n
\u65e0\u8bba\u662fasyncio\u8fd8\u662fcurio\uff0c\u6216\u8005\u662f\u5176\u4ed6\u5f02\u6b65\u534f\u7a0b\u5e93\uff0c\u5728\u80cc\u540e\u5f80\u5f80\u90fd\u4f1a\u501f\u52a9\u4e8eIO\u7684\u4e8b\u4ef6\u5faa\u73af\u6765\u5b9e\u73b0\u5f02\u6b65\uff0c\u4e0b\u9762\u7528\u51e0\u5341\u884c\u4ee3\u7801\u6765\u5c55\u793a\u4e00\u4e2a\u7b80\u964b\u7684\u57fa\u4e8e\u4e8b\u4ef6\u9a71\u52a8\u7684echo\u670d\u52a1\u5668\uff1a<\/p>\n
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from<\/span> socket<\/span> import<\/span> socket<\/span>,<\/span> AF_INET<\/span>,<\/span> SOCK_STREAM<\/span>,<\/span> SOL_SOCKET<\/span>,<\/span> SO_REUSEADDR<\/span>\r\nfrom<\/span> selectors<\/span> import<\/span> DefaultSelector<\/span>,<\/span> EVENT_READ<\/span>\r\n\r\nselector<\/span> =<\/span> DefaultSelector<\/span>()<\/span>\r\npool<\/span> =<\/span> {}<\/span>\r\n\r\ndef<\/span> request<\/span>(<\/span>client_socket<\/span>,<\/span> addr<\/span>):<\/span>\r\n    client_socket<\/span>,<\/span> addr<\/span> =<\/span> client_socket<\/span>,<\/span> addr<\/span>\r\n    def<\/span> handle_request<\/span>(<\/span>key<\/span>,<\/span> mask<\/span>):<\/span>\r\n        data<\/span> =<\/span> client_socket<\/span>.<\/span>recv<\/span>(<\/span>100000<\/span>)<\/span>\r\n        if<\/span> not<\/span> data<\/span>:<\/span>\r\n            client_socket<\/span>.<\/span>close<\/span>()<\/span>\r\n            selector<\/span>.<\/span>unregister<\/span>(<\/span>client_socket<\/span>)<\/span>\r\n            del<\/span> pool<\/span>[<\/span>addr<\/span>]<\/span>\r\n        else<\/span>:<\/span>\r\n            client_socket<\/span>.<\/span>sendall<\/span>(<\/span>data<\/span>)<\/span>\r\n    return<\/span> handle_request<\/span>\r\n\r\ndef<\/span> recv_client<\/span>(<\/span>key<\/span>,<\/span> mask<\/span>):<\/span>\r\n    sock<\/span> =<\/span> key<\/span>.<\/span>fileobj<\/span>\r\n    client_socket<\/span>,<\/span> addr<\/span> =<\/span> sock<\/span>.<\/span>accept<\/span>()<\/span>\r\n    req<\/span> =<\/span> request<\/span>(<\/span>client_socket<\/span>,<\/span> addr<\/span>)<\/span>\r\n    pool<\/span>[<\/span>addr<\/span>]<\/span> =<\/span> req<\/span>\r\n    selector<\/span>.<\/span>register<\/span>(<\/span>client_socket<\/span>,<\/span> EVENT_READ<\/span>,<\/span> req<\/span>)<\/span>\r\n\r\ndef<\/span> echo_server<\/span>(<\/span>address<\/span>):<\/span>\r\n    sock<\/span> =<\/span> socket<\/span>(<\/span>AF_INET<\/span>,<\/span> SOCK_STREAM<\/span>)<\/span>\r\n    sock<\/span>.<\/span>setsockopt<\/span>(<\/span>SOL_SOCKET<\/span>,<\/span> SO_REUSEADDR<\/span>,<\/span> 1<\/span>)<\/span>\r\n    sock<\/span>.<\/span>bind<\/span>(<\/span>address<\/span>)<\/span>\r\n    sock<\/span>.<\/span>listen<\/span>(<\/span>5<\/span>)<\/span>\r\n    selector<\/span>.<\/span>register<\/span>(<\/span>sock<\/span>,<\/span> EVENT_READ<\/span>,<\/span> recv_client<\/span>)<\/span>\r\n    try<\/span>:<\/span>\r\n        while<\/span> True<\/span>:<\/span>\r\n            events<\/span> =<\/span> selector<\/span>.<\/span>select<\/span>()<\/span>\r\n            for<\/span> key<\/span>,<\/span> mask<\/span> in<\/span> events<\/span>:<\/span>\r\n                callback<\/span> =<\/span> key<\/span>.<\/span>data<\/span>\r\n                callback<\/span>(<\/span>key<\/span>,<\/span> mask<\/span>)<\/span>\r\n    except<\/span> KeyboardInterrupt<\/span>:<\/span>\r\n        sock<\/span>.<\/span>close<\/span>()<\/span>\r\n\r\nif<\/span> __name__<\/span> ==<\/span> '__main__'<\/span>:<\/span>\r\n    echo_server<\/span>((<\/span>''<\/span>,<\/span>25000<\/span>))<\/span><\/code><\/pre>\n<\/div>\n
\u9a8c\u8bc1\u4e00\u4e0b\uff1a<\/p>\n
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# terminal 1<\/span>\r\n$ nc localhost 25000<\/span>\r\nhello world\r\nhello world\r\n\r\n# terminal 2<\/span>\r\n$ nc localhost 25000<\/span>\r\nhello world\r\nhello world<\/code><\/pre>\n<\/div>\n
\u73b0\u5728\u77e5\u9053\uff0c\u5b8c\u6210\u5f02\u6b65\u7684\u4ee3\u7801\u4e0d\u4e00\u5b9a\u8981\u7528async\/await\uff0c\u4f7f\u7528\u4e86async\/await\u7684\u4ee3\u7801\u4e5f\u4e0d\u4e00\u5b9a\u80fd\u505a\u5230\u5f02\u6b65\uff0casync\/await\u662f\u534f\u7a0b\u7684\u8bed\u6cd5\u7cd6\uff0c\u4f7f\u534f\u7a0b\u4e4b\u95f4\u7684\u8c03\u7528\u53d8\u5f97\u66f4\u52a0\u6e05\u6670\uff0c\u4f7f\u7528async\u4fee\u9970\u7684\u51fd\u6570\u8c03\u7528\u65f6\u4f1a\u8fd4\u56de\u4e00\u4e2a\u534f\u7a0b\u5bf9\u8c61\uff0cawait\u53ea\u80fd\u653e\u5728async\u4fee\u9970\u7684\u51fd\u6570\u91cc\u9762\u4f7f\u7528\uff0cawait\u540e\u9762\u5fc5\u987b\u8981\u8ddf\u7740\u4e00\u4e2a\u534f\u7a0b\u5bf9\u8c61\u6216Awaitable\uff0cawait\u7684\u76ee\u7684\u662f\u7b49\u5f85\u534f\u7a0b\u63a7\u5236\u6d41\u7684\u8fd4\u56de\uff0c\u800c\u5b9e\u73b0\u6682\u505c\u5e76\u6302\u8d77\u51fd\u6570\u7684\u64cd\u4f5c\u662fyield\u3002<\/p>\n
\u4e2a\u4eba\u8ba4\u4e3a\uff0casync\/await\u4ee5\u53ca\u534f\u7a0b\u662fPython\u672a\u6765\u5b9e\u73b0\u5f02\u6b65\u7f16\u7a0b\u7684\u8d8b\u52bf\uff0c\u6211\u4eec\u5c06\u4f1a\u5728\u66f4\u591a\u7684\u5730\u65b9\u770b\u5230\u4ed6\u4eec\u7684\u8eab\u5f71\uff0c\u4f8b\u5982\u534f\u7a0b\u5e93\u7684curio\u548ctrio\uff0cweb\u6846\u67b6\u7684sanic\uff0c\u6570\u636e\u5e93\u9a71\u52a8\u7684asyncpg\u7b49\u7b49…\u5728Python 3\u4e3b\u5bfc\u7684\u4eca\u5929\uff0c\u4f5c\u4e3a\u5f00\u53d1\u8005\uff0c\u5e94\u8be5\u53ca\u65f6\u62e5\u62b1\u548c\u9002\u5e94\u65b0\u7684\u53d8\u5316\uff0c\u800c\u57fa\u4e8easync\/await\u7684\u534f\u7a0b\u51ed\u501f\u826f\u597d\u7684\u53ef\u8bfb\u6027\u548c\u6613\u7528\u6027\u65e5\u6e10\u767b\u4e0a\u821e\u53f0\uff0c\u770b\u5230\u8fd9\u91cc\uff0c\u4f60\u8fd8\u4e0d\u8d76\u7d27\u4e0a\u8f66\uff1f<\/p>\n
\u53c2\u8003\uff1a<\/p>\n
PEP 492<\/a>PEP 525<\/a><\/div>\n<\/div>\n
\u7f16\u8f91\u4e8e 2017-06-05<\/div>\n","protected":false},"excerpt":{"rendered":"
\u539f\u6587\u5730\u5740 \u672c\u6587\u5c06\u4f1a\u8bb2\u8ff0Python 3.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"colormag_page_container_layout":"default_layout","colormag_page_sidebar_layout":"default_layout","footnotes":""},"categories":[],"tags":[118],"class_list":["post-4979","post","type-post","status-publish","format-standard","hentry","tag-02-"],"_links":{"self":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/posts\/4979","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/comments?post=4979"}],"version-history":[{"count":0,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/posts\/4979\/revisions"}],"wp:attachment":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/media?parent=4979"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/categories?post=4979"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/tags?post=4979"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}