{"id":2480,"date":"2017-07-20T10:57:11","date_gmt":"2017-07-20T02:57:11","guid":{"rendered":"http:\/\/cn.hostease.com\/xueyuan\/?p=2480"},"modified":"2025-01-08T16:29:18","modified_gmt":"2025-01-08T08:29:18","slug":"python%e8%bf%9b%e9%98%b609-%e5%8a%a8%e6%80%81%e7%b1%bb%e5%9e%8b","status":"publish","type":"post","link":"https:\/\/cn.hostease.com\/xueyuan\/jishu\/python\/python%e8%bf%9b%e9%98%b609-%e5%8a%a8%e6%80%81%e7%b1%bb%e5%9e%8b\/","title":{"rendered":"Python\u8fdb\u963609 \u52a8\u6001\u7c7b\u578b"},"content":{"rendered":"<div id=\"cnblogs_post_body\">\u52a8\u6001\u7c7b\u578b(dynamic typing)\u662fPython\u53e6\u4e00\u4e2a\u91cd\u8981\u7684\u6838\u5fc3\u6982\u5ff5\u3002\u6211\u4eec\u4e4b\u524d\u8bf4\u8fc7\uff0cPython\u7684\u53d8\u91cf(variable)\u4e0d\u9700\u8981\u58f0\u660e\uff0c\u800c\u5728\u8d4b\u503c\u65f6\uff0c\u53d8\u91cf\u53ef\u4ee5\u91cd\u65b0\u8d4b\u503c\u4e3a\u4efb\u610f\u503c\u3002\u8fd9\u4e9b\u90fd\u4e0e\u52a8\u6001\u7c7b\u578b\u7684\u6982\u5ff5\u76f8\u5173\u3002<\/p>\n<h3>\u52a8\u6001\u7c7b\u578b<\/h3>\n<p>\u5728\u6211\u4eec\u63a5\u89e6\u7684\u5bf9\u8c61\u4e2d\uff0c\u6709\u4e00\u7c7b\u7279\u6b8a\u7684\u5bf9\u8c61\uff0c\u662f\u7528\u4e8e\u5b58\u50a8\u6570\u636e\u7684\u3002\u5e38\u89c1\u7684\u8be5\u7c7b\u5bf9\u8c61\u5305\u62ec\u5404\u79cd\u6570\u5b57\uff0c\u5b57\u7b26\u4e32\uff0c\u8868\uff0c\u8bcd\u5178\u3002\u5728C\u8bed\u8a00\u4e2d\uff0c\u6211\u4eec\u79f0\u8fd9\u6837\u4e00\u4e9b\u6570\u636e\u7ed3\u6784\u4e3a\u53d8\u91cf\u3002\u800c\u5728Python\u4e2d\uff0c\u8fd9\u4e9b\u662f\u5bf9\u8c61\u3002<\/p>\n<p>\u5bf9\u8c61\u662f\u50a8\u5b58\u5728\u5185\u5b58\u4e2d\u7684\u5b9e\u4f53\u3002\u4f46\u6211\u4eec\u5e76\u4e0d\u80fd\u76f4\u63a5\u63a5\u89e6\u5230\u8be5\u5bf9\u8c61\u3002\u6211\u4eec\u5728\u7a0b\u5e8f\u4e2d\u5199\u7684\u5bf9\u8c61\u540d\uff0c\u53ea\u662f\u6307\u5411\u8fd9\u4e00\u5bf9\u8c61\u7684\u5f15\u7528(reference)\u3002<\/p>\n<p>\u5f15\u7528\u548c\u5bf9\u8c61\u5206\u79bb\uff0c\u662f\u52a8\u6001\u7c7b\u578b\u7684\u6838\u5fc3\u3002\u5f15\u7528\u53ef\u4ee5\u968f\u65f6\u6307\u5411\u4e00\u4e2a\u65b0\u7684\u5bf9\u8c61\uff1a<\/p>\n<div class=\"cnblogs_code\">\n<pre>a = 3\na = 'at'<\/pre>\n<\/div>\n<p>\u7b2c\u4e00\u4e2a\u8bed\u53e5\u4e2d\uff0c3\u662f\u50a8\u5b58\u5728\u5185\u5b58\u4e2d\u7684\u4e00\u4e2a\u6574\u6570\u5bf9\u8c61\u3002\u901a\u8fc7\u8d4b\u503c\uff0c\u5f15\u7528a\u6307\u5411\u5bf9\u8c613\u3002<\/p>\n<p>\u7b2c\u4e8c\u4e2a\u8bed\u53e5\u4e2d\uff0c\u5185\u5b58\u4e2d\u5efa\u7acb\u5bf9\u8c61\u2018at\u2019\uff0c\u662f\u4e00\u4e2a\u5b57\u7b26\u4e32(string)\u3002\u5f15\u7528a\u6307\u5411\u4e86&#8217;at&#8217;\u3002\u6b64\u65f6\uff0c\u5bf9\u8c613\u4e0d\u518d\u6709\u5f15\u7528\u6307\u5411\u5b83\u3002Python\u4f1a\u81ea\u52a8\u5c06\u6ca1\u6709\u5f15\u7528\u6307\u5411\u7684\u5bf9\u8c61\u9500\u6bc1(destruct)\uff0c\u91ca\u653e\u76f8\u5e94\u5185\u5b58\u3002<\/p>\n<p>(\u5bf9\u4e8e\u5c0f\u7684\u6574\u6570\u548c\u77ed\u5b57\u7b26\u4e32\uff0cPython\u4f1a\u7f13\u5b58\u8fd9\u4e9b\u5bf9\u8c61\uff0c\u800c\u4e0d\u662f\u9891\u7e41\u7684\u5efa\u7acb\u548c\u9500\u6bc1\u3002)<\/p>\n<div class=\"cnblogs_code\">\n<pre>a = 5\nb = a\na = a + 2<\/pre>\n<\/div>\n<p>\u518d\u770b\u8fd9\u4e2a\u4f8b\u5b50\u3002\u901a\u8fc7\u524d\u4e24\u4e2a\u53e5\u5b50\uff0c\u6211\u4eec\u8ba9a,b\u6307\u5411\u540c\u4e00\u4e2a\u6574\u6570\u5bf9\u8c615(b = a\u7684\u542b\u4e49\u662f\u8ba9\u5f15\u7528b\u6307\u5411\u5f15\u7528a\u6240\u6307\u7684\u90a3\u4e00\u4e2a\u5bf9\u8c61)\u3002\u4f46\u7b2c\u4e09\u4e2a\u53e5\u5b50\u5b9e\u9645\u4e0a\u5bf9\u5f15\u7528a\u91cd\u65b0\u8d4b\u503c\uff0c\u8ba9a\u6307\u5411\u4e00\u4e2a\u65b0\u7684\u5bf9\u8c617\u3002\u6b64\u65f6a,b\u5206\u522b\u6307\u5411\u4e0d\u540c\u7684\u5bf9\u8c61\u3002\u6211\u4eec\u770b\u5230\uff0c\u5373\u4f7f\u662f\u591a\u4e2a\u5f15\u7528\u6307\u5411\u540c\u4e00\u4e2a\u5bf9\u8c61\uff0c\u5982\u679c\u4e00\u4e2a\u5f15\u7528\u503c\u53d1\u751f\u53d8\u5316\uff0c\u90a3\u4e48\u5b9e\u9645\u4e0a\u662f\u8ba9\u8fd9\u4e2a\u5f15\u7528\u6307\u5411\u4e00\u4e2a\u65b0\u7684\u5f15\u7528\uff0c\u5e76\u4e0d\u5f71\u54cd\u5176\u4ed6\u7684\u5f15\u7528\u7684\u6307\u5411\u3002\u4ece\u6548\u679c\u4e0a\u770b\uff0c\u5c31\u662f\u5404\u4e2a\u5f15\u7528\u5404\u81ea\u72ec\u7acb\uff0c\u4e92\u4e0d\u5f71\u54cd\u3002<\/p>\n<p>\u5176\u5b83\u6570\u636e\u5bf9\u8c61\u4e5f\u662f\u5982\u6b64:<\/p>\n<div class=\"cnblogs_code\">\n<pre>L1 = [1,2,3]\nL2 = L1\nL1 = 1<\/pre>\n<\/div>\n<p>\u4f46\u6ce8\u610f\u4ee5\u4e0b\u60c5\u51b5<\/p>\n<div class=\"cnblogs_code\">\n<pre>L1 = [1,2,3]\nL2 = L1\nL1[0] = 10\nprint L2<\/pre>\n<\/div>\n<p>\u5728\u8be5\u60c5\u51b5\u4e0b\uff0c\u6211\u4eec\u4e0d\u518d\u5bf9L1\u8fd9\u4e00\u5f15\u7528\u8d4b\u503c\uff0c\u800c\u662f\u5bf9L1\u6240\u6307\u5411\u7684\u8868\u7684\u5143\u7d20\u8d4b\u503c\u3002\u7ed3\u679c\u662f\uff0cL2\u4e5f\u540c\u65f6\u53d1\u751f\u53d8\u5316\u3002<\/p>\n<p>\u539f\u56e0\u4f55\u5728\u5462\uff1f\u56e0\u4e3aL1\uff0cL2\u7684\u6307\u5411\u6ca1\u6709\u53d1\u751f\u53d8\u5316\uff0c\u4f9d\u7136\u6307\u5411\u90a3\u4e2a\u8868\u3002\u8868\u5b9e\u9645\u4e0a\u662f\u5305\u542b\u4e86\u591a\u4e2a\u5f15\u7528\u7684\u5bf9\u8c61\uff08\u6bcf\u4e2a\u5f15\u7528\u662f\u4e00\u4e2a\u5143\u7d20\uff0c\u6bd4\u5982L1[0]\uff0cL1[1]&#8230;, \u6bcf\u4e2a\u5f15\u7528\u6307\u5411\u4e00\u4e2a\u5bf9\u8c61\uff0c\u6bd4\u59821,2,3), \u3002\u800cL1[0] = 10\u8fd9\u4e00\u8d4b\u503c\u64cd\u4f5c\uff0c\u5e76\u4e0d\u662f\u6539\u53d8L1\u7684\u6307\u5411\uff0c\u800c\u662f\u5bf9L1[0], \u4e5f\u5c31\u662f\u8868\u5bf9\u8c61\u7684\u4e00\u90e8\u4efd(\u4e00\u4e2a\u5143\u7d20)\uff0c\u8fdb\u884c\u64cd\u4f5c\uff0c\u6240\u4ee5\u6240\u6709\u6307\u5411\u8be5\u5bf9\u8c61\u7684\u5f15\u7528\u90fd\u53d7\u5230\u5f71\u54cd\u3002<\/p>\n<p>\uff08\u4e0e\u4e4b\u5f62\u6210\u5bf9\u6bd4\u7684\u662f\uff0c\u6211\u4eec\u4e4b\u524d\u7684\u8d4b\u503c\u64cd\u4f5c\u90fd\u6ca1\u6709\u5bf9\u5bf9\u8c61\u81ea\u8eab\u53d1\u751f\u4f5c\u7528\uff0c\u53ea\u662f\u6539\u53d8\u5f15\u7528\u6307\u5411\u3002\uff09<\/p>\n<p>\u5217\u8868\u53ef\u4ee5\u901a\u8fc7\u5f15\u7528\u5176\u5143\u7d20\uff0c\u6539\u53d8\u5bf9\u8c61\u81ea\u8eab(in-place change)\u3002\u8fd9\u79cd\u5bf9\u8c61\u7c7b\u578b\uff0c\u79f0\u4e3a\u53ef\u53d8\u6570\u636e\u5bf9\u8c61(mutable object)\uff0c\u8bcd\u5178\u4e5f\u662f\u8fd9\u6837\u7684\u6570\u636e\u7c7b\u578b\u3002<\/p>\n<p>\u800c\u50cf\u4e4b\u524d\u7684\u6570\u5b57\u548c\u5b57\u7b26\u4e32\uff0c\u4e0d\u80fd\u6539\u53d8\u5bf9\u8c61\u672c\u8eab\uff0c\u53ea\u80fd\u6539\u53d8\u5f15\u7528\u7684\u6307\u5411\uff0c\u79f0\u4e3a\u4e0d\u53ef\u53d8\u6570\u636e\u5bf9\u8c61(immutable object)\u3002<\/p>\n<p>\u6211\u4eec\u4e4b\u524d\u5b66\u7684\u5143\u7ec4(tuple)\uff0c\u5c3d\u7ba1\u53ef\u4ee5\u8c03\u7528\u5f15\u7528\u5143\u7d20\uff0c\u4f46\u4e0d\u53ef\u4ee5\u8d4b\u503c\uff0c\u56e0\u6b64\u4e0d\u80fd\u6539\u53d8\u5bf9\u8c61\u81ea\u8eab\uff0c\u6240\u4ee5\u4e5f\u7b97\u662fimmutable object.<\/p>\n<h3>\u4ece\u52a8\u6001\u7c7b\u578b\u770b\u51fd\u6570\u7684\u53c2\u6570\u4f20\u9012<\/h3>\n<p>\u51fd\u6570\u7684\u53c2\u6570\u4f20\u9012\uff0c\u672c\u8d28\u4e0a\u4f20\u9012\u7684\u662f\u5f15\u7528\u3002\u6bd4\u5982\u8bf4\uff1a<\/p>\n<div class=\"cnblogs_code\">\n<pre>def f(x):\n    x = 100\n    print x\n\na = 1\nf(a)\nprint a<\/pre>\n<\/div>\n<p>\u53c2\u6570x\u662f\u4e00\u4e2a\u65b0\u7684\u5f15\u7528\uff0c\u6307\u5411a\u6240\u6307\u7684\u5bf9\u8c61\u3002\u5982\u679c\u53c2\u6570\u662f\u4e0d\u53ef\u53d8(immutable)\u7684\u5bf9\u8c61\uff0ca\u548cx\u5f15\u7528\u4e4b\u95f4\u76f8\u4e92\u72ec\u7acb\u3002\u5bf9\u53c2\u6570x\u7684\u64cd\u4f5c\u4e0d\u4f1a\u5f71\u54cd\u5f15\u7528a\u3002\u8fd9\u6837\u7684\u4f20\u9012\u7c7b\u4f3c\u4e8eC\u8bed\u8a00\u4e2d\u7684\u503c\u4f20\u9012\u3002<\/p>\n<p>\u5982\u679c\u4f20\u9012\u7684\u662f\u53ef\u53d8(mutable)\u7684\u5bf9\u8c61\uff0c\u90a3\u4e48\u6539\u53d8\u51fd\u6570\u53c2\u6570\uff0c\u6709\u53ef\u80fd\u6539\u53d8\u539f\u5bf9\u8c61\u3002\u6240\u6709\u6307\u5411\u539f\u5bf9\u8c61\u7684\u5f15\u7528\u90fd\u4f1a\u53d7\u5f71\u54cd\uff0c\u7f16\u7a0b\u7684\u65f6\u5019\u8981\u5bf9\u6b64\u95ee\u9898\u7559\u5fc3\u3002\u6bd4\u5982\u8bf4\uff1a<\/p>\n<div class=\"cnblogs_code\">\n<pre>def f(x):\n    x[0] = 100\n    print x\n\na = [1,2,3]\nf(a)\nprint a<\/pre>\n<\/div>\n<p>\u52a8\u6001\u7c7b\u578b\u662fPython\u7684\u6838\u5fc3\u673a\u5236\u4e4b\u4e00\u3002\u53ef\u4ee5\u5728\u5e94\u7528\u4e2d\u6162\u6162\u719f\u6089\u3002<\/p>\n<h3>\u603b\u7ed3<\/h3>\n<p>\u5f15\u7528\u548c\u5bf9\u8c61\u7684\u5206\u79bb\uff0c\u5bf9\u8c61\u662f\u5185\u5b58\u4e2d\u50a8\u5b58\u6570\u636e\u7684\u5b9e\u4f53\uff0c\u5f15\u7528\u6307\u5411\u5bf9\u8c61\u3002<\/p>\n<p>\u53ef\u53d8\u5bf9\u8c61\uff0c\u4e0d\u53ef\u53d8\u5bf9\u8c61<\/p>\n<p>\u51fd\u6570\u503c\u4f20\u9012<\/p>\n<\/div>\n<p>\u4f5c\u8005\uff1aVamei \u51fa\u5904\uff1ahttps:\/\/www.cnblogs.com\/vamei<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u52a8\u6001\u7c7b\u578b(dynamic typing)\u662fPython\u53e6\u4e00\u4e2a\u91cd\u8981\u7684\u6838\u5fc3\u6982\u5ff5\u3002\u6211\u4eec\u4e4b\u524d\u8bf4\u8fc7\uff0cPython\u7684\u53d8\u91cf( &#8230; <a title=\"Python\u8fdb\u963609 \u52a8\u6001\u7c7b\u578b\" class=\"read-more\" href=\"https:\/\/cn.hostease.com\/xueyuan\/jishu\/python\/python%e8%bf%9b%e9%98%b609-%e5%8a%a8%e6%80%81%e7%b1%bb%e5%9e%8b\/\" aria-label=\"\u9605\u8bfb Python\u8fdb\u963609 \u52a8\u6001\u7c7b\u578b\">\u9605\u8bfb\u66f4\u591a<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[654],"tags":[672],"class_list":["post-2480","post","type-post","status-publish","format-standard","hentry","category-python","tag-python"],"aioseo_notices":[],"jetpack_featured_media_url":"","jetpack-related-posts":[],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/cn.hostease.com\/xueyuan\/wp-json\/wp\/v2\/posts\/2480","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cn.hostease.com\/xueyuan\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cn.hostease.com\/xueyuan\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cn.hostease.com\/xueyuan\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/cn.hostease.com\/xueyuan\/wp-json\/wp\/v2\/comments?post=2480"}],"version-history":[{"count":2,"href":"https:\/\/cn.hostease.com\/xueyuan\/wp-json\/wp\/v2\/posts\/2480\/revisions"}],"predecessor-version":[{"id":9227,"href":"https:\/\/cn.hostease.com\/xueyuan\/wp-json\/wp\/v2\/posts\/2480\/revisions\/9227"}],"wp:attachment":[{"href":"https:\/\/cn.hostease.com\/xueyuan\/wp-json\/wp\/v2\/media?parent=2480"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cn.hostease.com\/xueyuan\/wp-json\/wp\/v2\/categories?post=2480"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cn.hostease.com\/xueyuan\/wp-json\/wp\/v2\/tags?post=2480"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}