{"id":205143,"date":"2025-05-29T08:05:43","date_gmt":"2025-05-29T00:05:43","guid":{"rendered":"https:\/\/server.hk\/cnblog\/205143\/"},"modified":"2025-05-29T08:05:43","modified_gmt":"2025-05-29T00:05:43","slug":"python-%e5%af%b9%e8%b1%a1%e5%ae%9e%e4%be%8b%e5%8c%96%e9%87%8d%e5%a4%8d%e8%a7%a6%e5%8f%91__del__%e6%96%b9%e6%b3%95%e5%af%bc%e8%87%b4%e5%bc%82%e5%b8%b8%ef%bc%9a%e5%a6%82%e4%bd%95%e9%81%bf%e5%85%8d","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/205143\/","title":{"rendered":"Python \u5bf9\u8c61\u5b9e\u4f8b\u5316\u91cd\u590d\u89e6\u53d1__del__\u65b9\u6cd5\u5bfc\u81f4\u5f02\u5e38\uff1a\u5982\u4f55\u907f\u514d\uff1f"},"content":{"rendered":"<p><b><\/b>     <\/p>\n<h1>Python \u5bf9\u8c61\u5b9e\u4f8b\u5316\u91cd\u590d\u89e6\u53d1__del__\u65b9\u6cd5\u5bfc\u81f4\u5f02\u5e38\uff1a\u5982\u4f55\u907f\u514d\uff1f<\/h1>\n<p>\u4ece\u73b0\u5728\u5f00\u59cb\uff0c\u6211\u4eec\u8981\u52aa\u529b\u5b66\u4e60\u5566\uff01\u4eca\u5929\u6211\u7ed9\u5927\u5bb6\u5e26\u6765\uff0c\u611f\u5174\u8da3\u7684\u670b\u53cb\u8bf7\u7ee7\u7eed\u770b\u4e0b\u53bb\u5427\uff01\u4e0b\u6587\u4e2d\u7684\u5185\u5bb9\u6211\u4eec\u4e3b\u8981\u4f1a\u6d89\u53ca\u5230<span style=\"color: #FF6600;, Helvetica, Arial, sans-serif;font-size: 14px;background-color: #FFFFFF\"><\/span>\u7b49\u7b49\u77e5\u8bc6\u70b9\uff0c\u5982\u679c\u5728\u9605\u8bfb\u672c\u6587\u8fc7\u7a0b\u4e2d\u6709\u9047\u5230\u4e0d\u6e05\u695a\u7684\u5730\u65b9\uff0c\u6b22\u8fce\u7559\u8a00\u5440\uff01\u6211\u4eec\u4e00\u8d77\u8ba8\u8bba\uff0c\u4e00\u8d77\u5b66\u4e60\uff01<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.17golang.com\/uploads\/20241124\/17324411656742f44dc36ba.jpg\" class=\"aligncenter\"><\/p>\n<p><strong>\u95ee\u9898\u63cf\u8ff0\uff1a<\/strong><\/p>\n<p>\u5728 python \u4ee3\u7801\u4e2d\uff0c\u5b58\u5728\u91cd\u590d\u5b9e\u4f8b\u5316\u5bf9\u8c61\u5bfc\u81f4 <strong>del<\/strong> \u65b9\u6cd5\u89e6\u53d1\u7684\u5f02\u5e38\u95ee\u9898\u3002<\/p>\n<p><strong>\u95ee\u9898\u539f\u56e0\uff1a<\/strong><\/p>\n<p>\u5728 python \u4e2d\uff0c\u5f53\u4e00\u4e2a\u5bf9\u8c61\u4e0d\u518d\u88ab\u5f15\u7528\u65f6\uff0c\u5b83\u7684 <strong>del<\/strong> \u65b9\u6cd5\u4f1a\u88ab\u8c03\u7528\u6765\u91ca\u653e\u5176\u6301\u6709\u7684\u8d44\u6e90\u3002\u7136\u800c\uff0c\u5982\u679c\u5728 <strong>del<\/strong> \u65b9\u6cd5\u6267\u884c\u8fc7\u7a0b\u4e2d\u521b\u5efa\u4e86\u65b0\u7684\u5bf9\u8c61\uff0c\u53ef\u80fd\u4f1a\u5bfc\u81f4\u5faa\u73af\u5f15\u7528\uff0c\u4ece\u800c\u65e0\u6cd5\u91ca\u653e\u8d44\u6e90\u5e76\u5f15\u53d1\u5f02\u5e38\u3002<\/p>\n<p><strong>\u89e3\u51b3\u65b9\u6cd5\uff1a<\/strong><\/p>\n<p>\u4e3a\u4e86\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\uff0c\u9700\u8981\u907f\u514d\u5728 <strong>del<\/strong> \u65b9\u6cd5\u4e2d\u521b\u5efa\u65b0\u7684\u5bf9\u8c61\u3002\u53ef\u4ee5\u901a\u8fc7\u4ee5\u4e0b\u65b9\u5f0f\u89e3\u51b3\uff1a<\/p>\n<ul>\n<li>\u5728 <strong>del<\/strong> \u65b9\u6cd5\u4e2d\u6dfb\u52a0\u6761\u4ef6\u5224\u65ad\uff0c\u786e\u4fdd\u5728\u6267\u884c\u5220\u9664\u64cd\u4f5c\u4e4b\u524d\uff0c\u5bf9\u8c61\u6ca1\u6709\u88ab\u5176\u4ed6\u5bf9\u8c61\u5f15\u7528\u3002<\/li>\n<li>\u4f7f\u7528 context manager (with \u8bed\u53e5) \u6765\u7ba1\u7406\u5bf9\u8c61\u7684\u751f\u5b58\u5468\u671f\uff0c\u786e\u4fdd\u5728\u4f7f\u7528\u5b8c\u6bd5\u540e\u53ca\u65f6\u91ca\u653e\u8d44\u6e90\u3002<\/li>\n<li>\u5728\u4ee3\u7801\u4e2d\u663e\u5f0f\u5730\u91ca\u653e\u8d44\u6e90\uff0c\u800c\u4e0d\u662f\u4f9d\u8d56 <strong>del<\/strong> \u65b9\u6cd5\u3002<\/li>\n<\/ul>\n<p><strong>\u793a\u4f8b\u4ee3\u7801\uff1a<\/strong><\/p>\n<p>\u4ee5\u4e0b\u4ee3\u7801\u5c55\u793a\u4e86\u5982\u4f55\u901a\u8fc7\u6dfb\u52a0\u6761\u4ef6\u5224\u65ad\u6765\u89e3\u51b3\u95ee\u9898\uff1a<\/p>\n<pre>import pymysql\n\nclass Mydb(object):\n    def __init__(self, name):\n        self.name = name\n        self.conn = pymysql.connect(...)\n        self.cursor = self.conn.cursor()\n\n    def __del__(self):\n        if self.conn:\n            self.cursor.close()\n            self.conn.close()\n        print('\u9500\u6bc1\u8fde\u63a5', self.name)<\/pre>\n<p>\u5728\u8be5\u4ee3\u7801\u4e2d\uff0c__del__ \u65b9\u6cd5\u4f1a\u68c0\u67e5 self.conn \u662f\u5426\u5b58\u5728\uff0c\u53ea\u6709\u5f53\u8fde\u63a5\u5b58\u5728\u65f6\u624d\u6267\u884c\u5173\u95ed\u64cd\u4f5c\uff0c\u907f\u514d\u4e86\u5faa\u73af\u5f15\u7528\u3002<\/p>\n<p>\u672c\u7bc7\u5173\u4e8e\u300aPython \u5bf9\u8c61\u5b9e\u4f8b\u5316\u91cd\u590d\u89e6\u53d1__del__\u65b9\u6cd5\u5bfc\u81f4\u5f02\u5e38\uff1a\u5982\u4f55\u907f\u514d\uff1f\u300b\u7684\u4ecb\u7ecd\u5c31\u5230\u6b64\u7ed3\u675f\u5566\uff0c\u4f46\u662f\u5b66\u65e0\u6b62\u5883\uff0c\u60f3\u8981\u4e86\u89e3\u5b66\u4e60\u66f4\u591a\u5173\u4e8e\u6587\u7ae0\u7684\u76f8\u5173\u77e5\u8bc6\uff0c\u8bf7\u5173\u6ce8\u516c\u4f17\u53f7\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Python \u5bf9\u8c61\u5b9e\u4f8b\u5316\u91cd\u590d\u89e6\u53d1&#46;&#46;&#46;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4925],"tags":[],"class_list":["post-205143","post","type-post","status-publish","format-standard","hentry","category-4925"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/205143","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=205143"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/205143\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=205143"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=205143"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=205143"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}