{"id":98,"date":"2026-08-06T00:29:31","date_gmt":"2026-08-05T16:29:31","guid":{"rendered":"https:\/\/ltrainyard.icu\/?p=98"},"modified":"2026-08-06T00:44:34","modified_gmt":"2026-08-05T16:44:34","slug":"day-16-%e7%bb%a7%e6%89%bf%e4%b8%8e%e5%a4%9a%e6%80%81%ef%bc%9amro%e3%80%81super%e3%80%81%e6%96%b9%e6%b3%95%e9%87%8d%e5%86%99%e4%b8%8e%e9%b8%ad%e5%ad%90%e7%b1%bb%e5%9e%8b","status":"publish","type":"post","link":"https:\/\/ltrainyard.icu\/index.php\/2026\/08\/06\/day-16-%e7%bb%a7%e6%89%bf%e4%b8%8e%e5%a4%9a%e6%80%81%ef%bc%9amro%e3%80%81super%e3%80%81%e6%96%b9%e6%b3%95%e9%87%8d%e5%86%99%e4%b8%8e%e9%b8%ad%e5%ad%90%e7%b1%bb%e5%9e%8b\/","title":{"rendered":"| Day 16 | \u7ee7\u627f\u4e0e\u591a\u6001\uff1aMRO\u3001super\u3001\u65b9\u6cd5\u91cd\u5199\u4e0e\u9e2d\u5b50\u7c7b\u578b |"},"content":{"rendered":"\n<h3 class=\"wp-block-heading\">1 \u7ee7\u627f\u7684\u672c\u8d28 \u2014\u2014 \u5b50\u7c7b\u4e3a\u4ec0\u4e48\u300c\u81ea\u52a8\u62e5\u6709\u300d\u7236\u7c7b\u7684\u65b9\u6cd5<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u662f\u4ec0\u4e48\uff1f\u4e3a\u4ec0\u4e48\u5b66\uff1f<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u7ee7\u627f<\/strong>\uff08inheritance\uff09\u8ba9\u4e00\u4e2a\u7c7b\uff08\u5b50\u7c7b\uff09<strong>\u81ea\u52a8\u83b7\u5f97<\/strong>\u53e6\u4e00\u4e2a\u7c7b\uff08\u7236\u7c7b\uff09\u7684\u5c5e\u6027\u548c\u65b9\u6cd5\uff0c\u4e0d\u7528\u91cd\u65b0\u5199\u4e00\u904d\u3002\u771f\u5b9e\u9879\u76ee\u91cc\uff0c\u591a\u4e2a\u7c7b\u6709\u516c\u5171\u903b\u8f91\u662f\u5e38\u6001\uff1a\u72d7\u3001\u732b\u3001\u9e1f\u90fd\u6709\u540d\u5b57\u3001\u90fd\u8981\u5403\u4e1c\u897f\uff0c\u628a\u516c\u5171\u90e8\u5206\u5199\u8fdb <code>Animal<\/code>\uff0c\u4e09\u4e2a\u5b50\u7c7b\u5404\u5199\u5404\u7684\u7279\u957f\u2014\u2014\u4ee3\u7801\u91cf\u9aa4\u51cf\uff0c\u6539\u516c\u5171\u903b\u8f91\u4e5f\u53ea\u6539\u4e00\u5904\u3002\u7ee7\u627f\u89e3\u51b3\u300c\u590d\u7528\u300d\u2014\u2014\u516c\u5171\u4ee3\u7801\u53ea\u5199\u4e00\u904d\uff0c\u5b50\u7c7b\u81ea\u52a8\u62e5\u6709\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u5e95\u5c42\u539f\u7406<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u7c7b\u4e0e\u7c7b\u4e4b\u95f4\u5b58\u5728\u4e00\u6761<strong>\u67e5\u627e\u94fe<\/strong>\uff0c\u53eb MRO\uff08\u65b9\u6cd5\u89e3\u6790\u987a\u5e8f\uff0cMethod Resolution Order\uff09\u3002\u8bbf\u95ee <code>dog.eat()<\/code> \u65f6\uff0cPython \u6cbf\u7740 MRO \u4f9d\u6b21\u67e5\u627e\uff1a\u5148\u67e5 <code>Dog<\/code> \u7c7b\uff0c\u627e\u4e0d\u5230\u5c31\u67e5 <code>Animal<\/code>\uff0c\u518d\u627e\u4e0d\u5230\u67e5 <code>object<\/code>\uff08\u6240\u6709\u7c7b\u7684\u6839\uff09\u3002\u5b50\u7c7b\u91cc\u6ca1\u5b9a\u4e49 <code>eat<\/code>\uff0c\u4f46\u7236\u7c7b\u91cc\u6709\uff0c\u6240\u4ee5\u80fd\u7528\u2014\u2014\u300c\u81ea\u52a8\u62e5\u6709\u300d\u7684\u771f\u76f8\u662f<strong>\u67e5\u4e0d\u5230\u81ea\u5df1\u5c31\u53bb\u7236\u7c7b\u627e<\/strong>\uff0c\u65b9\u6cd5\u4ee3\u7801\u5176\u5b9e\u53ea\u6709\u4e00\u4efd\uff0c\u5e76\u6ca1\u6709\u590d\u5236\u3002<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\">\u672f\u8bed\u5c0f\u8bcd\u5178\uff1a<strong>MRO<\/strong>\uff08\u65b9\u6cd5\u89e3\u6790\u987a\u5e8f\uff09\u5c31\u662f\u300c\u7c7b\u4e0e\u7c7b\u4e4b\u95f4\u7684\u67e5\u627e\u94fe\u300d\u2014\u2014\u50cf\u5bb6\u8c31\uff0c\u67e5\u65b9\u6cd5\u65f6\u6309\u8f88\u5206\u4e00\u4ee3\u4ee3\u5f80\u4e0a\u627e\u3002<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u751f\u6d3b\u7c7b\u6bd4<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u7ee7\u627f\u50cf<strong>\u7956\u4f20\u624b\u827a<\/strong>\uff1a\u7237\u7237\u4f1a\u505a\u6728\u5de5\uff08\u7236\u7c7b\uff09\uff0c\u7238\u7238\u6ca1\u5b66\u4e5f\u300c\u7ee7\u627f\u300d\u4e86\u8fd9\u4efd\u80fd\u529b\u2014\u2014\u4e0d\u662f\u91cd\u65b0\u53d1\u660e\uff0c\u800c\u662f\u300c\u8981\u6728\u5de5\u6d3b\u65f6\uff0c\u6309\u5bb6\u8c31\uff08MRO\uff09\u627e\u5230\u7237\u7237\u90a3\u4efd\u624b\u827a\u6765\u7528\u300d\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u6ce8\u610f\u4e8b\u9879\u603b\u7ed3<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">1 <strong>\u5b50\u7c7b\u6ca1\u5199 eat \u4e5f\u80fd\u8c03\u7528\uff1bMRO \u5c31\u662f\u90a3\u6761\u67e5\u627e\u94fe<\/strong>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>class Animal:\n    def eat(self):\n        print(\"\u6b63\u5728\u5403\u4e1c\u897f\")\n\nclass Dog(Animal):\n    pass          # \u5b50\u7c7b\u4e00\u4e2a\u5b57\u90fd\u4e0d\u5199\n\ndog = Dog()\ndog.eat()                          # \u80fd\u7528\uff01\nprint(\"eat\" in Dog.__dict__)       # Dog \u81ea\u5df1\u6ca1\u5b9a\u4e49 eat\nprint(\"eat\" in Animal.__dict__)    # \u5b9a\u4e49\u5728 Animal \u91cc\nprint(Dog.__mro__)                 # \u67e5\u627e\u94fe\uff1aDog \u2192 Animal \u2192 object\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd0\u884c\u7ed3\u679c\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\u6b63\u5728\u5403\u4e1c\u897f\nFalse\nTrue\n(&lt;class '__main__.Dog'&gt;, &lt;class '__main__.Animal'&gt;, &lt;class 'object'&gt;)\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><code>Dog(Animal)<\/code> \u62ec\u53f7\u91cc\u7684 <code>Animal<\/code> \u5c31\u662f\u7236\u7c7b\u3002<code>dog.eat()<\/code> \u80fd\u6267\u884c\uff0c\u662f\u56e0\u4e3a\u6cbf\u7740 MRO \u627e\u5230\u4e86 <code>Animal.eat<\/code>\uff1b<code>Dog.__mro__<\/code> \u6253\u5370\u7684\u5c31\u662f\u67e5\u627e\u94fe\uff1a\u5148 <code>Dog<\/code> \u81ea\u5df1\uff0c\u518d\u7236\u7c7b <code>Animal<\/code>\uff0c\u6700\u540e\u6240\u6709\u7c7b\u7684\u7956\u5148 <code>object<\/code>\u3002<strong>\u5b50\u7c7b\u5e76\u6ca1\u6709\u590d\u5236\u4ee3\u7801\uff0c\u53ea\u662f\u300c\u501f\u7528\u300d\u3002<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u6613\u9519\u70b9<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u9519\u8bef\u5199\u6cd5\uff1a\u7ee7\u627f\u5199\u53cd\uff1a<code>class Animal(Dog)<\/code> \u2192 \u95ee\u9898\uff1a\u8bed\u4e49\u98a0\u5012\uff0cDog \u8fd8\u6ca1\u5b9a\u4e49\u65f6\u76f4\u63a5\u62a5 <code>NameError<\/code> \u2192 \u6b63\u786e\u5199\u6cd5\uff1a\u7236\u7c7b\u5728\u524d\u5b9a\u4e49\uff0c\u5b50\u7c7b\u5199 <code>class Dog(Animal)<\/code>\u3002<\/li>\n\n\n\n<li>\u9519\u8bef\u5199\u6cd5\uff1a\u4ee5\u4e3a\u5b50\u7c7b\u4f1a\u300c\u590d\u5236\u300d\u7236\u7c7b\u65b9\u6cd5 \u2192 \u95ee\u9898\uff1a\u65b9\u6cd5\u53ea\u6709\u4e00\u4efd\uff0c\u5b50\u7c7b\u53ea\u662f\u6309 MRO \u501f\u7528 \u2192 \u6b63\u786e\u5199\u6cd5\uff1a\u7406\u89e3 MRO\uff1a\u5148\u67e5\u81ea\u5df1\uff0c\u518d\u6cbf\u94fe\u5411\u4e0a\u627e\u3002<\/li>\n\n\n\n<li>\u9519\u8bef\u5199\u6cd5\uff1a\u5b50\u7c7b\u4e0e\u7236\u7c7b\u65b9\u6cd5\u540c\u540d\u5374\u4e0d\u60f3\u8981\u7236\u7c7b\u884c\u4e3a \u2192 \u95ee\u9898\uff1a\u540c\u540d\u5373\u91cd\u5199\uff0c\u7236\u7c7b\u7248\u672c\u88ab\u5b8c\u5168\u8986\u76d6 \u2192 \u6b63\u786e\u5199\u6cd5\uff1a\u60f3\u4fdd\u7559\u90e8\u5206\u7236\u7c7b\u884c\u4e3a\uff0c\u7528 <code>super()<\/code> \u8c03\u7528\u7236\u7c7b\u7248\u672c\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u8bb0\u5fc6\u53e3\u8bc0<\/strong>\uff1a\u5b50\u7c7b\u7ee7\u627f\u7236\u7c7b\u4ea7\uff0c\u65b9\u6cd5\u4e0d\u590d\u5236\u53ea\u501f\u7528\uff1b\u67e5\u627e\u6cbf MRO\uff0c\u81ea\u5df1\u3001\u7236\u7c7b\u3001object\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">2 super() \u7684\u771f\u76f8 \u2014\u2014 \u5148\u8bf7\u7236\u7c7b\u300c\u5f00\u4e2a\u5934\u300d<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u662f\u4ec0\u4e48\uff1f\u4e3a\u4ec0\u4e48\u5b66\uff1f<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><code>super().__init__(...)<\/code> \u662f\u5728\u5b50\u7c7b\u7684\u65b9\u6cd5\u91cc<strong>\u8c03\u7528\u7236\u7c7b\u7684\u540c\u540d\u65b9\u6cd5<\/strong>\uff0c\u6700\u5e38\u89c1\u7684\u573a\u666f\uff1a\u5b50\u7c7b <code>__init__<\/code> \u5148\u8ba9\u7236\u7c7b\u521d\u59cb\u5316\u516c\u5171\u5c5e\u6027\uff08\u5982 <code>name<\/code>\uff09\uff0c\u518d\u521d\u59cb\u5316\u81ea\u5df1\u7279\u6709\u7684\u5c5e\u6027\uff08\u5982 <code>breed<\/code>\uff09\u3002\u4e0d\u5b66 super\uff0c\u5b50\u7c7b\u5c31\u5f97\u628a\u7236\u7c7b\u7684\u521d\u59cb\u5316\u4ee3\u7801\u91cd\u6284\u4e00\u904d\uff0c\u7236\u7c7b\u4e00\u6539\uff0c\u6240\u6709\u5b50\u7c7b\u8ddf\u7740\u6539\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u5e95\u5c42\u539f\u7406<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><code>super()<\/code> \u8fd4\u56de\u4e00\u4e2a\u7279\u6b8a\u7684\u4ee3\u7406\u5bf9\u8c61\uff0c\u5b83<strong>\u6cbf\u7740 MRO \u4ece\u300c\u5f53\u524d\u7c7b\u7684\u4e0b\u4e00\u4e2a\u7c7b\u300d\u5f00\u59cb\u67e5\u627e\u65b9\u6cd5<\/strong>\u3002\u6bd4\u5982 <code>Dog<\/code> \u7684 MRO \u662f <code>Dog \u2192 Animal \u2192 object<\/code>\uff0c\u5728 Dog \u91cc\u5199 <code>super().__init__(name)<\/code>\uff0c\u5c31\u662f\u300c\u4ece Animal \u5f00\u59cb\u627e <code>__init__<\/code>\u300d\u2014\u2014\u4e8e\u662f\u7236\u7c7b\u7684\u521d\u59cb\u5316\u903b\u8f91\u88ab\u6267\u884c\u3002\u5b83\u548c\u300c\u663e\u5f0f\u5199 <code>Animal.__init__(self, name)<\/code>\u300d\u6548\u679c\u7c7b\u4f3c\uff0c\u4f46\u7528 super \u66f4\u7a33\uff1a\u7236\u7c7b\u6539\u540d\u3001\u591a\u7ee7\u627f\u65f6\u90fd\u4e0d\u4f1a\u5199\u9519\u5bf9\u8c61\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u751f\u6d3b\u7c7b\u6bd4<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><code>super()<\/code> \u50cf<strong>\u65b0\u5458\u5de5\u5165\u804c\u57f9\u8bad<\/strong>\uff1a\u516c\u53f8\uff08\u7236\u7c7b\uff09\u6709\u4e00\u5957\u516c\u5171\u57f9\u8bad\uff08\u521d\u59cb\u5316 name\uff09\uff0c\u90e8\u95e8\uff08\u5b50\u7c7b\uff09\u5148\u5b89\u6392\u4f60\u53c2\u52a0\u516c\u53f8\u57f9\u8bad\uff08<code>super().__init__<\/code>\uff09\uff0c\u518d\u7ed9\u4f60\u90e8\u95e8\u4e13\u5c5e\u57f9\u8bad\uff08\u8bbe\u7f6e breed\uff09\u2014\u2014\u987a\u5e8f\u4e0d\u80fd\u53cd\uff0c\u5148\u6709\u516c\u53f8\u8eab\u4efd\uff0c\u624d\u6709\u90e8\u95e8\u8eab\u4efd\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u6ce8\u610f\u4e8b\u9879\u603b\u7ed3<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">1 <strong>\u4e0d\u8c03 super \u7684\u540e\u679c vs \u8c03 super \u7684\u6b63\u786e\u5199\u6cd5<\/strong>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>class Animal:\n    def __init__(self, name):\n        self.name = name\n\nclass DogNoSuper(Animal):\n    def __init__(self, name, breed):\n        self.breed = breed     # \u53ea\u521d\u59cb\u5316\u4e86\u81ea\u5df1\u7684\u5c5e\u6027\n\nclass Dog(Animal):\n    def __init__(self, name, breed):\n        super().__init__(name)    # \u5148\u8ba9\u7236\u7c7b\u521d\u59cb\u5316 name\n        self.breed = breed        # \u518d\u521d\u59cb\u5316\u81ea\u5df1\u7684 breed\n\nbad = DogNoSuper(\"\u65fa\u8d22\", \"\u91d1\u6bdb\")\nprint(bad.breed)\n# print(bad.name)     # \u53d6\u6d88\u6ce8\u91ca\u4f1a\u62a5 AttributeError\uff1a\u6ca1\u6709 name \u5c5e\u6027\ngood = Dog(\"\u65fa\u8d22\", \"\u91d1\u6bdb\")\nprint(good.name, good.breed)\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd0\u884c\u7ed3\u679c\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\u91d1\u6bdb\n\u65fa\u8d22 \u91d1\u6bdb\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u5bf9\u6bd4\u4e24\u4e2a\u5b50\u7c7b\u2014\u2014<code>DogNoSuper<\/code> \u91cd\u5199\u4e86 <code>__init__<\/code> \u5374\u6ca1\u8c03 super\uff0c\u7236\u7c7b\u7684 <code>__init__<\/code> <strong>\u4e0d\u4f1a\u81ea\u52a8\u6267\u884c<\/strong>\uff0c<code>name<\/code> \u6839\u672c\u6ca1\u88ab\u521d\u59cb\u5316\uff0c\u4e00\u8bbf\u95ee\u5c31\u70b8\uff1b<code>Dog<\/code> \u7b2c\u4e00\u884c\u5199 <code>super().__init__(name)<\/code>\uff08<strong>\u4e0d\u9700\u8981\u4f20 self<\/strong>\uff09\uff0c\u5148\u521d\u59cb\u5316 name \u518d\u8bbe\u7f6e breed\u2014\u2014\u987a\u5e8f\u8bb2\u7a76<strong>\u5148\u7236\u540e\u5b50<\/strong>\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u6613\u9519\u70b9<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u9519\u8bef\u5199\u6cd5\uff1a\u5b50\u7c7b\u91cd\u5199 <code>__init__<\/code> \u5374\u4e0d\u8c03 super \u2192 \u95ee\u9898\uff1a\u7236\u7c7b\u5c5e\u6027\u6ca1\u521d\u59cb\u5316\uff0c\u8bbf\u95ee\u62a5 <code>AttributeError<\/code> \u2192 \u6b63\u786e\u5199\u6cd5\uff1a\u5b50\u7c7b <code>__init__<\/code> \u7b2c\u4e00\u884c\u5199 <code>super().__init__(...)<\/code>\u3002<\/li>\n\n\n\n<li>\u9519\u8bef\u5199\u6cd5\uff1asuper \u8c03\u7528\u65f6\u624b\u52a8\u4f20 self\uff1a<code>super().__init__(self, name)<\/code> \u2192 \u95ee\u9898\uff1a\u62a5\u53c2\u6570\u4e2a\u6570\u9519\u8bef\uff08self \u4f1a\u88ab\u91cd\u590d\u4f20\u5165\uff09 \u2192 \u6b63\u786e\u5199\u6cd5\uff1a<code>super().__init__(name)<\/code>\uff0c\u4e0d\u8981\u5199 self\u3002<\/li>\n\n\n\n<li>\u9519\u8bef\u5199\u6cd5\uff1a\u5fd8\u4e86 super \u7684\u8fd4\u56de\u8981\u7528\uff08<code>x = super()<\/code>\uff09 \u2192 \u95ee\u9898\uff1a\u4e0d\u62a5\u9519\u4f46 super \u5fc5\u987b\u300c\u5f53\u573a\u70b9\u65b9\u6cd5\u300d\u7528\u6389 \u2192 \u6b63\u786e\u5199\u6cd5\uff1a\u76f4\u63a5\u94fe\u5f0f\u7528\uff1a<code>super().\u65b9\u6cd5\u540d(...)<\/code>\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u8bb0\u5fc6\u53e3\u8bc0<\/strong>\uff1a\u91cd\u5199\u4e4b\u540e\u7236\u7c7b\u505c\uff0csuper \u5e2e\u4f60\u5f00\u4e2a\u5934\uff1b\u5148\u7236\u540e\u5b50\u8bb2\u987a\u5e8f\uff0c\u8c03\u7236\u65b9\u6cd5\u4e0d\u4f20 self\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">3 \u65b9\u6cd5\u91cd\u5199 \u2014\u2014 \u5b50\u7c7b\u6309\u81ea\u5df1\u7684\u65b9\u5f0f\u505a\u540c\u4e00\u4ef6\u4e8b<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u662f\u4ec0\u4e48\uff1f\u4e3a\u4ec0\u4e48\u5b66\uff1f<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u91cd\u5199<\/strong>\uff08override\uff09\u6307\u5b50\u7c7b\u5b9a\u4e49\u4e0e\u7236\u7c7b<strong>\u540c\u540d<\/strong>\u7684\u65b9\u6cd5\uff0c\u8986\u76d6\u7236\u7c7b\u7248\u672c\u3002\u52a8\u7269\u90fd\u4f1a\u300c\u53eb\u300d\uff0c\u4f46\u72d7\u6c6a\u6c6a\u3001\u732b\u55b5\u55b5\u2014\u2014\u884c\u4e3a\u6309\u5b50\u7c7b\u5b9a\u5236\u3002\u91cd\u5199\u8ba9\u300c\u540c\u4e00\u4e2a\u6982\u5ff5\uff08speak\uff09\u6709\u7edf\u4e00\u7684\u540d\u5b57\uff0c\u5177\u4f53\u505a\u6cd5\u5404\u4e0d\u76f8\u540c\u300d\uff0c\u8fd9\u662f\u591a\u6001\uff08\u77e5\u8bc6\u70b9 4\uff09\u7684\u57fa\u77f3\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u5e95\u5c42\u539f\u7406<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u91cd\u5199\u7684\u539f\u7406\u5c31\u662f MRO \u7684\u300c\u5c31\u8fd1\u539f\u5219\u300d\uff1a\u8c03\u7528 <code>dog.speak()<\/code> \u65f6\u6cbf MRO \u67e5\u627e\uff0c<code>Dog<\/code> \u81ea\u5df1\u5b9a\u4e49\u4e86 <code>speak<\/code>\uff0c<strong>\u7b2c\u4e00\u4e2a\u5c31\u547d\u4e2d<\/strong>\uff0c\u7236\u7c7b\u7248\u672c\u6839\u672c\u4e0d\u4f1a\u88ab\u770b\u5230\u3002\u6240\u4ee5\u300c\u91cd\u5199\u300d\u4e0d\u662f\u5220\u9664\u7236\u7c7b\u65b9\u6cd5\uff0c\u800c\u662f<strong>\u5728\u67e5\u627e\u94fe\u4e0a\u7528\u81ea\u5df1\u7684\u7248\u672c\u300c\u6321\u4f4f\u300d\u7236\u7c7b\u7248\u672c<\/strong>\u3002\u60f3\u8981\u7236\u7c7b\u7248\u672c\uff1f<code>super().speak()<\/code> \u7ed5\u8fc7\u53bb\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u751f\u6d3b\u7c7b\u6bd4<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u91cd\u5199\u50cf<strong>\u540c\u6837\u7684\u83dc\u5355\uff0c\u4e0d\u540c\u53a8\u5e08<\/strong>\uff1a\u83dc\u5355\u4e0a\u5199\u7740\u300c\u62db\u724c\u83dc\u300d\uff08\u65b9\u6cd5\u540d speak\uff09\uff0c\u5ddd\u83dc\u5e08\u5085\u505a\u51fa\u6765\u662f\u8fa3\u7684\uff08\u6c6a\u6c6a\uff09\uff0c\u7ca4\u83dc\u5e08\u5085\u505a\u51fa\u6765\u662f\u6e05\u6de1\u7684\uff08\u55b5\u55b5\uff09\u2014\u2014\u987e\u5ba2\u53ea\u70b9\u300c\u62db\u724c\u83dc\u300d\uff0c\u5177\u4f53\u8c01\u505a\u3001\u600e\u4e48\u505a\uff0c\u7531\u540e\u53a8\uff08\u8fd0\u884c\u65f6\uff09\u51b3\u5b9a\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u6ce8\u610f\u4e8b\u9879\u603b\u7ed3<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">1 <strong>\u540c\u540d\u65b9\u6cd5\uff0c\u5404\u5b50\u7c7b\u5404\u7248\u672c<\/strong>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>class Animal:\n    def speak(self):\n        return \"\u52a8\u7269\u53eb\u4e86\u4e00\u58f0\"\n\nclass Dog(Animal):\n    def speak(self):\n        return \"\u6c6a\u6c6a\uff01\"\n\nclass Cat(Animal):\n    def speak(self):\n        return \"\u55b5\u55b5\uff5e\"\n\nfor obj in (Animal(), Dog(), Cat()):\n    print(obj.speak())\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd0\u884c\u7ed3\u679c\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\u52a8\u7269\u53eb\u4e86\u4e00\u58f0\n\u6c6a\u6c6a\uff01\n\u55b5\u55b5\uff5e\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e09\u4e2a\u7c7b\u90fd\u6709 <code>speak<\/code>\uff0c\u8c03\u7528\u65f6\u6309\u5bf9\u8c61\u81ea\u5df1\u7684\u7c7b\u627e\u2014\u2014<strong>\u8c01\u7684\u5bf9\u8c61\uff0c\u7528\u8c01\u7684\u7248\u672c<\/strong>\u3002\u7236\u7c7b\u7684 <code>speak<\/code> \u8fd8\u5728\uff0c\u53ea\u662f\u88ab\u5b50\u7c7b\u300c\u6321\u300d\u4f4f\u4e86\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u6613\u9519\u70b9<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u9519\u8bef\u5199\u6cd5\uff1a\u91cd\u5199\u65f6\u65b9\u6cd5\u540d\u62fc\u9519\uff08<code>speek<\/code> \u800c\u4e0d\u662f <code>speak<\/code>\uff09 \u2192 \u95ee\u9898\uff1a\u4e0d\u62a5\u9519\uff01\u4f46\u8c03\u7528\u65f6\u8d70\u7684\u662f\u7236\u7c7b\u7248\u672c\uff0c\u884c\u4e3a\u300c\u4e0d\u5bf9\u300d \u2192 \u6b63\u786e\u5199\u6cd5\uff1a\u91cd\u5199\u5fc5\u987b\u4e0e\u7236\u7c7b\u65b9\u6cd5<strong>\u5b8c\u5168\u540c\u540d<\/strong>\uff0c\u5199\u5b8c\u68c0\u67e5\u3002<\/li>\n\n\n\n<li>\u9519\u8bef\u5199\u6cd5\uff1a\u91cd\u5199\u540e\u60f3\u4fdd\u7559\u7236\u7c7b\u884c\u4e3a\u5374\u5fd8\u4e86 super \u2192 \u95ee\u9898\uff1a\u7236\u7c7b\u884c\u4e3a\u5b8c\u5168\u4e22\u5931\uff0c\u7ed3\u679c\u4e0d\u5b8c\u6574 \u2192 \u6b63\u786e\u5199\u6cd5\uff1a\u9700\u8981\u7236\u7c7b\u884c\u4e3a\u65f6\uff1a<code>super().\u65b9\u6cd5\u540d(...)<\/code> \u518d\u8865\u5145\u3002<\/li>\n\n\n\n<li>\u9519\u8bef\u5199\u6cd5\uff1a\u91cd\u5199\u65b9\u6cd5\u53c2\u6570\u4e0e\u7236\u7c7b\u4e0d\u4e00\u81f4 \u2192 \u95ee\u9898\uff1a\u53ef\u80fd\u62a5 <code>TypeError<\/code>\uff08\u7236\u7c7b\u8c03\u7528\u65b9\u6309\u539f\u53c2\u6570\u8c03\u7528\uff09 \u2192 \u6b63\u786e\u5199\u6cd5\uff1a\u91cd\u5199\u65f6\u53c2\u6570\u5217\u8868\u4e0e\u7236\u7c7b\u4fdd\u6301\u4e00\u81f4\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u8bb0\u5fc6\u53e3\u8bc0<\/strong>\uff1a\u540c\u540d\u65b9\u6cd5\u6321\u7236\u7248\uff0c\u5c31\u8fd1\u547d\u4e2d\u4e0d\u5546\u91cf\uff1b\u8981\u7559\u7236\u7c7b\u4e00\u5c0f\u5757\uff0csuper \u8c03\u7528\u518d\u589e\u5f3a\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">4 \u591a\u6001\u7684\u672c\u8d28 \u2014\u2014 \u52a8\u6001\u5206\u6d3e\uff0c\u8fd0\u884c\u65f6\u624d\u300c\u70b9\u540d\u300d<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u662f\u4ec0\u4e48\uff1f\u4e3a\u4ec0\u4e48\u5b66\uff1f<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u591a\u6001<\/strong>\uff08polymorphism\uff09\u7684\u610f\u601d\u662f\uff1a<strong>\u540c\u4e00\u4e2a\u65b9\u6cd5\u540d\uff0c\u5bf9\u4e0d\u540c\u5bf9\u8c61\u8c03\u7528\uff0c\u6267\u884c\u5404\u81ea\u7248\u672c<\/strong>\u3002\u5199\u4ee3\u7801\u7684\u4eba\u4e0d\u9700\u8981\u77e5\u9053\u5bf9\u8c61\u5177\u4f53\u662f\u8c01\uff0c\u53ea\u8981\u5b83\u6709\u8fd9\u4e2a\u65b9\u6cd5\u5c31\u80fd\u8c03\u7528\u3002\u8fd9\u8ba9\u4f60\u80fd\u5199\u300c\u9762\u5bf9\u62bd\u8c61\u300d\u7684\u901a\u7528\u4ee3\u7801\u2014\u2014\u65b0\u52a0\u4e00\u4e2a\u7c7b\uff0c\u65e7\u4ee3\u7801\u4e00\u884c\u4e0d\u6539\u3002\u7ee7\u627f\u89e3\u51b3\u300c\u590d\u7528\u300d\uff0c\u591a\u6001\u89e3\u51b3\u300c\u7075\u6d3b\u300d\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u5e95\u5c42\u539f\u7406<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u591a\u6001\u7684\u5e95\u5c42\u673a\u5236\u53eb<strong>\u52a8\u6001\u5206\u6d3e<\/strong>\uff08dynamic dispatch\uff09\uff1a<code>obj.speak()<\/code> \u5728<strong>\u8fd0\u884c\u65f6<\/strong>\u624d\u6839\u636e <code>obj<\/code> \u7684\u5b9e\u9645\u7c7b\u578b\u67e5\u627e\u65b9\u6cd5\uff08\u6cbf MRO \u627e <code>speak<\/code>\uff09\uff0c\u800c\u4e0d\u662f\u5728\u5199\u4ee3\u7801\u65f6\u5b9a\u6b7b\u3002\u6240\u4ee5\u540c\u4e00\u4e2a\u51fd\u6570\u91cc\uff0c\u4f20\u5165\u7684\u6bcf\u4e2a\u5bf9\u8c61\u90fd\u4f1a\u5404\u81ea\u8c03\u7528\u81ea\u5df1\u7684\u7248\u672c\u2014\u2014\u300c\u5bf9\u8c61\u81ea\u5df1\u51b3\u5b9a\u600e\u4e48\u505a\u300d\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u751f\u6d3b\u7c7b\u6bd4<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u591a\u6001\u50cf<strong>\u5e7f\u64ad\u4f53\u64cd\u7684\u300c\u5404\u5c31\u5404\u4f4d\u300d<\/strong>\uff1a\u5e7f\u64ad\u558a\u4e00\u58f0\u300c\u96c6\u5408\uff01\u300d\uff08\u540c\u4e00\u4e2a\u8c03\u7528\uff09\uff0c\u64cd\u573a\u4e0a\u7684\u6bcf\u4e2a\u73ed\uff08\u5bf9\u8c61\uff09\u6309\u81ea\u5df1\u7684\u4f4d\u7f6e\u7ad9\u597d\uff08\u5404\u81ea\u7684\u884c\u4e3a\uff09\u2014\u2014\u5e7f\u64ad\u4e0d\u9700\u8981\u8ba4\u8bc6\u6bcf\u4e2a\u73ed\u7684\u6bcf\u4e2a\u4eba\uff0c\u53ea\u8981\u5927\u5bb6\u542c\u5f97\u61c2\u53e3\u4ee4\u5c31\u884c\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u6ce8\u610f\u4e8b\u9879\u603b\u7ed3<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">1 <strong>\u4e0d\u9700\u8981\u77e5\u9053\u5bf9\u8c61\u662f\u8c01\uff0c\u4f1a\u300c\u53eb\u300d\u5c31\u884c\uff1b\u5185\u7f6e\u51fd\u6570 len \u4e5f\u4e00\u6837<\/strong>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>class Dog:\n    def speak(self):\n        return \"\u6c6a\u6c6a\"\n\nclass Cat:\n    def speak(self):\n        return \"\u55b5\u55b5\"\n\nclass Duck:\n    def speak(self):\n        return \"\u560e\u560e\"\n\ndef chorus(animals):\n    for a in animals:\n        print(a.speak())\n\nchorus(&#91;Dog(), Cat(), Duck()])\n\nclass Team:\n    def __init__(self, members):\n        self.members = members\n\n    def __len__(self):\n        return len(self.members)\n\nprint(len(Team(&#91;\"\u5f20\u4e09\", \"\u674e\u56db\", \"\u738b\u4e94\"])))   # \u81ea\u5b9a\u4e49\u7c7b\u7684\u957f\u5ea6\nprint(len(\"abc\"))                           # \u5b57\u7b26\u4e32\u7684\u957f\u5ea6\nprint(len(&#91;1, 2, 3]))                       # \u5217\u8868\u7684\u957f\u5ea6\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd0\u884c\u7ed3\u679c\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\u6c6a\u6c6a\n\u55b5\u55b5\n\u560e\u560e\n3\n3\n3\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u6ce8\u610f\u8fd9\u4e09\u4e2a\u7c7b<strong>\u751a\u81f3\u6ca1\u6709\u5171\u540c\u7684\u7236\u7c7b<\/strong>\uff0c\u4f46 <code>chorus<\/code> \u7167\u6837\u5de5\u4f5c\u2014\u2014\u5b83\u53ea\u8981\u6c42\u300c\u5bf9\u8c61\u6709 speak \u65b9\u6cd5\u300d\u3002<code>len(x)<\/code> \u7684\u673a\u5236\u662f\u300c\u8c03\u7528 <code>x<\/code> \u7684 <code>__len__<\/code> \u65b9\u6cd5\u300d\u2014\u2014<strong>\u540c\u4e00\u51fd\u6570\u3001\u591a\u79cd\u7c7b\u578b\u3001\u5404\u81ea\u5b9e\u73b0<\/strong>\uff0c\u8fd9\u5c31\u662f\u591a\u6001\u5728\u6807\u51c6\u5e93\u91cc\u7684\u4f53\u73b0\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">2 <strong>\u540c\u4e00\u4e2a\u53d8\u91cf\uff0c\u4e0d\u540c\u9636\u6bb5\u662f\u4e0d\u540c\u5bf9\u8c61\u2014\u2014\u5206\u6d3e\u968f\u4e4b\u6539\u53d8<\/strong>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>class Animal:\n    def speak(self):\n        return \"\u52a8\u7269\u53eb\"\n\nclass Dog(Animal):\n    def speak(self):\n        return \"\u6c6a\u6c6a\"\n\nanimal = Dog()            # \u6b64\u523b animal \u662f Dog \u5bf9\u8c61\nprint(animal.speak())     # \u5206\u6d3e\u5230 Dog \u7684\u7248\u672c\nanimal = Animal()         # \u91cd\u65b0\u8d4b\u503c\u6210 Animal \u5bf9\u8c61\nprint(animal.speak())     # \u5206\u6d3e\u5230 Animal \u7684\u7248\u672c\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd0\u884c\u7ed3\u679c\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\u6c6a\u6c6a\n\u52a8\u7269\u53eb\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e24\u6b21 <code>animal.speak()<\/code> \u5199\u7684\u662f\u540c\u4e00\u884c\u4ee3\u7801\uff0c\u7ed3\u679c\u5374\u4e0d\u540c\uff0c\u56e0\u4e3a\u5206\u6d3e\u770b\u7684\u662f<strong>\u5f53\u524d\u5bf9\u8c61\u5b9e\u9645\u662f\u4ec0\u4e48\u7c7b<\/strong>\u3002\u8fd9\u5c31\u662f\u300c\u52a8\u6001\u300d\u4e8c\u5b57\uff1a\u51b3\u5b9a\u6743\u5728\u8fd0\u884c\u65f6\u3001\u5728\u5bf9\u8c61\u8eab\u4e0a\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u6613\u9519\u70b9<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u9519\u8bef\u5199\u6cd5\uff1a\u7528 if\/elif \u6328\u4e2a\u5224\u65ad\u7c7b\u578b\u518d\u8c03\u65b9\u6cd5\uff08<code>if type(x) == Dog: ...<\/code>\uff09 \u2192 \u95ee\u9898\uff1a\u6bcf\u52a0\u4e00\u4e2a\u65b0\u7c7b\u90fd\u8981\u6539\u8fd9\u6bb5\u5224\u65ad \u2192 \u6b63\u786e\u5199\u6cd5\uff1a\u8ba9\u6bcf\u4e2a\u7c7b\u81ea\u5df1\u5b9e\u73b0\u540c\u540d\u65b9\u6cd5\uff0c\u7edf\u4e00\u8c03\u7528\u3002<\/li>\n\n\n\n<li>\u9519\u8bef\u5199\u6cd5\uff1a\u8c03\u7528\u4e00\u4e2a\u5bf9\u8c61\u6ca1\u6709\u7684\u65b9\u6cd5\uff08<code>obj.fly()<\/code> \u4f46\u5bf9\u8c61\u4e0d\u4f1a\u98de\uff09 \u2192 \u95ee\u9898\uff1a\u8fd0\u884c\u65f6\u624d\u62a5 <code>AttributeError<\/code> \u2192 \u6b63\u786e\u5199\u6cd5\uff1a\u8981\u4e48\u4fdd\u8bc1\u5bf9\u8c61\u6709\u8be5\u65b9\u6cd5\uff0c\u8981\u4e48\u5148\u7528 <code>hasattr<\/code> \u68c0\u67e5\u3002<\/li>\n\n\n\n<li>\u9519\u8bef\u5199\u6cd5\uff1a\u4ee5\u4e3a\u591a\u6001\u5fc5\u987b\u7ee7\u627f\u540c\u4e00\u4e2a\u7236\u7c7b \u2192 \u95ee\u9898\uff1a\u4e0d\u9700\u8981\uff01\u6709\u540c\u540d\u65b9\u6cd5\u5373\u53ef\uff08\u9e2d\u5b50\u7c7b\u578b\uff09 \u2192 \u6b63\u786e\u5199\u6cd5\uff1a\u7ee7\u627f\u662f\u300c\u987a\u5e26\u300d\uff0c\u7ea6\u5b9a\u65b9\u6cd5\u540d\u624d\u662f\u591a\u6001\u7684\u5173\u952e\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u8bb0\u5fc6\u53e3\u8bc0<\/strong>\uff1a\u65b9\u6cd5\u8c03\u7528\u52a8\u6001\u6d3e\uff0c\u8fd0\u884c\u65f6\u770b\u5bf9\u8c61\u7c7b\uff1b\u4f1a\u53eb\u5c31\u662f\u9e2d\u5b50\uff0c\u4e0d\u5fc5\u975e\u662f\u4e00\u5bb6\u4eba\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">5 isinstance \u4e0e\u9e2d\u5b50\u7c7b\u578b \u2014\u2014 \u4e24\u79cd\u300c\u8ba4\u4eba\u300d\u65b9\u5f0f<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u662f\u4ec0\u4e48\uff1f\u4e3a\u4ec0\u4e48\u5b66\uff1f<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><code>isinstance(\u5bf9\u8c61, \u7c7b)<\/code> \u5224\u65ad\u5bf9\u8c61\u662f\u4e0d\u662f\u67d0\u4e2a\u7c7b\uff08\u6216\u5176\u5b50\u7c7b\uff09\u7684\u5b9e\u4f8b\u2014\u2014\u8fd9\u662f<strong>\u663e\u5f0f\u7c7b\u578b\u68c0\u67e5<\/strong>\uff1b\u9e2d\u5b50\u7c7b\u578b\u5219\u662f<strong>\u4e0d\u68c0\u67e5\u7c7b\u578b\u3001\u53ea\u770b\u884c\u4e3a<\/strong>\uff1a\u300c\u4f1a\u53eb\u5c31\u8ba9\u5b83\u53eb\u300d\u3002\u4e24\u79cd\u601d\u8def\u5404\u6709\u9002\u7528\u573a\u666f\uff1a\u6743\u9650\u3001\u4e13\u5c5e\u529f\u80fd\uff08\u53ea\u6709\u72d7\u8981\u6d17\u6fa1\uff09\u9002\u5408 isinstance\uff1b\u901a\u7528\u5904\u7406\uff08\u6240\u6709\u4f1a speak \u7684\u90fd\u80fd\u8868\u6f14\uff09\u9002\u5408\u9e2d\u5b50\u7c7b\u578b\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u5e95\u5c42\u539f\u7406<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><code>isinstance(obj, Cls)<\/code> \u7684\u5224\u5b9a\u4f9d\u636e\u662f\u7c7b\u578b\u5173\u7cfb\uff1a\u68c0\u67e5 <code>type(obj)<\/code> \u7684 MRO \u91cc\u6709\u6ca1\u6709 <code>Cls<\/code>\u2014\u2014\u6709\u5c31\u662f True\uff08\u6240\u4ee5\u5b50\u7c7b\u5b9e\u4f8b\u5bf9\u7236\u7c7b\u4e5f\u8fd4\u56de True\uff09\u3002\u800c\u9e2d\u5b50\u7c7b\u578b\u4e0d\u505a\u4efb\u4f55\u68c0\u67e5\uff0c\u76f4\u63a5\u8c03\u7528\u65b9\u6cd5\uff0c\u628a\u300c\u6709\u6ca1\u6709\u8fd9\u4e2a\u65b9\u6cd5\u300d\u7684\u98ce\u9669\u63a8\u8fdf\u5230\u8fd0\u884c\u65f6\u2014\u2014\u4ee3\u7801\u66f4\u7075\u6d3b\uff0c\u4f46\u9519\u8bef\u4e5f\u5728\u8fd0\u884c\u65f6\u624d\u66b4\u9732\u3002<strong>\u591a\u6001\u4f18\u5148\u7528\u9e2d\u5b50\u7c7b\u578b\uff0c\u7279\u6b8a\u60c5\u51b5\u7528 isinstance<\/strong>\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u751f\u6d3b\u7c7b\u6bd4<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">isinstance \u50cf<strong>\u770b\u8bc1\u4ef6<\/strong>\uff1a\u5148\u67e5\u8eab\u4efd\u8bc1\u786e\u8ba4\u662f\u300c\u5458\u5de5\u300d\u518d\u653e\u884c\u8fdb\u529e\u516c\u533a\uff08\u4e25\u683c\u3001\u5b89\u5168\uff09\uff1b\u9e2d\u5b50\u7c7b\u578b\u50cf<strong>\u770b\u884c\u4e3a<\/strong>\uff1a\u53ea\u8981\u4f1a\u6e38\u6cf3\u3001\u4f1a\u560e\u560e\u53eb\uff0c\u5c31\u6309\u9e2d\u5b50\u5bf9\u5f85\uff08\u5bbd\u677e\u3001\u7075\u6d3b\uff09\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u6ce8\u610f\u4e8b\u9879\u603b\u7ed3<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">1 <strong>isinstance \u7684\u56db\u79cd\u7528\u6cd5<\/strong>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>class Animal: pass\nclass Dog(Animal): pass\nclass Cat(Animal): pass\n\ndog = Dog()\nprint(isinstance(dog, Dog))            # \u662f Dog \u7684\u5b9e\u4f8b\nprint(isinstance(dog, Animal))         # \u4e5f\u662f Animal \u7684\u5b9e\u4f8b\uff08\u5b50\u7c7b\u5c5e\u4e8e\u7236\u7c7b\uff09\nprint(isinstance(dog, Cat))            # \u4e0d\u662f Cat \u7684\u5b9e\u4f8b\nprint(isinstance(dog, (Dog, Cat)))     # \u5143\u7ec4\uff1a\u5c5e\u4e8e\u5176\u4e2d\u4efb\u4e00\u5373\u53ef\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd0\u884c\u7ed3\u679c\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>True\nTrue\nFalse\nTrue\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u7b2c\u4e8c\u884c True \u662f\u7ee7\u627f\u7684\u4f53\u73b0\u2014\u2014Dog \u7684 MRO \u91cc\u6709 Animal\uff1b\u7b2c\u4e09\u884c False\uff0cDog \u548c Cat \u662f\u300c\u5144\u5f1f\u300d\uff0c\u4e92\u4e0d\u5305\u542b\uff1b\u7b2c\u56db\u884c <code>(Dog, Cat)<\/code> \u662f\u5143\u7ec4\uff0c\u5c5e\u4e8e\u5176\u4e2d<strong>\u4efb\u610f\u4e00\u4e2a<\/strong>\u7c7b\uff08\u6216\u5176\u5b50\u7c7b\uff09\u5373\u8fd4\u56de True\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">2 <strong>\u9e2d\u5b50\u7c7b\u578b\u2014\u2014\u4e0d\u67e5\u8bc1\u4ef6\uff0c\u76f4\u63a5\u5e72\u6d3b<\/strong>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>class Dog:\n    def speak(self):\n        return \"\u6c6a\u6c6a\"\n\nclass ToyDog:\n    def speak(self):\n        return \"\u6c6a\u6c6a\uff08\u73a9\u5177\u7535\u6c60\u97f3\uff09\"\n\nfor obj in (Dog(), ToyDog()):\n    print(obj.speak())    # \u4e0d\u68c0\u67e5\u7c7b\u578b\uff0c\u76f4\u63a5\u8c03\u7528\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd0\u884c\u7ed3\u679c\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\u6c6a\u6c6a\n\u6c6a\u6c6a\uff08\u73a9\u5177\u7535\u6c60\u97f3\uff09\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u771f\u72d7\u548c\u73a9\u5177\u72d7\u6ca1\u6709\u7ee7\u627f\u5173\u7cfb\uff0c\u4f46\u90fd\u300c\u4f1a\u53eb\u300d\uff0c\u6240\u4ee5\u90fd\u80fd\u8fdb\u6765\u3002<strong>\u7ea6\u5b9a\u65b9\u6cd5\u540d\uff0c\u6bd4\u7ea6\u5b9a\u7c7b\u540d\u66f4\u7075\u6d3b<\/strong>\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u6613\u9519\u70b9<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u9519\u8bef\u5199\u6cd5\uff1a<code>type(obj) == Dog<\/code> \u5224\u65ad\u7c7b\u578b \u2192 \u95ee\u9898\uff1a\u5bf9 Dog \u7684\u5b50\u7c7b\u8fd4\u56de False\uff0c\u628a\u7ee7\u627f\u5173\u7cfb\u641e\u6ca1\u4e86 \u2192 \u6b63\u786e\u5199\u6cd5\uff1a\u7528 <code>isinstance(obj, Dog)<\/code>\uff08\u542b\u5b50\u7c7b\uff09\u3002<\/li>\n\n\n\n<li>\u9519\u8bef\u5199\u6cd5\uff1a\u5230\u5904\u7528 isinstance \u505a\u5206\u652f \u2192 \u95ee\u9898\uff1a\u6bcf\u52a0\u4e00\u4e2a\u65b0\u7c7b\u90fd\u8981\u6539\u8c03\u7528\u65b9\u4ee3\u7801\uff0c\u8fdd\u80cc\u5f00\u95ed\u539f\u5219 \u2192 \u6b63\u786e\u5199\u6cd5\uff1a\u4f18\u5148\u8ba9\u6bcf\u4e2a\u7c7b\u5b9e\u73b0\u540c\u540d\u65b9\u6cd5\uff08\u591a\u6001\/\u9e2d\u5b50\u7c7b\u578b\uff09\u3002<\/li>\n\n\n\n<li>\u9519\u8bef\u5199\u6cd5\uff1aisinstance \u53c2\u6570\u5199\u53cd\uff1a<code>isinstance(Dog, obj)<\/code> \u2192 \u95ee\u9898\uff1a\u4e0d\u62a5\u9519\u4f46\u6c38\u8fdc\u8fd4\u56de False \u2192 \u6b63\u786e\u5199\u6cd5\uff1a\u987a\u5e8f\u662f <code>isinstance(\u5bf9\u8c61, \u7c7b)<\/code>\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u8bb0\u5fc6\u53e3\u8bc0<\/strong>\uff1aisinstance \u770b\u8bc1\u4ef6\uff0cMRO \u91cc\u6709\u5c31\u7b97\uff1b\u9e2d\u5b50\u7c7b\u578b\u770b\u884c\u4e3a\uff0c\u76f4\u63a5\u8c03\u7528\u4e0d\u8bbe\u9632\uff1b\u80fd\u591a\u6001\u5c31\u591a\u6001\uff0c\u4e13\u5c5e\u529f\u80fd\u518d\u67e5\u8bc1\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">6 \u52a8\u624b\u5b9e\u8df5\uff1a\u52a8\u7269\u7c7b\u7ee7\u627f\u4f53\u7cfb<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u628a\u4eca\u5929\u7684\u5185\u5bb9\u4e32\u6210\u4e00\u4e2a\u5b8c\u6574\u7684\u52a8\u7269\u4e16\u754c\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code># animals.py \u2014\u2014 \u52a8\u7269\u7c7b\u7ee7\u627f\u4f53\u7cfb\nclass Animal:\n    \"\"\"\u6240\u6709\u52a8\u7269\u7684\u57fa\u7c7b\"\"\"\n    def __init__(self, name):\n        self.name = name\n\n    def speak(self):\n        return f\"{self.name} \u53d1\u51fa\u53eb\u58f0\"\n\n    def move(self):\n        return f\"{self.name} \u52a8\u4e86\u4e00\u4e0b\"\n\n    def __str__(self):\n        return f\"{type(self).__name__}\uff1a{self.name}\"\n\n\nclass Dog(Animal):\n    def speak(self):\n        return f\"{self.name}\uff1a\u6c6a\u6c6a\uff01\"\n\n    def move(self):\n        return f\"{self.name} \u6447\u7740\u5c3e\u5df4\u8dd1\u8d77\u6765\u4e86\"\n\n\nclass Cat(Animal):\n    def speak(self):\n        return f\"{self.name}\uff1a\u55b5\u55b5\uff5e\"\n\n    def move(self):\n        return f\"{self.name} \u8f7b\u5de7\u5730\u8df3\u4e0a\u4e86\u6c99\u53d1\"\n\n\ndef animal_show(animals):\n    \"\"\"\u591a\u6001\u6f14\u793a\uff1a\u540c\u6837\u7684\u8c03\u7528\uff0c\u4e0d\u540c\u7684\u8868\u73b0\"\"\"\n    print(\"--- \u52a8\u7269\u56ed\u8868\u6f14\u5f00\u59cb ---\")\n    for animal in animals:\n        print(animal)\n        print(animal.speak())\n        print(animal.move())\n\n\nif __name__ == \"__main__\":\n    dog = Dog(\"\u65fa\u8d22\")\n    cat = Cat(\"\u54aa\u54aa\")\n    animal_show(&#91;dog, cat])\n\n    # isinstance \u6f14\u793a\n    print(isinstance(dog, Animal))   # True\n    print(isinstance(cat, Dog))      # False\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd0\u884c\u7ed3\u679c\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>--- \u52a8\u7269\u56ed\u8868\u6f14\u5f00\u59cb ---\nDog\uff1a\u65fa\u8d22\n\u65fa\u8d22\uff1a\u6c6a\u6c6a\uff01\n\u65fa\u8d22 \u6447\u7740\u5c3e\u5df4\u8dd1\u8d77\u6765\u4e86\nCat\uff1a\u54aa\u54aa\n\u54aa\u54aa\uff1a\u55b5\u55b5\uff5e\n\u54aa\u54aa \u8f7b\u5de7\u5730\u8df3\u4e0a\u4e86\u6c99\u53d1\nTrue\nFalse\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u6ce8\u610f <code>animal_show<\/code> \u91cc\u8c03\u7528 <code>animal.speak()<\/code> \u548c <code>animal.move()<\/code>\uff0c\u72d7\u548c\u732b\u5404\u81ea\u6267\u884c\u81ea\u5df1\u7684\u7248\u672c\u2014\u2014\u8fd9\u5c31\u662f\u591a\u6001\u3002\u4ee5\u540e\u60f3\u52a0 <code>Bird<\/code> \u7c7b\uff0c\u53ea\u9700\u7ee7\u627f <code>Animal<\/code> \u5e76\u91cd\u5199\u65b9\u6cd5\uff0c\u8868\u6f14\u51fd\u6570\u96f6\u6539\u52a8\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u5347\u7ea7\u6311\u6218<\/strong>\uff1a\u65b0\u589e <code>Bird<\/code> \u7c7b\uff08\u4f1a\u98de\uff0c\u53ef\u4ee5\u52a0 <code>fly()<\/code> \u65b9\u6cd5\uff09\uff0c\u52a0\u5165\u8868\u6f14\uff1b\u518d\u7ed9 <code>Shape<\/code> \u4f53\u7cfb\u52a0\u4e00\u4e2a <code>Triangle<\/code> \u7c7b\uff0c\u7b97\u4e09\u89d2\u5f62\u9762\u79ef\uff08\u5e95\u00d7\u9ad8\u00f72\uff09\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u4eca\u65e5\u603b\u7ed3<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u7ee7\u627f\u7684\u672c\u8d28\uff1a\u5b50\u7c7b\u4e0d\u590d\u5236\u4ee3\u7801\uff0c\u8c03\u7528\u65f6\u6cbf MRO\uff08\u81ea\u5df1 \u2192 \u7236\u7c7b \u2192 object\uff09\u67e5\u627e\u5e76\u501f\u7528\u7236\u7c7b\u65b9\u6cd5\n\u5b50\u7c7b\u91cd\u5199 <code>__init__<\/code> \u540e\u7236\u7c7b\u7684\u4e0d\u4f1a\u81ea\u52a8\u6267\u884c\uff0c\u8981\u5148 <code>super().__init__(...)<\/code>\uff0c\u4e14\u8c03\u7528\u65f6\u4e0d\u8981\u4f20 self\n\u91cd\u5199 = \u7528\u81ea\u5df1\u7684\u540c\u540d\u65b9\u6cd5\u6cbf MRO\u300c\u6321\u4f4f\u300d\u7236\u7c7b\u7248\u672c\uff1b\u8981\u4fdd\u7559\u7236\u7c7b\u884c\u4e3a\u7528 <code>super().\u65b9\u6cd5\u540d(...)<\/code>\n\u591a\u6001 = \u8fd0\u884c\u65f6\u52a8\u6001\u5206\u6d3e\uff1a<code>obj.\u65b9\u6cd5()<\/code> \u6309\u5bf9\u8c61\u7684\u5b9e\u9645\u7c7b\u578b\u9009\u62e9\u7248\u672c\uff0c\u65b0\u7c7b\u96f6\u6539\u52a8\u5373\u53ef\u63a5\u5165\n\u80fd\u5199\u51fa\u300c\u6a21\u677f\u65b9\u6cd5\u300d\u5f0f\u4ee3\u7801\uff1a\u7236\u7c7b\u5b9a\u6d41\u7a0b\uff0c\u5b50\u7c7b\u91cd\u5199\u7ec6\u8282\n<code>isinstance(obj, \u7c7b)<\/code> \u68c0\u67e5 MRO\uff0c\u5b50\u7c7b\u5b9e\u4f8b\u5bf9\u7236\u7c7b\u4e5f\u8fd4\u56de True\uff1b\u5143\u7ec4\u53c2\u6570\u8868\u793a\u300c\u4efb\u4e00\u5373\u53ef\u300d\n\u80fd\u533a\u5206\u9e2d\u5b50\u7c7b\u578b\uff08\u770b\u884c\u4e3a\u3001\u76f4\u63a5\u8c03\u7528\uff09\u4e0e isinstance\uff08\u770b\u8bc1\u4ef6\u3001\u6309\u7c7b\u578b\u5206\u6d41\uff09\uff0c\u77e5\u9053\u4f18\u5148\u591a\u6001\n\u5b8c\u6210\u52a8\u7269\u7c7b\u7ee7\u627f\u4f53\u7cfb\uff0c\u5e76\u5c1d\u8bd5\u65b0\u589e Bird \u7c7b\u3001Triangle \u7c7b<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>\u62a5\u9519<\/th><th>\u539f\u56e0<\/th><th>\u4fee\u590d<\/th><\/tr><\/thead><tbody><tr><td><code>TypeError: __init__() missing 1 required positional argument<\/code><\/td><td>\u5b50\u7c7b\u5b9a\u4e49\u4e86 <code>__init__<\/code> \u5374\u6ca1\u8c03 <code>super().__init__<\/code>\uff0c\u7236\u7c7b\u53c2\u6570\u6ca1\u4f20<\/td><td>\u5728\u5b50\u7c7b <code>__init__<\/code> \u91cc\u5148 <code>super().__init__(...)<\/code><\/td><\/tr><tr><td><code>AttributeError: 'Dog' object has no attribute 'name'<\/code><\/td><td>\u5b50\u7c7b\u91cd\u5199\u4e86 <code>__init__<\/code> \u4f46\u6f0f\u4e86\u7236\u7c7b\u5c5e\u6027\u521d\u59cb\u5316<\/td><td>\u8c03\u7528 <code>super().__init__(name)<\/code> \u6216\u81ea\u5df1\u521d\u59cb\u5316<\/td><\/tr><tr><td><code>TypeError: Class() takes no arguments<\/code><\/td><td>\u8bef\u628a\u7c7b\u5f53\u51fd\u6570\u8c03\u7528\u5e76\u4f20\u53c2<\/td><td>\u68c0\u67e5\u6784\u9020\u65b9\u6cd5\u662f\u5426\u5199\u6210\u4e86\u666e\u901a\u51fd\u6570\uff08\u5c11 <code>self<\/code>\uff09<\/td><\/tr><tr><td><code>NameError<\/code>\uff08\u5b50\u7c7b\u65b9\u6cd5\u91cc\u7528\u9519\u53d8\u91cf\u540d\uff09<\/td><td>\u62fc\u5199\u4e0d\u4e00\u81f4\uff0c\u6216\u60f3\u7528\u7236\u7c7b\u5c5e\u6027\u5374\u5199\u6210\u4e86\u5c40\u90e8\u53d8\u91cf<\/td><td>\u6838\u5bf9 <code>self.xxx<\/code> \u7684\u62fc\u5199<\/td><\/tr><tr><td><code>isinstance<\/code> \u8fd4\u56de False \u4f46\u671f\u671b True<\/td><td>\u5224\u65ad\u7684\u7c7b\u5199\u53cd\u4e86\uff0c\u6216\u7528\u9519\u7c7b<\/td><td>\u786e\u8ba4\u662f <code>isinstance(\u5bf9\u8c61, \u7236\u7c7b\u6216\u672c\u7c7b)<\/code><\/td><\/tr><\/tbody><\/table><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>1 \u7ee7\u627f\u7684\u672c\u8d28 \u2014\u2014 \u5b50\u7c7b\u4e3a\u4ec0\u4e48\u300c\u81ea\u52a8\u62e5\u6709\u300d\u7236\u7c7b\u7684\u65b9\u6cd5 \u662f\u4ec0\u4e48\uff1f\u4e3a\u4ec0\u4e48\u5b66\uff1f \u7ee7\u627f\uff08inheritance\uff09\u8ba9\u4e00 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_import_markdown_pro_load_document_selector":0,"_import_markdown_pro_submit_text_textarea":"","footnotes":""},"categories":[16,9],"tags":[17],"class_list":["post-98","post","type-post","status-publish","format-standard","hentry","category-python","category-code-dev","tag-python-day"],"_links":{"self":[{"href":"https:\/\/ltrainyard.icu\/index.php\/wp-json\/wp\/v2\/posts\/98","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ltrainyard.icu\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ltrainyard.icu\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ltrainyard.icu\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ltrainyard.icu\/index.php\/wp-json\/wp\/v2\/comments?post=98"}],"version-history":[{"count":2,"href":"https:\/\/ltrainyard.icu\/index.php\/wp-json\/wp\/v2\/posts\/98\/revisions"}],"predecessor-version":[{"id":145,"href":"https:\/\/ltrainyard.icu\/index.php\/wp-json\/wp\/v2\/posts\/98\/revisions\/145"}],"wp:attachment":[{"href":"https:\/\/ltrainyard.icu\/index.php\/wp-json\/wp\/v2\/media?parent=98"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ltrainyard.icu\/index.php\/wp-json\/wp\/v2\/categories?post=98"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ltrainyard.icu\/index.php\/wp-json\/wp\/v2\/tags?post=98"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}