{"id":96,"date":"2026-08-06T00:29:18","date_gmt":"2026-08-05T16:29:18","guid":{"rendered":"https:\/\/ltrainyard.icu\/?p=96"},"modified":"2026-08-06T00:44:28","modified_gmt":"2026-08-05T16:44:28","slug":"day-15-%e7%b1%bb%e4%b8%8e%e5%af%b9%e8%b1%a1%ef%bc%9a%e6%95%b0%e6%8d%ae-%e8%a1%8c%e4%b8%ba%ef%bc%88class-__init__-self%ef%bc%89","status":"publish","type":"post","link":"https:\/\/ltrainyard.icu\/index.php\/2026\/08\/06\/day-15-%e7%b1%bb%e4%b8%8e%e5%af%b9%e8%b1%a1%ef%bc%9a%e6%95%b0%e6%8d%ae-%e8%a1%8c%e4%b8%ba%ef%bc%88class-__init__-self%ef%bc%89\/","title":{"rendered":"| Day 15 | \u7c7b\u4e0e\u5bf9\u8c61\uff1a\u6570\u636e + \u884c\u4e3a\uff08class \/ __init__ \/ self\uff09 |"},"content":{"rendered":"\n<h3 class=\"wp-block-heading\">1 \u7c7b\u4e0e\u5bf9\u8c61 \u2014\u2014 \u300c\u6570\u636e + \u884c\u4e3a\u300d\u662f\u600e\u4e48\u7ed1\u5728\u4e00\u8d77\u7684<\/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>\u7c7b<\/strong>\uff08class\uff09\u662f<strong>\u6a21\u677f<\/strong>\uff0c<strong>\u5bf9\u8c61<\/strong>\uff08object\uff09\u662f\u6839\u636e\u6a21\u677f\u9020\u51fa\u6765\u7684<strong>\u5177\u4f53\u5b9e\u4f8b<\/strong>\u3002\u4e00\u4e2a\u5bf9\u8c61\u628a\u300c\u6570\u636e\uff08\u5c5e\u6027\uff09\u300d\u548c\u300c\u884c\u4e3a\uff08\u65b9\u6cd5\uff09\u300d\u88c5\u8fdb\u540c\u4e00\u4e2a\u5305\u91cc\uff1a<code>account.balance<\/code> \u662f\u5b83\u7684\u6570\u636e\uff0c<code>account.deposit()<\/code> \u662f\u5b83\u7684\u884c\u4e3a\u3002\u4e4b\u524d\u6211\u4eec\u5b66\u7684\u90fd\u662f\u300c\u6570\u636e + \u51fd\u6570\u300d\uff1a\u6570\u636e\u653e\u53d8\u91cf\u91cc\uff0c\u51fd\u6570\u5904\u7406\u6570\u636e\uff1b\u4f46\u771f\u5b9e\u4e16\u754c\u91cc\u7684\u4e1c\u897f\u662f\u300c\u6570\u636e + \u884c\u4e3a\u300d\u4e00\u4f53\u7684\u2014\u2014\u4e00\u4e2a\u94f6\u884c\u8d26\u6237\u65e2\u6709\u4f59\u989d\uff08\u6570\u636e\uff09\uff0c\u53c8\u6709\u5b58\u6b3e\u3001\u53d6\u6b3e\uff08\u884c\u4e3a\uff09\u3002\u9762\u5411\u5bf9\u8c61\u7f16\u7a0b\uff08OOP\uff09\u5c31\u662f\u628a\u8fd9\u4fe9\u7ed1\u5728\u4e00\u8d77\uff0c\u8ba9\u4ee3\u7801\u66f4\u8d34\u8fd1\u73b0\u5b9e\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\">Python \u91cc<strong>\u4e00\u5207\u7686\u5bf9\u8c61<\/strong>\uff1a\u53d8\u91cf\u5b58\u7684\u662f\u6307\u5411\u5bf9\u8c61\u7684\u5f15\u7528\uff0c\u6bcf\u4e2a\u5bf9\u8c61\u5185\u90e8\u6709\u4e00\u4e2a\u300c\u5c5e\u6027\u5b57\u5178\u300d\uff08<code>__dict__<\/code>\uff09\uff0c\u5c5e\u6027\u540d \u2192 \u5c5e\u6027\u503c\u90fd\u5b58\u5728\u8fd9\u91cc\uff1b\u8bbf\u95ee <code>obj.attr<\/code> \u5148\u67e5\u5bf9\u8c61\u81ea\u5df1\u7684 <code>__dict__<\/code>\uff0c\u67e5\u4e0d\u5230\u518d\u67e5\u7c7b\u7684 <code>__dict__<\/code>\uff08Day 16 \u5b66\u7ee7\u627f\u540e\u8fd8\u4f1a\u7ee7\u7eed\u5f80\u7236\u7c7b\u67e5\uff09\u3002\u300c\u5bf9\u8c61 = \u6570\u636e + \u884c\u4e3a\u300d\u5728\u5e95\u5c42\u5c31\u662f\u4e24\u4e2a\u5b57\u5178\u7684\u914d\u5408\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\">\u7c7b\u50cf<strong>\u4ea7\u54c1\u6a21\u5177<\/strong>\uff0c\u5bf9\u8c61\u50cf<strong>\u6a21\u5177\u538b\u51fa\u6765\u7684\u4ea7\u54c1<\/strong>\uff1a\u6a21\u5177\u672c\u8eab\u4e0d\u80fd\u5356\u94b1\uff0c\u4f46\u6bcf\u4e00\u4e2a\u4ea7\u54c1\u90fd\u6309\u6a21\u5177\u7684\u5f62\u72b6\u51fa\u5382\uff0c\u5e76\u4e14\u81ea\u5e26\u6a21\u5177\u523b\u597d\u7684\u300c\u4f7f\u7528\u8bf4\u660e\u300d\uff08\u65b9\u6cd5\uff09\u3002\u4e00\u4e2a\u6a21\u5177\u53ef\u4ee5\u538b\u51fa\u6210\u5343\u4e0a\u4e07\u4e2a\u4e92\u4e0d\u76f8\u540c\u7684\u4ea7\u54c1\u2014\u2014\u6bcf\u4e2a\u4ea7\u54c1\u6709\u81ea\u5df1\u7684\u7f16\u53f7\uff08\u5c5e\u6027\uff09\uff0c\u4f46\u90fd\u5177\u5907\u540c\u4e00\u79cd\u529f\u80fd\uff08\u65b9\u6cd5\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>\u4e24\u4e2a\u5bf9\u8c61\u662f\u4e24\u4e2a\u72ec\u7acb\u7684\u300c\u5305\u300d\uff0c\u4e92\u4e0d\u5f71\u54cd<\/strong>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>class Dog:\n    pass\n\ndog1 = Dog()\ndog2 = Dog()\nprint(dog1 is dog2)          # \u662f\u4e0d\u662f\u540c\u4e00\u4e2a\u5bf9\u8c61\uff1f\u4e0d\u662f\nprint(id(dog1), id(dog2))    # \u5185\u5b58\u5730\u5740\u4e0d\u540c\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>False\n\u793a\u4f8b\u8f93\u51fa\uff08\u5185\u5b58\u5730\u5740\u6bcf\u6b21\u8fd0\u884c\u90fd\u4e0d\u540c\uff09\uff1a2345678901234 2345678905678\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><code>class Dog:<\/code> \u5b9a\u4e49\u7c7b\uff0c<code>pass<\/code> \u8868\u793a\u6682\u65f6\u4ec0\u4e48\u90fd\u4e0d\u505a\uff08\u5360\u4f4d\uff09\u3002<code>Dog()<\/code> \u52a0\u62ec\u53f7\u624d\u662f\u5728\u300c\u9020\u5bf9\u8c61\u300d\u2014\u2014<strong>\u7c7b\u662f\u6a21\u677f\uff0c\u52a0\u62ec\u53f7\u624d\u662f\u751f\u4ea7<\/strong>\u3002<code>dog1 is dog2<\/code> \u4e3a False\uff0c\u8bc1\u660e\u5b83\u4eec\u662f\u4e24\u4e2a\u72ec\u7acb\u7684\u5bf9\u8c61\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">2 **\u5bf9\u8c61\u5185\u90e8\u7684\u5c5e\u6027\u5b57\u5178 <strong>dict<\/strong>**\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>class Dog:\n    def __init__(self, name):\n        self.name = name\n\ndog = Dog(\"\u65fa\u8d22\")\nprint(dog.__dict__)   # \u5c5e\u6027\u90fd\u88c5\u5728\u8fd9\u4e2a\u5b57\u5178\u91cc\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>{'name': '\u65fa\u8d22'}\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u5bf9\u8c61\u672c\u8d28\u4e0a\u5c31\u662f\u4e00\u4e2a\u5e26\u540d\u5b57\u7684\u5b57\u5178<\/strong>\uff0c\u53ea\u4e0d\u8fc7\u8bbf\u95ee\u65f6\u5199 <code>dog.name<\/code> \u800c\u4e0d\u662f <code>dog[\"name\"]<\/code>\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">3 <strong>obj.attr \u7684\u67e5\u627e\u987a\u5e8f\u2014\u2014\u5148\u627e\u81ea\u5df1\uff0c\u518d\u627e\u7c7b<\/strong>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>class Dog:\n    species = \"\u72ac\u79d1\"     # \u7c7b\u5c5e\u6027\uff1a\u6240\u6709\u72d7\u5171\u4eab\n\ndog = Dog()\nprint(dog.species)     # \u81ea\u5df1\u6ca1\u5b9a\u4e49\uff0c\u53bb\u7c7b\u91cc\u627e\uff0c\u627e\u5230\"\u72ac\u79d1\"\ndog.species = \"\u54c8\u58eb\u5947\"  # \u7ed9\u81ea\u5df1\u5355\u72ec\u5b58\u4e00\u4efd\nprint(dog.species)     # \u73b0\u5728\u81ea\u5df1\u6709\uff0c\u7528\u81ea\u5df1\u8fd9\u4efd\nprint(Dog.species)     # \u7c7b\u91cc\u90a3\u4efd\u8fd8\u662f\"\u72ac\u79d1\"\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>\u72ac\u79d1\n\u54c8\u58eb\u5947\n\u72ac\u79d1\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><code>dog.species = \"\u54c8\u58eb\u5947\"<\/code> \u662f<strong>\u5728\u5bf9\u8c61\u81ea\u5df1\u8eab\u4e0a\u65b0\u5efa\u4e00\u4e2a\u5c5e\u6027<\/strong>\uff0c\u5e76\u4e0d\u6539\u52a8\u7c7b\u91cc\u7684\u90a3\u4efd\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>dog = Dog<\/code>\uff08\u5fd8\u52a0\u62ec\u53f7\uff09 \u2192 \u95ee\u9898\uff1adog \u53d8\u6210\u7c7b\u672c\u8eab\u800c\u4e0d\u662f\u5bf9\u8c61\uff0c\u8bbf\u95ee\u5c5e\u6027\u62a5\u9519 \u2192 \u6b63\u786e\u5199\u6cd5\uff1a\u9020\u5bf9\u8c61\u5fc5\u987b\u52a0\u62ec\u53f7\uff1a<code>dog = Dog()<\/code>\u3002<\/li>\n\n\n\n<li>\u9519\u8bef\u5199\u6cd5\uff1a\u7c7b\u540d\u7528\u5c0f\u5199\uff1a<code>class dog:<\/code> \u2192 \u95ee\u9898\uff1a\u4e0d\u62a5\u9519\u4f46\u8fdd\u80cc\u7ea6\u5b9a\uff0c\u522b\u4eba\u770b\u4e0d\u61c2 \u2192 \u6b63\u786e\u5199\u6cd5\uff1a\u7c7b\u540d\u7528\u9a7c\u5cf0\u5f0f\u5927\u5199\u5f00\u5934\uff1a<code>class Dog:<\/code>\u3002<\/li>\n\n\n\n<li>\u9519\u8bef\u5199\u6cd5\uff1a\u4ee5\u4e3a <code>dog1 = Dog(); dog2 = Dog()<\/code> \u662f\u540c\u4e00\u4e2a\u5bf9\u8c61 \u2192 \u95ee\u9898\uff1a\u662f\u4e24\u4e2a\u72ec\u7acb\u5bf9\u8c61\uff0c\u4e92\u4e0d\u5f71\u54cd \u2192 \u6b63\u786e\u5199\u6cd5\uff1a\u60f3\u8981\u540c\u4e00\u4e2a\u5bf9\u8c61\uff1a<code>dog2 = dog1<\/code>\uff08\u590d\u5236\u5f15\u7528\uff09\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u8bb0\u5fc6\u53e3\u8bc0<\/strong>\uff1a\u7c7b\u662f\u6a21\u5177\u5bf9\u8c61\u662f\u8d27\uff0c\u52a0\u62ec\u53f7\u624d\u51fa\u8d27\uff1b\u5148\u67e5\u81ea\u5df1\u518d\u67e5\u7c7b\uff0c\u5c5e\u6027\u5b57\u5178\u88c5\u4e00\u5207\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">2 <strong>init<\/strong> \u7684\u771f\u76f8 \u2014\u2014 \u521b\u5efa\u5bf9\u8c61\u65f6\u53d1\u751f\u4e86\u4ec0\u4e48<\/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>__init__<\/code> \u662f<strong>\u6784\u9020\u65b9\u6cd5<\/strong>\uff08\u66f4\u51c6\u786e\u8bf4\u662f\u300c\u521d\u59cb\u5316\u65b9\u6cd5\u300d\uff09\uff1a\u521b\u5efa\u5bf9\u8c61\u65f6\u81ea\u52a8\u6267\u884c\uff0c\u7528\u6765\u7ed9\u65b0\u5bf9\u8c61\u8bbe\u7f6e\u521d\u59cb\u5c5e\u6027\u3002\u6ca1\u6709\u5b83\uff0c\u4f60\u5f97\u521b\u5efa\u5b8c\u5bf9\u8c61\u518d\u624b\u52a8\u8865\u5c5e\u6027\uff0c\u5fd8\u8865\u5c31\u62a5 <code>AttributeError<\/code>\uff1b\u6709\u4e86\u5b83\uff0c\u300c\u9020\u51fa\u6765\u7684\u5bf9\u8c61\u4e00\u5b9a\u521d\u59cb\u5316\u597d\u4e86\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\"><code>Dog(\"\u65fa\u8d22\", 3)<\/code> \u8fd9\u4e00\u884c\u5b9e\u9645\u505a\u4e86\u4e24\u6b65\uff1a\u7b2c\u4e00\u6b65 <code>__new__<\/code>\uff08\u5206\u914d\u4e00\u5757\u5185\u5b58\uff0c\u5f97\u5230\u4e00\u4e2a\u300c\u7a7a\u767d\u5bf9\u8c61\u300d\uff09\uff0c\u7b2c\u4e8c\u6b65\u81ea\u52a8\u8c03\u7528 <code>__init__<\/code>\uff08\u7ed9\u8fd9\u5757\u7a7a\u767d\u5bf9\u8c61\u586b\u4e0a\u6570\u636e\uff09\u3002<code>__init__<\/code> \u7684\u7b2c\u4e00\u4e2a\u53c2\u6570 <code>self<\/code> \u5c31\u662f\u7b2c\u4e00\u6b65\u5206\u914d\u51fa\u6765\u7684\u90a3\u4e2a\u7a7a\u767d\u5bf9\u8c61\u672c\u8eab\u3002\u6ce8\u610f <code>__init__<\/code> <strong>\u4e0d\u80fd return \u975e None \u7684\u503c<\/strong>\u2014\u2014\u5b83\u53ea\u8d1f\u8d23\u300c\u586b\u6570\u636e\u300d\uff0c\u4e0d\u8d1f\u8d23\u300c\u4ea4\u51fa\u65b0\u5bf9\u8c61\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\">\u50cf<strong>\u5165\u4f4f\u9152\u5e97<\/strong>\uff1a<code>__new__<\/code> \u662f\u524d\u53f0\u5148\u7ed9\u4f60\u5f00\u597d\u4e00\u95f4\u623f\uff08\u62ff\u5230\u623f\u5361\uff09\uff0c<code>__init__<\/code> \u662f\u4f60\u8fdb\u623f\u95f4\u540e\u628a\u884c\u674e\u6446\u597d\uff08\u653e\u597d\u5c5e\u6027\uff09\u3002\u4f60\u53ea\u9700\u8981\u5bf9\u524d\u53f0\u8bf4\u4e00\u53e5 <code>Dog(\"\u65fa\u8d22\", 3)<\/code>\uff0c\u5f00\u623f\u548c\u5e03\u7f6e\u90fd\u81ea\u52a8\u5b8c\u6210\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><strong>init<\/strong> \u662f\u81ea\u52a8\u8c03\u7528\u7684\u2014\u2014\u770b\u6267\u884c\u987a\u5e8f<\/strong>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>class Dog:\n    def __init__(self, name):\n        print(\"\u5f00\u59cb\u521d\u59cb\u5316\u4e00\u4e2a\u72d7\u5bf9\u8c61\u2026\u2026\")\n        self.name = name\n        print(\"\u521d\u59cb\u5316\u5b8c\u6210\uff0c\u540d\u5b57\u662f\", self.name)\n\ndog = Dog(\"\u65fa\u8d22\")\nprint(\"\u521b\u5efa\u8bed\u53e5\u6267\u884c\u5b8c\u4e86\")\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>\u5f00\u59cb\u521d\u59cb\u5316\u4e00\u4e2a\u72d7\u5bf9\u8c61\u2026\u2026\n\u521d\u59cb\u5316\u5b8c\u6210\uff0c\u540d\u5b57\u662f \u65fa\u8d22\n\u521b\u5efa\u8bed\u53e5\u6267\u884c\u5b8c\u4e86\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><code>Dog(\"\u65fa\u8d22\")<\/code> \u8fd9\u884c\u4ee3\u7801\u4e00\u6267\u884c\uff0c<code>__init__<\/code> \u91cc\u7684\u5185\u5bb9<strong>\u62a2\u5148<\/strong>\u8dd1\u5b8c\uff0c\u7136\u540e\u624d\u6267\u884c\u4e0b\u4e00\u884c\u2014\u2014\u8bc1\u660e\u5b83\u662f\u521b\u5efa\u6d41\u7a0b\u91cc\u81ea\u52a8\u89e6\u53d1\u7684\u4e00\u73af\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">2 <strong>\u53c2\u6570 \u2192 \u5c5e\u6027\u7684\u4f20\u9012\u8fc7\u7a0b<\/strong>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>class Dog:\n    def __init__(self, name, age):\n        self.name = name    # \u53c2\u6570 name \u4f20\u8fdb\u6765\uff0c\u5b58\u6210\u5c5e\u6027 self.name\n        self.age = age      # \u53c2\u6570 age \u4f20\u8fdb\u6765\uff0c\u5b58\u6210\u5c5e\u6027 self.age\n\ndog = Dog(\"\u65fa\u8d22\", 3)\nprint(dog.name, dog.age)\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>\u65fa\u8d22 3\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><code>Dog(\"\u65fa\u8d22\", 3)<\/code> \u91cc\u7684\u4e24\u4e2a\u62ec\u53f7\u53c2\u6570\uff0c\u4f1a<strong>\u539f\u6837\u4f20\u7ed9 <code>__init__<\/code> \u7684\u5f62\u53c2<\/strong>\u3002\u8bb0\u4f4f\uff1a<strong>\u5e26 self. \u7684\u662f\u5c5e\u6027\uff0c\u4e0d\u5e26\u7684\u662f\u53c2\u6570<\/strong>\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">3 <strong>\u9ed8\u8ba4\u53c2\u6570\u2014\u2014\u6709\u7684\u5c5e\u6027\u53ef\u4ee5\u300c\u4e0d\u4f20\u300d<\/strong>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>class BankAccount:\n    def __init__(self, owner, balance=0):\n        self.owner = owner\n        self.balance = balance\n\na = BankAccount(\"\u5f20\u4e09\")\nb = BankAccount(\"\u674e\u56db\", 500)\nprint(a.owner, a.balance)\nprint(b.owner, b.balance)\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>\u5f20\u4e09 0\n\u674e\u56db 500\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><code>balance=0<\/code> \u662f\u9ed8\u8ba4\u53c2\u6570\uff08Day 8 \u5b66\u8fc7\uff09\uff0c\u5f00\u6237\u65f6\u4e0d\u4f20\u4f59\u989d\u5c31\u662f 0\u3002\u300c\u6784\u9020\u65b9\u6cd5 + \u9ed8\u8ba4\u53c2\u6570\u300d\u7684\u7ecf\u5178\u7ec4\u5408\u8ba9\u7c7b\u7684\u4f7f\u7528\u66f4\u7075\u6d3b\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>__init__<\/code> \u91cc\u5199 <code>return \"hello\"<\/code> \u2192 \u95ee\u9898\uff1a\u62a5 <code>TypeError: __init__() should return None<\/code> \u2192 \u6b63\u786e\u5199\u6cd5\uff1a<code>__init__<\/code> \u53ea\u8d4b\u503c\uff0c\u4e0d return\uff08\u6216 <code>return None<\/code>\uff09\u3002<\/li>\n\n\n\n<li>\u9519\u8bef\u5199\u6cd5\uff1a\u5c5e\u6027\u62fc\u5199\u4e0d\u4e00\u81f4\uff1a<code>self.name = name<\/code> \u5374\u8bbf\u95ee <code>dog.nmae<\/code> \u2192 \u95ee\u9898\uff1a\u62a5 <code>AttributeError: 'Dog' object has no attribute 'nmae'<\/code> \u2192 \u6b63\u786e\u5199\u6cd5\uff1a\u5c5e\u6027\u540d\u7edf\u4e00\uff0c\u5199\u5b8c\u68c0\u67e5\u62fc\u5199\u3002<\/li>\n\n\n\n<li>\u9519\u8bef\u5199\u6cd5\uff1a\u521b\u5efa\u65f6\u5c11\u4f20\u53c2\u6570\uff1a<code>Dog(\"\u65fa\u8d22\")<\/code> \u4f46 <code>__init__<\/code> \u8981\u4e24\u4e2a\u53c2\u6570 \u2192 \u95ee\u9898\uff1a\u62a5 <code>TypeError: __init__() missing 1 required positional argument<\/code> \u2192 \u6b63\u786e\u5199\u6cd5\uff1a\u53c2\u6570\u4e2a\u6570\u5bf9\u9f50\uff0c\u6216\u7528\u9ed8\u8ba4\u53c2\u6570\u515c\u5e95\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u8bb0\u5fc6\u53e3\u8bc0<\/strong>\uff1anew \u5f00\u623f init \u6446\u884c\u674e\uff0c\u81ea\u52a8\u6267\u884c\u4e0d\u7528\u4f60\u7ba1\uff1b\u5e26 self. \u662f\u5c5e\u6027\uff0c\u4e0d\u5e26\u662f\u53c2\u6570\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">3 self \u7684\u672c\u8d28 \u2014\u2014 \u65b9\u6cd5\u91cc\u7684\u300c\u6211\u81ea\u5df1\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>self<\/code> \u662f\u5b9e\u4f8b\u65b9\u6cd5\u7684\u7b2c\u4e00\u4e2a\u53c2\u6570\uff0c\u4ee3\u8868<strong>\u8c03\u7528\u8fd9\u4e2a\u65b9\u6cd5\u7684\u90a3\u4e2a\u5bf9\u8c61<\/strong>\u3002\u4e0d\u5b66 self\uff0c\u4f60\u53ea\u80fd\u628a\u6bcf\u4e2a\u5bf9\u8c61\u7684\u6570\u636e\u90fd\u5199\u6210\u5168\u5c40\u53d8\u91cf\uff08\u4e92\u76f8\u4e32\u5473\uff09\uff1b\u5b66\u4f1a self\uff0c\u65b9\u6cd5\u5185\u90e8\u7528 <code>self.xxx<\/code> \u8bfb\u5199\u7684\u5c31\u662f\u300c\u5f53\u524d\u8fd9\u4e2a\u5bf9\u8c61\u300d\u7684\u5c5e\u6027\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\">\u65b9\u6cd5\u5176\u5b9e\u5c31\u662f\u300c\u7c7b\u91cc\u5b9a\u4e49\u7684\u51fd\u6570\u300d\u3002\u8c03\u7528 <code>dog.bark()<\/code> \u65f6\uff0cPython \u505a\u4e86\u4e24\u4ef6\u4e8b\uff1a\u5148\u627e\u5230 <code>dog<\/code> \u7684\u7c7b\u91cc\u7684 <code>bark<\/code> \u51fd\u6570\uff0c\u7136\u540e<strong>\u628a <code>dog<\/code> \u81ea\u5df1\u4f5c\u4e3a\u7b2c\u4e00\u4e2a\u53c2\u6570\u4f20\u8fdb\u53bb<\/strong>\u3002\u6240\u4ee5 <code>dog.bark()<\/code> \u4e0e <code>Dog.bark(dog)<\/code> \u5b8c\u5168\u7b49\u4ef7\u2014\u2014\u524d\u8005\u662f\u8bed\u6cd5\u7cd6\uff08\u5199\u6cd5\u4e0a\u7684\u7b80\u5199\uff09\uff0c\u540e\u8005\u662f\u5b83\u80cc\u540e\u7684\u771f\u76f8\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\">self \u50cf<strong>\u5bf9\u8bb2\u673a\u91cc\u558a\u300c\u6211\u662f\u300d<\/strong>\uff1a\u5168\u73ed\u540c\u5b66\u5171\u7528\u540c\u4e00\u5957\u300c\u56de\u7b54\u95ee\u9898\u300d\u7684\u89c4\u5219\uff08\u65b9\u6cd5\u53ea\u6709\u4e00\u4efd\uff09\uff0c\u4f46\u4f60\u56de\u7b54\u65f6\u8bf4\u7684\u662f<strong>\u4f60\u81ea\u5df1\u7684<\/strong>\u540d\u5b57\u3002self \u5c31\u662f\u65b9\u6cd5\u6267\u884c\u65f6\u300c\u8c01\u5728\u8bf4\u8bdd\u300d\u7684\u90a3\u4e2a\u300c\u8c01\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>dog.bark() \u4e0e Dog.bark(dog) \u7b49\u4ef7\uff1b\u4e0d\u540c\u5bf9\u8c61\u8c03\u7528\uff0cself \u5404\u6307\u5404\u7684<\/strong>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>class Dog:\n    def __init__(self, name):\n        self.name = name\n\n    def bark(self):\n        print(f\"{self.name}\uff1a\u6c6a\u6c6a\uff01\")\n\n    def introduce(self):\n        print(\"\u6211\u662f\", self.name)\n\na = Dog(\"\u65fa\u8d22\")\nb = Dog(\"\u6765\u798f\")\na.bark()            # \u8bed\u6cd5\u7cd6\u5199\u6cd5\uff1a\u81ea\u52a8\u628a a \u4f20\u7ed9 self\nDog.bark(b)         # \u672c\u8d28\u5199\u6cd5\uff1a\u624b\u52a8\u628a b \u4f20\u7ed9 self\na.introduce()\nb.introduce()\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>\u65fa\u8d22\uff1a\u6c6a\u6c6a\uff01\n\u6765\u798f\uff1a\u6c6a\u6c6a\uff01\n\u6211\u662f \u65fa\u8d22\n\u6211\u662f \u6765\u798f\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u524d\u4e24\u884c\u8f93\u51fa\u4e00\u6a21\u4e00\u6837\uff0c\u8bc1\u660e <code>dog.bark()<\/code> \u4e0e <code>Dog.bark(dog)<\/code> \u5b8c\u5168\u7b49\u4ef7\u2014\u2014\u65b9\u6cd5\u5b9a\u4e49\u65f6<strong>\u5fc5\u987b<\/strong>\u5199 self\u3001\u8c03\u7528\u65f6<strong>\u7edd\u4e0d<\/strong>\u5199 self\u3002<code>introduce<\/code> \u65b9\u6cd5\u53ea\u6709\u4e00\u4efd\uff0c\u4f46 <code>a.introduce()<\/code> \u65f6 self \u662f a\u3001<code>b.introduce()<\/code> \u65f6 self \u662f b\u2014\u2014\u65b9\u6cd5\u4ee3\u7801\u5171\u4eab\uff0c\u5c5e\u6027\u5404\u5f52\u5404\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\u65b9\u6cd5\u5b9a\u4e49\u5fd8\u4e86 self\uff1a<code>def bark():<\/code> \u2192 \u95ee\u9898\uff1a\u8c03\u7528\u65f6\u62a5 <code>TypeError: bark() takes 0 positional arguments but 1 was given<\/code> \u2192 \u6b63\u786e\u5199\u6cd5\uff1a\u5b9e\u4f8b\u65b9\u6cd5\u7b2c\u4e00\u4e2a\u53c2\u6570\u5fc5\u987b\u662f <code>self<\/code>\u3002<\/li>\n\n\n\n<li>\u9519\u8bef\u5199\u6cd5\uff1a\u8c03\u7528\u65f6\u624b\u52a8\u4f20 self\uff1a<code>dog.bark(dog)<\/code> \u2192 \u95ee\u9898\uff1a\u62a5\u53c2\u6570\u4e2a\u6570\u9519\u8bef\uff08self \u5df2\u81ea\u52a8\u4f20\u5165\uff09 \u2192 \u6b63\u786e\u5199\u6cd5\uff1a\u8c03\u7528\u65f6<strong>\u4e0d\u8981<\/strong>\u4f20 self\u3002<\/li>\n\n\n\n<li>\u9519\u8bef\u5199\u6cd5\uff1a\u5728\u65b9\u6cd5\u91cc\u7528\u5168\u5c40\u53d8\u91cf\u5b58\u6570\u636e \u2192 \u95ee\u9898\uff1a\u591a\u4e2a\u5bf9\u8c61\u5171\u4eab\u4e00\u4efd\u6570\u636e\uff0c\u4e92\u76f8\u4e32\u5473 \u2192 \u6b63\u786e\u5199\u6cd5\uff1a\u4e00\u5f8b <code>self.xxx<\/code> \u5b58\u5230\u5bf9\u8c61\u81ea\u5df1\u8eab\u4e0a\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u8bb0\u5fc6\u53e3\u8bc0<\/strong>\uff1a\u65b9\u6cd5\u5b9a\u4e49\u6709 self\uff0c\u8c03\u7528\u65f6\u5019\u81ea\u52a8\u4f20\uff1bself \u5c31\u662f\u6211\u81ea\u5df1\uff0c\u5c5e\u6027\u90fd\u5f80\u8eab\u4e0a\u6302\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">4 <strong>str<\/strong> \u80cc\u540e\u7684\u8c03\u7528\u94fe \u2014\u2014 \u6253\u5370\u4e00\u4e2a\u5bf9\u8c61\u65f6\u53d1\u751f\u4e86\u4ec0\u4e48<\/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>__str__<\/code> \u662f\u300c\u8f6c\u5b57\u7b26\u4e32\u300d\u7684\u9b54\u6cd5\u65b9\u6cd5\uff08\u9b54\u6cd5\u65b9\u6cd5 = \u53cc\u4e0b\u5212\u7ebf\u5f00\u5934\u7ed3\u5c3e\u3001Python \u81ea\u52a8\u8c03\u7528\u7684\u7279\u6b8a\u65b9\u6cd5\uff0cDay 17 \u4f1a\u7cfb\u7edf\u5b66\uff09\u3002\u5b9a\u4e49\u5b83\u4e4b\u540e\uff0c<code>print(\u5bf9\u8c61)<\/code>\u3001<code>str(\u5bf9\u8c61)<\/code>\u3001f-string \u91cc <code>{\u5bf9\u8c61}<\/code> \u90fd\u4f1a\u663e\u793a\u6210\u4f60\u8bbe\u8ba1\u7684\u6587\u5b57\uff0c\u800c\u4e0d\u662f <code>0x...<\/code> \u5185\u5b58\u5730\u5740\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>print(obj)<\/code> \u7684\u6267\u884c\u94fe\uff1a<code>print<\/code> \u5185\u90e8\u8c03 <code>str(obj)<\/code> \u2192 <code>str(obj)<\/code> \u53bb <code>type(obj)<\/code>\uff08obj \u7684\u7c7b\uff09\u91cc\u627e <code>__str__<\/code> \u65b9\u6cd5 \u2192 \u8c03\u7528\u5b83\u62ff\u5230\u5b57\u7b26\u4e32\u518d\u8f93\u51fa\u3002\u5982\u679c\u7c7b\u91cc\u6ca1\u5b9a\u4e49 <code>__str__<\/code>\uff0c<code>str(obj)<\/code> \u4f1a\u9000\u800c\u6c42\u5176\u6b21\u7528 <code>__repr__<\/code>\uff08Day 17 \u8bb2\uff09\uff0c\u518d\u6ca1\u6709\u5c31\u7528\u57fa\u7c7b\u9ed8\u8ba4\u7684\u5730\u5740\u683c\u5f0f <code>&lt;__main__.Dog object at 0x...&gt;<\/code>\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\">\u8eab\u4efd\u8bc1\u53f7\u80fd\u552f\u4e00\u6807\u8bc6\u4e00\u4e2a\u4eba\uff0c\u4f46\u6ca1\u4eba\u7528\u8eab\u4efd\u8bc1\u53f7\u4ecb\u7ecd\u81ea\u5df1\u3002<code>__str__<\/code> \u5c31\u662f<strong>\u5bf9\u8c61\u7684\u540d\u7247<\/strong>\uff1a\u9ed8\u8ba4\u7684\u5730\u5740\u683c\u5f0f\u50cf\u4e00\u4e32\u7f16\u53f7\uff0c\u5b9a\u4e49 <code>__str__<\/code> \u540e\uff0c\u5bf9\u8c61\u5728\u300c\u81ea\u6211\u4ecb\u7ecd\u300d\u65f6\u4eae\u51fa\u7cbe\u5fc3\u8bbe\u8ba1\u7684\u540d\u7247\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>\u6ca1\u6709 <strong>str<\/strong> \u65f6\uff0c\u6253\u5370\u5bf9\u8c61\u770b\u5230\u7684\u662f\u5730\u5740<\/strong>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>class Dog:\n    def __init__(self, name):\n        self.name = name\n\ndog = Dog(\"\u65fa\u8d22\")\nprint(dog)\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u793a\u4f8b\u8f93\u51fa\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>&lt;__main__.Dog object at 0x0000020B12345678&gt;\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u6ca1\u6709\u5b9a\u4e49 <code>__str__<\/code> \u65f6\uff0c<code>print(dog)<\/code> \u663e\u793a\u7c7b\u540d + \u5185\u5b58\u5730\u5740\u2014\u2014\u5bf9\u8c03\u8bd5\u6beb\u65e0\u5e2e\u52a9\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">2 <strong>\u5b9a\u4e49 <strong>str<\/strong> \u540e\uff0c\u6253\u5370\u53d8\u5f97\u53ef\u8bfb<\/strong>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>class Dog:\n    def __init__(self, name):\n        self.name = name\n\n    def __str__(self):\n        return f\"\u5c0f\u72d7{self.name}\"\n\ndog = Dog(\"\u65fa\u8d22\")\nprint(dog)          # print \u81ea\u52a8\u8c03\u7528 __str__\nprint(str(dog))     # str() \u4e5f\u8c03\u7528 __str__\nprint(f\"\u8fd9\u662f{dog}\")  # f-string \u91cc\u7684 {dog} \u540c\u6837\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>\u5c0f\u72d7\u65fa\u8d22\n\u5c0f\u72d7\u65fa\u8d22\n\u8fd9\u662f\u5c0f\u72d7\u65fa\u8d22\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><code>__str__<\/code> \u65b9\u6cd5\u4f53\u91cc\u7528 <code>return<\/code> \u8fd4\u56de\u4e00\u4e2a\u5b57\u7b26\u4e32\uff08\u6ce8\u610f\u662f return \u4e0d\u662f print\uff01\uff09\u3002\u53ea\u8981\u8fd4\u56de\u4e86\u5b57\u7b26\u4e32\uff0c<code>print<\/code>\u3001<code>str()<\/code>\u3001f-string \u4e09\u79cd\u573a\u666f\u90fd\u4f1a\u81ea\u52a8\u5c55\u793a\u5b83\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>__str__<\/code> \u91cc\u5199 <code>print(...)<\/code> \u4e0d return \u2192 \u95ee\u9898\uff1a\u6253\u5370\u65f6\u8f93\u51fa None \u6216\u9519\u4e71 \u2192 \u6b63\u786e\u5199\u6cd5\uff1a<code>__str__<\/code> \u5fc5\u987b <code>return<\/code> \u4e00\u4e2a\u5b57\u7b26\u4e32\u3002<\/li>\n\n\n\n<li>\u9519\u8bef\u5199\u6cd5\uff1a<code>__str__<\/code> \u91cc\u5199 <code>print(self)<\/code> \u2192 \u95ee\u9898\uff1a\u53c8\u89e6\u53d1 <code>__str__<\/code>\uff0c\u65e0\u9650\u9012\u5f52\uff0c\u62a5 <code>RecursionError<\/code> \u2192 \u6b63\u786e\u5199\u6cd5\uff1a\u5728 <code>__str__<\/code> \u91cc\u53ea\u8bbf\u95ee <code>self.\u5c5e\u6027<\/code>\u3002<\/li>\n\n\n\n<li>\u9519\u8bef\u5199\u6cd5\uff1a<code>__str__<\/code> \u8fd4\u56de\u6570\u5b57\uff1a<code>return self.age<\/code> \u2192 \u95ee\u9898\uff1a\u62a5 <code>TypeError: __str__ returned non-string<\/code> \u2192 \u6b63\u786e\u5199\u6cd5\uff1a\u5148\u8f6c\u5b57\u7b26\u4e32\uff1a<code>return str(self.age)<\/code>\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u8bb0\u5fc6\u53e3\u8bc0<\/strong>\uff1aprint \u627e str\uff0cstr \u627e\u65b9\u6cd5\uff0creturn \u5b57\u7b26\u4e32\u624d\u7b97\u6570\uff1b\u4e0d\u5b9a\u4e49\u5c31\u4eae\u5730\u5740\uff0c\u5b9a\u4e49\u4e86\u5c31\u4eae\u540d\u7247\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">5 \u7c7b\u5c5e\u6027 vs \u5b9e\u4f8b\u5c5e\u6027 \u2014\u2014 \u5927\u5bb6\u5171\u4eab\u7684 vs \u81ea\u5df1\u72ec\u6709\u7684<\/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\">\u5199\u5728\u7c7b\u4f53\u91cc\uff08\u65b9\u6cd5\u5916\uff09\u7684\u53d8\u91cf\u53eb<strong>\u7c7b\u5c5e\u6027<\/strong>\uff0c\u6240\u6709\u5bf9\u8c61\u5171\u4eab\u4e00\u4efd\uff1b\u5728 <code>__init__<\/code> \u91cc\u7528 <code>self.xxx<\/code> \u521b\u5efa\u7684\u662f<strong>\u5b9e\u4f8b\u5c5e\u6027<\/strong>\uff0c\u6bcf\u4e2a\u5bf9\u8c61\u81ea\u5df1\u72ec\u6709\u4e00\u4efd\u3002\u533a\u5206\u5b83\u4eec\u80fd\u89e3\u51b3\u4e24\u4e2a\u5b9e\u9645\u95ee\u9898\uff1a\u2460 \u8ba9\u5168\u4f53\u5bf9\u8c61\u5171\u4eab\u914d\u7f6e \/ \u8ba1\u6570\u5668\uff1b\u2461 \u907f\u514d\u300c\u660e\u660e\u60f3\u72ec\u6709\uff0c\u7ed3\u679c\u53d8\u6210\u5171\u4eab\u300d\u7684\u8be1\u5f02 bug\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\u5c5e\u6027\u5b58\u5728<strong>\u7c7b\u7684<\/strong> <code>__dict__<\/code> \u91cc\uff0c\u5b9e\u4f8b\u5c5e\u6027\u5b58\u5728<strong>\u5bf9\u8c61\u7684<\/strong> <code>__dict__<\/code> \u91cc\u3002\u8bbf\u95ee <code>obj.attr<\/code> \u5148\u67e5\u5b9e\u4f8b\u5b57\u5178\uff0c\u67e5\u4e0d\u5230\u518d\u67e5\u7c7b\u5b57\u5178\u2014\u2014\u6240\u4ee5\u5b9e\u4f8b\u5c5e\u6027\u4f1a\u300c\u906e\u4f4f\u300d\u540c\u540d\u7c7b\u5c5e\u6027\u3002\u53cd\u8fc7\u6765\uff0c<strong>\u7ed9\u5b9e\u4f8b\u8d4b\u503c\u4e0d\u4f1a\u5f71\u54cd\u7c7b\u5c5e\u6027<\/strong>\uff08\u5b9e\u4f8b\u91cc\u90a3\u4efd\u662f\u81ea\u5df1\u65b0\u5efa\u7684\uff09\u3002\u8fd9\u4e2a\u300c\u906e\u853d\u300d\u89c4\u5219\u662f\u7406\u89e3\u5171\u4eab\u4e0e\u72ec\u6709\u5173\u952e\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\">\u7c7b\u5c5e\u6027\u50cf<strong>\u516c\u53f8\u98df\u5802<\/strong>\uff1a\u6240\u6709\u5458\u5de5\u90fd\u80fd\u5403\u540c\u4e00\u9505\u996d\uff1b\u5b9e\u4f8b\u5c5e\u6027\u50cf<strong>\u4e2a\u4eba\u996d\u76d2<\/strong>\uff1a\u6bcf\u4e2a\u4eba\u996d\u76d2\u91cc\u7684\u83dc\u662f\u81ea\u5df1\u7684\u3002\u4f60\u5728\u81ea\u5df1\u996d\u76d2\u91cc\u52a0\u4e86\u9e21\u817f\uff08\u7ed9\u5b9e\u4f8b\u5c5e\u6027\u8d4b\u503c\uff09\uff0c\u98df\u5802\u7684\u9505\u5e76\u4e0d\u4f1a\u591a\u4e00\u4e2a\u9e21\u817f\uff08\u7c7b\u5c5e\u6027\u4e0d\u53d8\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>\u7c7b\u5c5e\u6027\u5168\u4f53\u5171\u4eab<\/strong>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>class Dog:\n    species = \"\u72ac\u79d1\"     # \u7c7b\u5c5e\u6027\uff1a\u6240\u6709\u72d7\u5171\u4eab\n\na = Dog()\nb = Dog()\nprint(a.species, b.species, Dog.species)\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>\u72ac\u79d1 \u72ac\u79d1 \u72ac\u79d1\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u7c7b\u5c5e\u6027\u5b9a\u4e49\u5728\u7c7b\u4f53\u6700\u5916\u5c42\uff08\u7f29\u8fdb\u4e00\u7ea7\u3001\u4e0e\u65b9\u6cd5\u540c\u7ea7\uff09\u3002\u4e09\u5904\u6253\u5370\u540c\u4e00\u4e2a\u503c\uff0c\u56e0\u4e3a\u5b83\u53ea\u6709\u4e00\u4efd\uff0c\u5b58\u5728\u7c7b\u7684\u5b57\u5178\u91cc\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">2 <strong>\u7ed9\u5b9e\u4f8b\u8d4b\u503c = \u5728\u81ea\u5df1\u7684\u5b57\u5178\u91cc\u65b0\u5efa\uff0c\u4e0d\u78b0\u7c7b\u5c5e\u6027<\/strong>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>class Dog:\n    species = \"\u72ac\u79d1\"\n\na = Dog()\na.species = \"\u54c8\u58eb\u5947\"   # \u5728 a \u81ea\u5df1\u7684\u5b57\u5178\u91cc\u65b0\u5efa species\nprint(a.species)      # \u81ea\u5df1\u7684\u90a3\u4efd\nprint(Dog.species)    # \u7c7b\u91cc\u90a3\u4efd\u539f\u5c01\u4e0d\u52a8\nprint(a.__dict__)     # \u770b\u770b a \u7684\u5b57\u5178\u91cc\u6709\u4ec0\u4e48\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>\u54c8\u58eb\u5947\n\u72ac\u79d1\n{'species': '\u54c8\u58eb\u5947'}\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">a \u7684 <code>__dict__<\/code> \u91cc\u591a\u4e86\u81ea\u5df1\u7684 <code>species<\/code>\uff0c\u4ece\u6b64 a \u8bbf\u95ee\u65f6\u300c\u5148\u67e5\u81ea\u5df1\u300d\u547d\u4e2d\uff0c\u4e0d\u518d\u770b\u7c7b\u7684\u3002\u8fd9\u5c31\u662f\u300c\u906e\u853d\u300d\uff1a<strong>\u81ea\u5df1\u6709\u4e86\u5c31\u4e0d\u770b\u516c\u5171\u7684<\/strong>\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">3 <strong>\u7528\u7c7b\u5c5e\u6027\u5b9e\u73b0\u300c\u81ea\u52a8\u9012\u589e\u7684\u8d26\u53f7\u7f16\u53f7\u300d<\/strong>\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>class Account:\n    _next_no = 1001              # \u7c7b\u5c5e\u6027\uff1a\u4e0b\u4e00\u4e2a\u53ef\u7528\u7684\u8d26\u53f7\uff08_ \u5f00\u5934\u8868\u793a\"\u5185\u90e8\u4f7f\u7528\"\uff09\n\n    def __init__(self, owner):\n        self.owner = owner\n        self.account_no = Account._next_no   # \u628a\u5f53\u524d\u7f16\u53f7\u62ff\u7ed9\u81ea\u5df1\n        Account._next_no += 1                # \u5168\u5c40\u8ba1\u6570\u5668 +1\uff0c\u4f9b\u4e0b\u4e00\u4e2a\u5bf9\u8c61\u7528\n\na1 = Account(\"\u5f20\u4e09\")\na2 = Account(\"\u674e\u56db\")\na3 = Account(\"\u738b\u4e94\")\nprint(a1.account_no, a2.account_no, a3.account_no)\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>1001 1002 1003\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><code>_next_no<\/code> \u662f\u7c7b\u5c5e\u6027\uff0c\u6240\u6709\u5bf9\u8c61\u5171\u4eab\u8fd9\u4e00\u4e2a\u8ba1\u6570\u5668\u3002\u6ce8\u610f\u64cd\u4f5c\u7c7b\u5c5e\u6027\u7528\u7684\u662f <code>Account._next_no<\/code>\uff08\u901a\u8fc7\u7c7b\u540d\uff09\uff0c<strong>\u4e0d\u662f<\/strong> <code>self._next_no += 1<\/code>\uff08\u90a3\u4f1a\u5728\u81ea\u5df1\u8eab\u4e0a\u65b0\u5efa\u4e00\u4efd\uff0c\u8ba1\u6570\u5668\u6c38\u8fdc\u4e0d\u52a8\uff09\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\u5728\u65b9\u6cd5\u91cc <code>self.count += 1<\/code> \u60f3\u6539\u7c7b\u5c5e\u6027 \u2192 \u95ee\u9898\uff1a\u5b9e\u9645\u662f\u5728\u81ea\u5df1\u8eab\u4e0a\u65b0\u5efa\u5b9e\u4f8b\u5c5e\u6027\uff0c\u7c7b\u5c5e\u6027\u7eb9\u4e1d\u4e0d\u52a8 \u2192 \u6b63\u786e\u5199\u6cd5\uff1a\u901a\u8fc7\u7c7b\u540d\u6539\uff1a<code>MyClass.count += 1<\/code>\u3002<\/li>\n\n\n\n<li>\u9519\u8bef\u5199\u6cd5\uff1a\u7c7b\u5c5e\u6027\u662f\u5217\u8868\uff0c\u4e00\u4e2a\u5bf9\u8c61\u5f80\u91cc append \u2192 \u95ee\u9898\uff1a\u6240\u6709\u5bf9\u8c61\u5171\u4eab\u540c\u4e00\u4e2a\u5217\u8868\uff0c\u6570\u636e\u4e92\u76f8\u6c61\u67d3 \u2192 \u6b63\u786e\u5199\u6cd5\uff1a\u53ef\u53d8\u6570\u636e\u653e <code>__init__<\/code> \u91cc\uff1a<code>self.items = []<\/code>\u3002<\/li>\n\n\n\n<li>\u9519\u8bef\u5199\u6cd5\uff1a\u628a\u7c7b\u5c5e\u6027\u5f53\u300c\u6bcf\u4e2a\u5bf9\u8c61\u90fd\u6709\u300d\u7528 \u2192 \u95ee\u9898\uff1a\u4e00\u4e2a\u5bf9\u8c61\u6539\u4e86\uff0c\u5176\u4ed6\u5bf9\u8c61\u5168\u53d8 \u2192 \u6b63\u786e\u5199\u6cd5\uff1a\u60f3\u5404\u7ba1\u5404\u7684\uff0c\u7528\u5b9e\u4f8b\u5c5e\u6027\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u8bb0\u5fc6\u53e3\u8bc0<\/strong>\uff1a\u7c7b\u5c5e\u6027\u5171\u4eab\u4e00\u4efd\uff0c\u5b9e\u4f8b\u5c5e\u6027\u5404\u81ea\u6709\uff1b\u5148\u67e5\u81ea\u5df1\u518d\u67e5\u7c7b\uff0c\u6539\u7c7b\u8981\u7528\u7c7b\u540d\u6539\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">6 \u52a8\u624b\u5b9e\u8df5\uff1a\u94f6\u884c\u8d26\u6237\u7c7b<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u505a\u4e00\u4e2a <code>BankAccount<\/code> \u7c7b\uff0c\u652f\u6301\u5f00\u6237\uff08\u59d3\u540d+\u521d\u59cb\u4f59\u989d\uff09\u3001\u5b58\u6b3e\u3001\u53d6\u6b3e\u3001\u67e5\u8be2\u4f59\u989d\uff0c\u53d6\u6b3e\u4e0d\u80fd\u900f\u652f\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code># bank_account.py \u2014\u2014 \u94f6\u884c\u8d26\u6237\u7c7b\nclass BankAccount:\n    def __init__(self, owner, balance=0):\n        self.owner = owner        # \u6237\u4e3b\u59d3\u540d\n        self.balance = balance    # \u5f53\u524d\u4f59\u989d\n\n    def deposit(self, amount):\n        if amount &lt;= 0:\n            print(\"\u5b58\u6b3e\u91d1\u989d\u5fc5\u987b\u5927\u4e8e 0\")\n            return\n        self.balance += amount\n        print(f\"\u5b58\u5165 {amount} \u5143\uff0c\u4f59\u989d {self.balance} \u5143\")\n\n    def withdraw(self, amount):\n        if amount &lt;= 0:\n            print(\"\u53d6\u6b3e\u91d1\u989d\u5fc5\u987b\u5927\u4e8e 0\")\n            return\n        if amount &gt; self.balance:\n            print(\"\u4f59\u989d\u4e0d\u8db3\uff0c\u53d6\u6b3e\u5931\u8d25\")\n            return\n        self.balance -= amount\n        print(f\"\u53d6\u51fa {amount} \u5143\uff0c\u4f59\u989d {self.balance} \u5143\")\n\n    def show(self):\n        print(f\"\u6237\u4e3b\uff1a{self.owner}\uff0c\u4f59\u989d\uff1a{self.balance} \u5143\")\n\n    def __str__(self):\n        return f\"\u94f6\u884c\u8d26\u6237&#91;{self.owner}] \u4f59\u989d {self.balance} \u5143\"\n\nacc = BankAccount(\"\u5f20\u4e09\", 1000)\nprint(acc)\nacc.deposit(500)\nacc.withdraw(200)\nacc.withdraw(99999)\nacc.show()\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>\u94f6\u884c\u8d26\u6237&#91;\u5f20\u4e09] \u4f59\u989d 1000 \u5143\n\u5b58\u5165 500 \u5143\uff0c\u4f59\u989d 1500 \u5143\n\u53d6\u51fa 200 \u5143\uff0c\u4f59\u989d 1300 \u5143\n\u4f59\u989d\u4e0d\u8db3\uff0c\u53d6\u6b3e\u5931\u8d25\n\u6237\u4e3b\uff1a\u5f20\u4e09\uff0c\u4f59\u989d\uff1a1300 \u5143\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u5347\u7ea7\u6311\u6218<\/strong>\uff1a\u7ed9\u8d26\u6237\u52a0\u4e00\u4e2a <code>transfer<\/code> \u8f6c\u8d26\u65b9\u6cd5\uff08\u4ece\u5f53\u524d\u8d26\u6237\u8f6c\u5230\u53e6\u4e00\u4e2a\u8d26\u6237\uff09\uff0c\u5e76\u7ed9\u6bcf\u4e2a\u8d26\u6237\u52a0\u4e00\u4e2a\u81ea\u52a8\u9012\u589e\u7684\u8d26\u53f7 <code>account_no<\/code>\uff08\u63d0\u793a\uff1a\u53ef\u4ee5\u7528\u7c7b\u5c5e\u6027 <code>_next_no<\/code> \u5b9e\u73b0\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\">\u7c7b\u7684\u672c\u8d28\uff1a\u6a21\u677f\uff08\u6a21\u5177\uff09\uff0c\u52a0\u62ec\u53f7 <code>Dog()<\/code> \u624d\u9020\u51fa\u5bf9\u8c61\uff1b\u5bf9\u8c61 = \u5c5e\u6027\uff08\u6570\u636e\uff09+ \u65b9\u6cd5\uff08\u884c\u4e3a\uff09\n\u5bf9\u8c61\u5e95\u5c42\u662f\u5c5e\u6027\u5b57\u5178 <code>__dict__<\/code>\uff1b\u8bbf\u95ee <code>obj.attr<\/code> \u5148\u67e5\u5b9e\u4f8b\u5b57\u5178\u3001\u518d\u67e5\u7c7b\u5b57\u5178\n<code>__init__<\/code> \u5728\u521b\u5efa\u5bf9\u8c61\u65f6\u81ea\u52a8\u6267\u884c\uff0c\u8d1f\u8d23\u521d\u59cb\u5316\u5c5e\u6027\uff1b<code>__new__<\/code> \u8d1f\u8d23\u5206\u914d\u5185\u5b58\uff0c<code>__init__<\/code> \u4e0d\u80fd\u8fd4\u56de\u975e None\n<code>self<\/code> \u662f\u300c\u8c03\u7528\u65b9\u6cd5\u7684\u90a3\u4e2a\u5bf9\u8c61\u300d\uff1b<code>dog.bark()<\/code> \u7b49\u4ef7\u4e8e <code>Dog.bark(dog)<\/code>\uff0c\u5b9a\u4e49\u5199 self\u3001\u8c03\u7528\u4e0d\u5199 self\n<code>print<\/code> \/ <code>str()<\/code> \/ f-string \u90fd\u4f1a\u81ea\u52a8\u8c03\u7528 <code>__str__<\/code>\uff0c\u6ca1\u5b9a\u4e49\u65f6\u663e\u793a\u5185\u5b58\u5730\u5740\n\u7c7b\u5c5e\u6027\u5168\u4f53\u5171\u4eab\u4e00\u4efd\uff08\u5b58\u7c7b\u7684\u5b57\u5178\uff09\uff0c\u5b9e\u4f8b\u5c5e\u6027\u5404\u5b58\u5404\u7684\uff1b\u5b9e\u4f8b\u5c5e\u6027\u4f1a\u906e\u853d\u7c7b\u5c5e\u6027\uff0c\u6539\u7c7b\u5c5e\u6027\u8981\u7528\u7c7b\u540d\u6539\n\u94f6\u884c\u8d26\u6237\u7c7b\u53ef\u6b63\u5e38\u5f00\u6237\u3001\u5b58\u6b3e\u3001\u53d6\u6b3e\u4e14\u4e0d\u80fd\u900f\u652f<\/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>\u521b\u5efa\u5bf9\u8c61\u65f6\u5c11\u4f20\u4e86\u53c2\u6570<\/td><td>\u68c0\u67e5 <code>__init__<\/code> \u7684\u53c2\u6570\u5217\u8868\uff0c\u521b\u5efa\u65f6\u5168\u90e8\u4f20\u4e0a<\/td><\/tr><tr><td><code>AttributeError: 'Dog' object has no attribute 'name'<\/code><\/td><td>\u5fd8\u4e86\u5728 <code>__init__<\/code> \u91cc <code>self.name = ...<\/code>\uff0c\u6216\u62fc\u5199\u4e0d\u4e00\u81f4<\/td><td>\u5728 <code>__init__<\/code> \u4e2d\u521d\u59cb\u5316\u6240\u6709\u5c5e\u6027<\/td><\/tr><tr><td><code>TypeError: bark() takes 1 positional argument but 2 were given<\/code><\/td><td>\u5b9a\u4e49\u65b9\u6cd5\u5fd8\u4e86\u5199 <code>self<\/code><\/td><td>\u65b9\u6cd5\u7b2c\u4e00\u4e2a\u53c2\u6570\u5fc5\u987b\u662f <code>self<\/code><\/td><\/tr><tr><td><code>NameError: name 'self' is not defined<\/code><\/td><td>\u5728\u65b9\u6cd5\u91cc\u76f4\u63a5\u5199\u4e86 <code>self<\/code> \u5374\u6ca1\u628a\u5b83\u5f53\u53c2\u6570<\/td><td>\u786e\u8ba4 <code>self<\/code> \u5199\u5728\u53c2\u6570\u5217\u8868\u7b2c\u4e00\u4e2a<\/td><\/tr><tr><td>\u5bf9\u8c61\u5c5e\u6027\u4e92\u76f8\u4e32\u4e86<\/td><td>\u7528\u4e86\u5168\u5c40\u53d8\u91cf\u5b58\u6570\u636e\uff0c\u800c\u4e0d\u662f\u5b9e\u4f8b\u5c5e\u6027 <code>self.xxx<\/code><\/td><td>\u6240\u6709\u5bf9\u8c61\u6570\u636e\u4e00\u5f8b\u5b58\u6210 <code>self.\u5c5e\u6027<\/code><\/td><\/tr><\/tbody><\/table><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>1 \u7c7b\u4e0e\u5bf9\u8c61 \u2014\u2014 \u300c\u6570\u636e + \u884c\u4e3a\u300d\u662f\u600e\u4e48\u7ed1\u5728\u4e00\u8d77\u7684 \u662f\u4ec0\u4e48\uff1f\u4e3a\u4ec0\u4e48\u5b66\uff1f \u7c7b\uff08class\uff09\u662f\u6a21\u677f\uff0c\u5bf9\u8c61\uff08ob [&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-96","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\/96","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=96"}],"version-history":[{"count":2,"href":"https:\/\/ltrainyard.icu\/index.php\/wp-json\/wp\/v2\/posts\/96\/revisions"}],"predecessor-version":[{"id":144,"href":"https:\/\/ltrainyard.icu\/index.php\/wp-json\/wp\/v2\/posts\/96\/revisions\/144"}],"wp:attachment":[{"href":"https:\/\/ltrainyard.icu\/index.php\/wp-json\/wp\/v2\/media?parent=96"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ltrainyard.icu\/index.php\/wp-json\/wp\/v2\/categories?post=96"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ltrainyard.icu\/index.php\/wp-json\/wp\/v2\/tags?post=96"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}