{"id":105,"date":"2026-06-14T09:47:30","date_gmt":"2026-06-14T01:47:30","guid":{"rendered":"https:\/\/www.52runoob.com\/?p=105"},"modified":"2026-06-14T09:47:30","modified_gmt":"2026-06-14T01:47:30","slug":"python3-%e5%91%bd%e5%90%8d%e7%a9%ba%e9%97%b4%e5%92%8c%e4%bd%9c%e7%94%a8%e5%9f%9f","status":"publish","type":"post","link":"https:\/\/www.52runoob.com\/index.php\/2026\/06\/14\/python3-%e5%91%bd%e5%90%8d%e7%a9%ba%e9%97%b4%e5%92%8c%e4%bd%9c%e7%94%a8%e5%9f%9f\/","title":{"rendered":"Python3 \u547d\u540d\u7a7a\u95f4\u548c\u4f5c\u7528\u57df"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">\u5728 Python 3 \u4e2d\uff0c<strong>\u547d\u540d\u7a7a\u95f4\uff08Namespace\uff09<\/strong>\u548c<strong>\u4f5c\u7528\u57df\uff08Scope\uff09<\/strong>\u662f\u7406\u89e3\u53d8\u91cf\u751f\u547d\u5468\u671f\u3001\u89e3\u51b3 <code>NameError<\/code> \u6216 <code>UnboundLocalError<\/code> \u7b49\u8be1\u5f02\u62a5\u9519\u7684\u6838\u5fc3\u57fa\u77f3\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5982\u679c\u7528\u4e00\u53e5\u8bdd\u6982\u62ec\u5b83\u4eec\u7684\u5173\u7cfb\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u547d\u540d\u7a7a\u95f4<\/strong>\u662f<strong>\u5b58\u50a8<\/strong>\u53d8\u91cf\u540d\u548c\u5bf9\u8c61\u6620\u5c04\u5173\u7cfb\u7684\u201c\u5b57\u5178\u201d\uff08Where names live\uff09\u3002<\/li>\n\n\n\n<li><strong>\u4f5c\u7528\u57df<\/strong>\u662f Python \u89e3\u91ca\u5668<strong>\u67e5\u627e<\/strong>\u53d8\u91cf\u540d\u65f6\u9075\u5faa\u7684\u201c\u89c4\u5219\u201d\uff08How names are looked up\uff09\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e0b\u9762\u6211\u5c06\u4ece<strong>\u6838\u5fc3\u6982\u5ff5<\/strong>\u3001<strong>LEGB \u67e5\u627e\u89c4\u5219<\/strong>\u3001<strong>\u6253\u7834\u89c4\u5219\u7684\u5173\u952e\u5b57<\/strong>\u5230<strong>\u5e38\u89c1\u9677\u9631<\/strong>\uff0c\u4e3a\u4f60\u5f7b\u5e95\u8bb2\u900f\u8fd9\u4e2a Python \u8fdb\u9636\u5fc5\u8003\u70b9\u3002<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\u4e00\u3001 \u6838\u5fc3\u6982\u5ff5\uff1a\u4ec0\u4e48\u662f\u547d\u540d\u7a7a\u95f4\uff1f<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728 Python \u4e2d\uff0c\u547d\u540d\u7a7a\u95f4\u672c\u8d28\u4e0a\u5c31\u662f\u4e00\u4e2a<strong>\u5b57\u5178\uff08Dictionary\uff09<\/strong>\uff0c\u952e\u662f\u53d8\u91cf\u540d\uff08\u5b57\u7b26\u4e32\uff09\uff0c\u503c\u662f\u5bf9\u8c61\uff08\u5185\u5b58\u5730\u5740\uff09\u3002Python \u5728\u8fd0\u884c\u65f6\u7ef4\u62a4\u7740\u591a\u4e2a\u76f8\u4e92\u72ec\u7acb\u7684\u547d\u540d\u7a7a\u95f4\uff0c\u5b83\u4eec\u4e92\u4e0d\u5e72\u6270\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e3b\u8981\u5206\u4e3a\u56db\u79cd\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u5185\u7f6e\u547d\u540d\u7a7a\u95f4 (Built-in)<\/strong>\uff1aPython \u542f\u52a8\u65f6\u521b\u5efa\uff0c\u5305\u542b <code>print<\/code>, <code>len<\/code>, <code>Exception<\/code> \u7b49\u5185\u7f6e\u51fd\u6570\u548c\u5f02\u5e38\u3002\u751f\u547d\u5468\u671f\u6700\u957f\u3002<\/li>\n\n\n\n<li><strong>\u5168\u5c40\u547d\u540d\u7a7a\u95f4 (Global)<\/strong>\uff1a\u6bcf\u4e2a\u6a21\u5757\uff08<code>.py<\/code> \u6587\u4ef6\uff09\u5728\u5bfc\u5165\u6216\u8fd0\u884c\u65f6\u521b\u5efa\u3002\u5305\u542b\u6a21\u5757\u7ea7\u522b\u7684\u53d8\u91cf\u3001\u51fd\u6570\u548c\u7c7b\u3002<\/li>\n\n\n\n<li><strong>\u5c40\u90e8\u547d\u540d\u7a7a\u95f4 (Local)<\/strong>\uff1a\u51fd\u6570\u88ab\u8c03\u7528\u65f6\u521b\u5efa\uff0c\u51fd\u6570\u8fd4\u56de\u6216\u629b\u51fa\u5f02\u5e38\u65f6\u9500\u6bc1\u3002\u5305\u542b\u51fd\u6570\u7684\u53c2\u6570\u548c\u5185\u90e8\u53d8\u91cf\u3002<\/li>\n\n\n\n<li><strong>\u5d4c\u5957\/\u95ed\u5305\u547d\u540d\u7a7a\u95f4 (Enclosing)<\/strong>\uff1a\u5f53\u51fd\u6570\u5d4c\u5957\u5b9a\u4e49\u65f6\uff0c\u5916\u5c42\u51fd\u6570\u7684\u5c40\u90e8\u547d\u540d\u7a7a\u95f4\u5bf9\u5185\u5c42\u51fd\u6570\u800c\u8a00\u5c31\u662f Enclosing \u547d\u540d\u7a7a\u95f4\u3002<\/li>\n<\/ol>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\u4e8c\u3001 \u6838\u5fc3\u89c4\u5219\uff1a\u4f5c\u7528\u57df\u4e0e LEGB \u67e5\u627e\u987a\u5e8f \ud83c\udf1f<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u5f53\u4f60\u5728\u4ee3\u7801\u4e2d\u4f7f\u7528\u4e00\u4e2a\u53d8\u91cf\u540d\uff08\u4f8b\u5982 <code>x<\/code>\uff09\u65f6\uff0cPython \u89e3\u91ca\u5668\u4f1a\u6309\u7167 <strong>LEGB<\/strong> \u987a\u5e8f\u4f9d\u6b21\u5728\u547d\u540d\u7a7a\u95f4\u4e2d\u67e5\u627e\uff0c<strong>\u4e00\u65e6\u627e\u5230\u5c31\u505c\u6b62\u67e5\u627e<\/strong>\u3002\u5982\u679c\u56db\u4e2a\u5730\u65b9\u90fd\u627e\u4e0d\u5230\uff0c\u5c31\u4f1a\u629b\u51fa <code>NameError<\/code>\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>LEGB \u987a\u5e8f<\/strong>\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>L<\/strong>ocal (\u5c40\u90e8)\uff1a\u5f53\u524d\u51fd\u6570\u5185\u90e8\u3002<\/li>\n\n\n\n<li><strong>E<\/strong>nclosing (\u5d4c\u5957)\uff1a\u5916\u5c42\u5d4c\u5957\u7684\u51fd\u6570\uff08\u4ece\u5185\u5411\u5916\u627e\uff09\u3002<\/li>\n\n\n\n<li><strong>G<\/strong>lobal (\u5168\u5c40)\uff1a\u5f53\u524d\u6a21\u5757\u7684\u9876\u5c42\u3002<\/li>\n\n\n\n<li><strong>B<\/strong>uilt-in (\u5185\u7f6e)\uff1aPython \u5185\u7f6e\u7684\u547d\u540d\u7a7a\u95f4\u3002<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u4ee3\u7801\u6f14\u793a<\/strong>\uff1a<\/p>\n\n\n\n<div class=\"chp-code-block chp-theme-github-dark chp-wrap-on\" data-chp-language=\"plaintext\" data-chp-line-start=\"1\" data-chp-highlight=\"\"><div class=\"chp-toolbar\"><div class=\"chp-toolbar-left\"><span class=\"chp-dots\"><span><\/span><span><\/span><span><\/span><\/span><span class=\"chp-language-label\">\u7eaf\u6587\u672c<\/span><\/div><div class=\"chp-toolbar-right\"><button type=\"button\" class=\"chp-copy-btn\" aria-label=\"\u590d\u5236\u4ee3\u7801\"><svg class=\"chp-icon-copy\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\"><path fill=\"currentColor\" d=\"M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z\"\/><\/svg><svg class=\"chp-icon-check\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\" style=\"display:none;\"><path fill=\"currentColor\" d=\"M9 16.17L4.83 12l-1.42 1.41L9 19 21 7l-1.41-1.41z\"\/><\/svg><span class=\"chp-copy-text\">\u590d\u5236<\/span><\/button><\/div><\/div><div class=\"chp-code-wrapper\"><div class=\"chp-line-numbers\" aria-hidden=\"true\"><span>1<\/span><span>2<\/span><span>3<\/span><span>4<\/span><span>5<\/span><span>6<\/span><span>7<\/span><span>8<\/span><span>9<\/span><span>10<\/span><span>11<\/span><span>12<\/span><span>13<\/span><span>14<\/span><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\">x = &quot;Global&quot;  # Global \u547d\u540d\u7a7a\u95f4\n\ndef outer_function():\n    x = &quot;Enclosing&quot;  # Enclosing \u547d\u540d\u7a7a\u95f4\n\n    def inner_function():\n        x = &quot;Local&quot;  # Local \u547d\u540d\u7a7a\u95f4\n        print(f&quot;Inner \u627e\u5230: {x}&quot;)\n\n    inner_function()\n    print(f&quot;Outer \u627e\u5230: {x}&quot;)\n\nouter_function()\nprint(f&quot;Module \u627e\u5230: {x}&quot;)<\/code><\/pre><\/div><\/div>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u8f93\u51fa<\/strong>\uff1a<\/p>\n\n\n\n<div class=\"chp-code-block chp-theme-github-dark chp-wrap-on\" data-chp-language=\"plaintext\" data-chp-line-start=\"1\" data-chp-highlight=\"\"><div class=\"chp-toolbar\"><div class=\"chp-toolbar-left\"><span class=\"chp-dots\"><span><\/span><span><\/span><span><\/span><\/span><span class=\"chp-language-label\">\u7eaf\u6587\u672c<\/span><\/div><div class=\"chp-toolbar-right\"><button type=\"button\" class=\"chp-copy-btn\" aria-label=\"\u590d\u5236\u4ee3\u7801\"><svg class=\"chp-icon-copy\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\"><path fill=\"currentColor\" d=\"M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z\"\/><\/svg><svg class=\"chp-icon-check\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\" style=\"display:none;\"><path fill=\"currentColor\" d=\"M9 16.17L4.83 12l-1.42 1.41L9 19 21 7l-1.41-1.41z\"\/><\/svg><span class=\"chp-copy-text\">\u590d\u5236<\/span><\/button><\/div><\/div><div class=\"chp-code-wrapper\"><div class=\"chp-line-numbers\" aria-hidden=\"true\"><span>1<\/span><span>2<\/span><span>3<\/span><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\">Inner \u627e\u5230: Local\nOuter \u627e\u5230: Enclosing\nModule \u627e\u5230: Global<\/code><\/pre><\/div><\/div>\n\n\n\n<p class=\"wp-block-paragraph\"><em>\ud83d\udca1 \u6ce8\u610f\uff1a\u5982\u679c <code>inner_function<\/code> \u4e2d\u6ca1\u6709\u5b9a\u4e49 <code>x<\/code>\uff0c\u5b83\u4f1a\u5411\u4e0a\u627e\u5230 <code>outer_function<\/code> \u7684 <code>x<\/code> (&#8220;Enclosing&#8221;)\uff1b\u5982\u679c\u5916\u5c42\u4e5f\u6ca1\u6709\uff0c\u5b83\u4f1a\u627e\u5230\u5168\u5c40\u7684 <code>x<\/code> (&#8220;Global&#8221;)\u3002<\/em><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\u4e09\u3001 \u6253\u7834\u89c4\u5219\uff1a<code>global<\/code> \u4e0e <code>nonlocal<\/code><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u9ed8\u8ba4\u60c5\u51b5\u4e0b\uff0c<strong>\u5728\u51fd\u6570\u5185\u90e8\u5bf9\u53d8\u91cf\u8d4b\u503c\uff0cPython \u4f1a\u8ba4\u4e3a\u4f60\u5728\u521b\u5efa\u4e00\u4e2a\u65b0\u7684\u5c40\u90e8\u53d8\u91cf<\/strong>\u3002\u5982\u679c\u4f60\u60f3<strong>\u4fee\u6539<\/strong>\u5916\u5c42\u6216\u5168\u5c40\u7684\u53d8\u91cf\uff0c\u5fc5\u987b\u663e\u5f0f\u58f0\u660e\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">1. <code>global<\/code> \u5173\u952e\u5b57\uff1a\u4fee\u6539\u5168\u5c40\u53d8\u91cf<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u544a\u8bc9 Python\uff1a\u201c\u6211\u8981\u4f7f\u7528\u7684\u662f\u5168\u5c40\u547d\u540d\u7a7a\u95f4\u91cc\u7684\u90a3\u4e2a\u53d8\u91cf\uff0c\u4e0d\u8981\u7ed9\u6211\u521b\u5efa\u5c40\u90e8\u53d8\u91cf\u201d\u3002<\/p>\n\n\n\n<div class=\"chp-code-block chp-theme-github-dark chp-wrap-on\" data-chp-language=\"plaintext\" data-chp-line-start=\"1\" data-chp-highlight=\"\"><div class=\"chp-toolbar\"><div class=\"chp-toolbar-left\"><span class=\"chp-dots\"><span><\/span><span><\/span><span><\/span><\/span><span class=\"chp-language-label\">\u7eaf\u6587\u672c<\/span><\/div><div class=\"chp-toolbar-right\"><button type=\"button\" class=\"chp-copy-btn\" aria-label=\"\u590d\u5236\u4ee3\u7801\"><svg class=\"chp-icon-copy\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\"><path fill=\"currentColor\" d=\"M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z\"\/><\/svg><svg class=\"chp-icon-check\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\" style=\"display:none;\"><path fill=\"currentColor\" d=\"M9 16.17L4.83 12l-1.42 1.41L9 19 21 7l-1.41-1.41z\"\/><\/svg><span class=\"chp-copy-text\">\u590d\u5236<\/span><\/button><\/div><\/div><div class=\"chp-code-wrapper\"><div class=\"chp-line-numbers\" aria-hidden=\"true\"><span>1<\/span><span>2<\/span><span>3<\/span><span>4<\/span><span>5<\/span><span>6<\/span><span>7<\/span><span>8<\/span><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\">count = 0  # \u5168\u5c40\u53d8\u91cf\n\ndef increment():\n    global count  # \u58f0\u660e\u4f7f\u7528\u5168\u5c40\u7684 count\n    count += 1    # \u4fee\u6539\u5168\u5c40\u53d8\u91cf\n\nincrement()\nprint(count)  # \u8f93\u51fa: 1<\/code><\/pre><\/div><\/div>\n\n\n\n<h4 class=\"wp-block-heading\">2. <code>nonlocal<\/code> \u5173\u952e\u5b57\uff1a\u4fee\u6539\u5d4c\u5957\u5916\u5c42\u53d8\u91cf (Python 3 \u4e13\u5c5e)<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u544a\u8bc9 Python\uff1a\u201c\u6211\u8981\u4f7f\u7528\u7684\u662f\u6700\u8fd1\u4e00\u5c42\u5916\u5c42\u51fd\u6570\uff08Enclosing\uff09\u7684\u53d8\u91cf\uff0c\u4e0d\u662f\u5168\u5c40\u7684\uff0c\u4e5f\u4e0d\u662f\u5c40\u90e8\u7684\u201d\u3002\u8fd9\u662f\u5b9e\u73b0<strong>\u95ed\u5305 (Closure)<\/strong> \u7684\u5173\u952e\u3002<\/p>\n\n\n\n<div class=\"chp-code-block chp-theme-github-dark chp-wrap-on\" data-chp-language=\"plaintext\" data-chp-line-start=\"1\" data-chp-highlight=\"\"><div class=\"chp-toolbar\"><div class=\"chp-toolbar-left\"><span class=\"chp-dots\"><span><\/span><span><\/span><span><\/span><\/span><span class=\"chp-language-label\">\u7eaf\u6587\u672c<\/span><\/div><div class=\"chp-toolbar-right\"><button type=\"button\" class=\"chp-copy-btn\" aria-label=\"\u590d\u5236\u4ee3\u7801\"><svg class=\"chp-icon-copy\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\"><path fill=\"currentColor\" d=\"M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z\"\/><\/svg><svg class=\"chp-icon-check\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\" style=\"display:none;\"><path fill=\"currentColor\" d=\"M9 16.17L4.83 12l-1.42 1.41L9 19 21 7l-1.41-1.41z\"\/><\/svg><span class=\"chp-copy-text\">\u590d\u5236<\/span><\/button><\/div><\/div><div class=\"chp-code-wrapper\"><div class=\"chp-line-numbers\" aria-hidden=\"true\"><span>1<\/span><span>2<\/span><span>3<\/span><span>4<\/span><span>5<\/span><span>6<\/span><span>7<\/span><span>8<\/span><span>9<\/span><span>10<\/span><span>11<\/span><span>12<\/span><span>13<\/span><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\">def make_counter():\n    count = 0  # Enclosing \u53d8\u91cf\n\n    def counter():\n        nonlocal count  # \u58f0\u660e\u4f7f\u7528\u5916\u5c42\u7684 count\n        count += 1\n        return count\n\n    return counter\n\nmy_counter = make_counter()\nprint(my_counter())  # \u8f93\u51fa: 1\nprint(my_counter())  # \u8f93\u51fa: 2 (\u72b6\u6001\u88ab\u4fdd\u7559\u5728\u4e86\u95ed\u5305\u4e2d)<\/code><\/pre><\/div><\/div>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\u56db\u3001 \u26a0\ufe0f \u4e09\u5927\u7ecf\u5178\u9677\u9631 (\u9762\u8bd5\u9ad8\u9891)<\/h3>\n\n\n\n<h4 class=\"wp-block-heading\">\u9677\u9631 1\uff1a<code>UnboundLocalError<\/code> (\u5c40\u90e8\u53d8\u91cf\u8d4b\u503c\u524d\u88ab\u5f15\u7528)<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u662f Python \u521d\u5b66\u8005\u6700\u5bb9\u6613\u9047\u5230\u7684\u8be1\u5f02\u62a5\u9519\u3002<\/p>\n\n\n\n<div class=\"chp-code-block chp-theme-github-dark chp-wrap-on\" data-chp-language=\"plaintext\" data-chp-line-start=\"1\" data-chp-highlight=\"\"><div class=\"chp-toolbar\"><div class=\"chp-toolbar-left\"><span class=\"chp-dots\"><span><\/span><span><\/span><span><\/span><\/span><span class=\"chp-language-label\">\u7eaf\u6587\u672c<\/span><\/div><div class=\"chp-toolbar-right\"><button type=\"button\" class=\"chp-copy-btn\" aria-label=\"\u590d\u5236\u4ee3\u7801\"><svg class=\"chp-icon-copy\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\"><path fill=\"currentColor\" d=\"M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z\"\/><\/svg><svg class=\"chp-icon-check\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\" style=\"display:none;\"><path fill=\"currentColor\" d=\"M9 16.17L4.83 12l-1.42 1.41L9 19 21 7l-1.41-1.41z\"\/><\/svg><span class=\"chp-copy-text\">\u590d\u5236<\/span><\/button><\/div><\/div><div class=\"chp-code-wrapper\"><div class=\"chp-line-numbers\" aria-hidden=\"true\"><span>1<\/span><span>2<\/span><span>3<\/span><span>4<\/span><span>5<\/span><span>6<\/span><span>7<\/span><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\">x = 10\n\ndef bad_function():\n    print(x)  # \u274c UnboundLocalError: local variable &#039;x&#039; referenced before assignment\n    x = 20    # \u56e0\u4e3a\u8fd9\u91cc\u6709\u8d4b\u503c\u64cd\u4f5c\uff0cPython \u5728\u7f16\u8bd1\u65f6\u5c31\u5224\u5b9a x \u662f\u5c40\u90e8\u53d8\u91cf\n\nbad_function()<\/code><\/pre><\/div><\/div>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u539f\u7406\u89e3\u6790<\/strong>\uff1aPython \u5728\u7f16\u8bd1\u51fd\u6570\u65f6\uff0c\u53d1\u73b0\u51fd\u6570\u4f53\u5185\u6709 <code>x = 20<\/code>\uff0c\u5c31\u4f1a\u628a <code>x<\/code> \u6807\u8bb0\u4e3a<strong>\u5c40\u90e8\u53d8\u91cf<\/strong>\u3002\u4f46\u5728\u6267\u884c <code>print(x)<\/code> \u65f6\uff0c\u5c40\u90e8\u53d8\u91cf <code>x<\/code> \u8fd8\u6ca1\u6709\u88ab\u8d4b\u503c\uff0c\u56e0\u6b64\u62a5\u9519\u3002<br><strong>\u2705 \u89e3\u51b3\u65b9\u6cd5<\/strong>\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u5982\u679c\u60f3\u4fee\u6539\u5168\u5c40\u53d8\u91cf\uff0c\u52a0\u4e0a <code>global x<\/code>\u3002<\/li>\n\n\n\n<li>\u5982\u679c\u53ea\u662f\u8bfb\u53d6\uff0c\u4e0d\u8981\u5728\u540c\u51fd\u6570\u5185\u5bf9\u5176\u91cd\u65b0\u8d4b\u503c\uff1b\u6216\u8005\u5c06\u5176\u4f5c\u4e3a\u53c2\u6570\u4f20\u5165\u3002<\/li>\n<\/ol>\n\n\n\n<h4 class=\"wp-block-heading\">\u9677\u9631 2\uff1a\u4fee\u6539\u53ef\u53d8\u5bf9\u8c61 vs \u91cd\u65b0\u8d4b\u503c<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u5982\u679c\u5168\u5c40\/\u5916\u5c42\u53d8\u91cf\u662f<strong>\u53ef\u53d8\u5bf9\u8c61<\/strong>\uff08\u5982\u5217\u8868\u3001\u5b57\u5178\uff09\uff0c\u4f60<strong>\u4e0d\u9700\u8981<\/strong> <code>global<\/code> \u6216 <code>nonlocal<\/code> \u5c31\u80fd\u4fee\u6539\u5b83\u7684<strong>\u5185\u5bb9<\/strong>\uff0c\u4f46<strong>\u91cd\u65b0\u8d4b\u503c<\/strong>\u6574\u4e2a\u53d8\u91cf\u4ecd\u7136\u9700\u8981\u5173\u952e\u5b57\u3002<\/p>\n\n\n\n<div class=\"chp-code-block chp-theme-github-dark chp-wrap-on\" data-chp-language=\"plaintext\" data-chp-line-start=\"1\" data-chp-highlight=\"\"><div class=\"chp-toolbar\"><div class=\"chp-toolbar-left\"><span class=\"chp-dots\"><span><\/span><span><\/span><span><\/span><\/span><span class=\"chp-language-label\">\u7eaf\u6587\u672c<\/span><\/div><div class=\"chp-toolbar-right\"><button type=\"button\" class=\"chp-copy-btn\" aria-label=\"\u590d\u5236\u4ee3\u7801\"><svg class=\"chp-icon-copy\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\"><path fill=\"currentColor\" d=\"M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z\"\/><\/svg><svg class=\"chp-icon-check\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\" style=\"display:none;\"><path fill=\"currentColor\" d=\"M9 16.17L4.83 12l-1.42 1.41L9 19 21 7l-1.41-1.41z\"\/><\/svg><span class=\"chp-copy-text\">\u590d\u5236<\/span><\/button><\/div><\/div><div class=\"chp-code-wrapper\"><div class=\"chp-line-numbers\" aria-hidden=\"true\"><span>1<\/span><span>2<\/span><span>3<\/span><span>4<\/span><span>5<\/span><span>6<\/span><span>7<\/span><span>8<\/span><span>9<\/span><span>10<\/span><span>11<\/span><span>12<\/span><span>13<\/span><span>14<\/span><span>15<\/span><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\">my_list = [1, 2, 3]\nmy_dict = {&quot;a&quot;: 1}\n\ndef modify_data():\n    # \u2705 \u4e0d\u9700\u8981 global\uff0c\u76f4\u63a5\u4fee\u6539\u5bf9\u8c61\u5185\u90e8\u72b6\u6001\u662f\u5141\u8bb8\u7684\n    my_list.append(4)\n    my_dict[&quot;b&quot;] = 2\n\n    # \u274c \u9700\u8981 global\uff0c\u56e0\u4e3a\u8fd9\u662f\u91cd\u65b0\u7ed1\u5b9a\u53d8\u91cf\u540d\u5230\u4e00\u4e2a\u65b0\u5bf9\u8c61\n    # global my_list\n    # my_list = [9, 9, 9] \n\nmodify_data()\nprint(my_list)  # [1, 2, 3, 4]\nprint(my_dict)  # {&#039;a&#039;: 1, &#039;b&#039;: 2}<\/code><\/pre><\/div><\/div>\n\n\n\n<h4 class=\"wp-block-heading\">\u9677\u9631 3\uff1a\u95ed\u5305\u4e2d\u7684\u5ef6\u8fdf\u7ed1\u5b9a (Late Binding)<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u4e0e\u4e4b\u524d\u8bb2 <code>lambda<\/code> \u65f6\u63d0\u5230\u7684\u9677\u9631\u540c\u6e90\u3002\u5faa\u73af\u4e2d\u521b\u5efa\u7684\u95ed\u5305\uff0c\u4f1a\u5f15\u7528\u5faa\u73af\u53d8\u91cf\u7684<strong>\u6700\u7ec8\u503c<\/strong>\uff0c\u800c\u4e0d\u662f\u521b\u5efa\u65f6\u7684\u503c\u3002<\/p>\n\n\n\n<div class=\"chp-code-block chp-theme-github-dark chp-wrap-on\" data-chp-language=\"plaintext\" data-chp-line-start=\"1\" data-chp-highlight=\"\"><div class=\"chp-toolbar\"><div class=\"chp-toolbar-left\"><span class=\"chp-dots\"><span><\/span><span><\/span><span><\/span><\/span><span class=\"chp-language-label\">\u7eaf\u6587\u672c<\/span><\/div><div class=\"chp-toolbar-right\"><button type=\"button\" class=\"chp-copy-btn\" aria-label=\"\u590d\u5236\u4ee3\u7801\"><svg class=\"chp-icon-copy\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\"><path fill=\"currentColor\" d=\"M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z\"\/><\/svg><svg class=\"chp-icon-check\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\" style=\"display:none;\"><path fill=\"currentColor\" d=\"M9 16.17L4.83 12l-1.42 1.41L9 19 21 7l-1.41-1.41z\"\/><\/svg><span class=\"chp-copy-text\">\u590d\u5236<\/span><\/button><\/div><\/div><div class=\"chp-code-wrapper\"><div class=\"chp-line-numbers\" aria-hidden=\"true\"><span>1<\/span><span>2<\/span><span>3<\/span><span>4<\/span><span>5<\/span><span>6<\/span><span>7<\/span><span>8<\/span><span>9<\/span><span>10<\/span><span>11<\/span><span>12<\/span><span>13<\/span><span>14<\/span><span>15<\/span><span>16<\/span><span>17<\/span><span>18<\/span><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\">def create_multipliers():\n    multipliers = []\n    for i in range(3):\n        # i \u662f\u5728 Enclosing \u4f5c\u7528\u57df\u4e2d\u67e5\u627e\u7684\n        multipliers.append(lambda x: x * i)\n    return multipliers\n\nfuncs = create_multipliers()\nprint([f(2) for f in funcs])  \n# \u274c \u671f\u671b\u8f93\u51fa: [0, 2, 4]\n# \u2705 \u5b9e\u9645\u8f93\u51fa: [4, 4, 4] (\u56e0\u4e3a\u5faa\u73af\u7ed3\u675f\u65f6 i \u7684\u503c\u662f 2)\n\n# \u2705 \u6b63\u786e\u89e3\u6cd5\uff1a\u4f7f\u7528\u9ed8\u8ba4\u53c2\u6570\u5f3a\u5236\u5728\u521b\u5efa\u65f6\u7ed1\u5b9a\u5f53\u524d\u503c\ndef create_multipliers_fixed():\n    multipliers = []\n    for i in range(3):\n        multipliers.append(lambda x, i=i: x * i) # i=i \u662f\u5173\u952e\n    return multipliers<\/code><\/pre><\/div><\/div>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\u4e94\u3001 \u6700\u4f73\u5b9e\u8df5\u4e0e\u907f\u5751\u6307\u5357<\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u5c3d\u91cf\u907f\u514d\u4f7f\u7528 <code>global<\/code><\/strong>\uff1a\u5168\u5c40\u72b6\u6001\u662f Bug \u7684\u6e29\u5e8a\uff0c\u4f1a\u5bfc\u81f4\u4ee3\u7801\u96be\u4ee5\u6d4b\u8bd5\u548c\u7ef4\u62a4\u3002\u4f18\u5148\u901a\u8fc7<strong>\u51fd\u6570\u53c2\u6570\u4f20\u9012<\/strong>\u548c<strong>\u8fd4\u56de\u503c<\/strong>\u6765\u5171\u4eab\u6570\u636e\u3002<\/li>\n\n\n\n<li><strong>\u8c28\u614e\u4f7f\u7528\u4e0e\u5185\u7f6e\u51fd\u6570\u540c\u540d\u7684\u53d8\u91cf<\/strong>\uff1a<\/li>\n<\/ol>\n\n\n\n<div class=\"chp-code-block chp-theme-github-dark chp-wrap-on\" data-chp-language=\"plaintext\" data-chp-line-start=\"1\" data-chp-highlight=\"\"><div class=\"chp-toolbar\"><div class=\"chp-toolbar-left\"><span class=\"chp-dots\"><span><\/span><span><\/span><span><\/span><\/span><span class=\"chp-language-label\">\u7eaf\u6587\u672c<\/span><\/div><div class=\"chp-toolbar-right\"><button type=\"button\" class=\"chp-copy-btn\" aria-label=\"\u590d\u5236\u4ee3\u7801\"><svg class=\"chp-icon-copy\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\"><path fill=\"currentColor\" d=\"M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z\"\/><\/svg><svg class=\"chp-icon-check\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\" style=\"display:none;\"><path fill=\"currentColor\" d=\"M9 16.17L4.83 12l-1.42 1.41L9 19 21 7l-1.41-1.41z\"\/><\/svg><span class=\"chp-copy-text\">\u590d\u5236<\/span><\/button><\/div><\/div><div class=\"chp-code-wrapper\"><div class=\"chp-line-numbers\" aria-hidden=\"true\"><span>1<\/span><span>2<\/span><span>3<\/span><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\">   # \u274c \u707e\u96be\uff1a\u8986\u76d6\u4e86\u5185\u7f6e\u7684 list \u51fd\u6570\n   list = [1, 2, 3]\n   my_new_list = list(&quot;hello&quot;) # TypeError: &#039;list&#039; object is not callable<\/code><\/pre><\/div><\/div>\n\n\n\n<ol start=\"3\" class=\"wp-block-list\">\n<li><strong>\u4fdd\u6301\u4f5c\u7528\u57df\u6241\u5e73<\/strong>\uff1a\u5d4c\u5957\u51fd\u6570\u4e0d\u8981\u8d85\u8fc7 2-3 \u5c42\u3002\u5982\u679c\u5d4c\u5957\u592a\u6df1\uff0c\u8003\u8651\u5c06\u5176\u91cd\u6784\u4e3a\u72ec\u7acb\u7684\u7c7b\uff08\u4f7f\u7528 <code>self<\/code> \u7ba1\u7406\u72b6\u6001\uff09\u6216\u72ec\u7acb\u7684\u6a21\u5757\u3002<\/li>\n\n\n\n<li><strong>\u5229\u7528 <code>globals()<\/code> \u548c <code>locals()<\/code> \u8fdb\u884c\u8c03\u8bd5<\/strong>\uff1a<br>\u8fd9\u4e24\u4e2a\u5185\u7f6e\u51fd\u6570\u4f1a\u8fd4\u56de\u5f53\u524d\u4f5c\u7528\u57df\u7684\u547d\u540d\u7a7a\u95f4\u5b57\u5178\u3002\u867d\u7136\u751f\u4ea7\u4ee3\u7801\u4e2d\u6781\u5c11\u4f7f\u7528\uff0c\u4f46\u5728\u8c03\u8bd5\u65f6\u975e\u5e38\u6709\u7528\u3002<\/li>\n<\/ol>\n\n\n\n<div class=\"chp-code-block chp-theme-github-dark chp-wrap-on\" data-chp-language=\"plaintext\" data-chp-line-start=\"1\" data-chp-highlight=\"\"><div class=\"chp-toolbar\"><div class=\"chp-toolbar-left\"><span class=\"chp-dots\"><span><\/span><span><\/span><span><\/span><\/span><span class=\"chp-language-label\">\u7eaf\u6587\u672c<\/span><\/div><div class=\"chp-toolbar-right\"><button type=\"button\" class=\"chp-copy-btn\" aria-label=\"\u590d\u5236\u4ee3\u7801\"><svg class=\"chp-icon-copy\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\"><path fill=\"currentColor\" d=\"M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z\"\/><\/svg><svg class=\"chp-icon-check\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\" style=\"display:none;\"><path fill=\"currentColor\" d=\"M9 16.17L4.83 12l-1.42 1.41L9 19 21 7l-1.41-1.41z\"\/><\/svg><span class=\"chp-copy-text\">\u590d\u5236<\/span><\/button><\/div><\/div><div class=\"chp-code-wrapper\"><div class=\"chp-line-numbers\" aria-hidden=\"true\"><span>1<\/span><span>2<\/span><span>3<\/span><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\">   def debug_scope():\n       a = 1\n       print(locals())  # \u8f93\u51fa: {&#039;a&#039;: 1}<\/code><\/pre><\/div><\/div>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\u603b\u7ed3<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u547d\u540d\u7a7a\u95f4<\/strong>\u662f\u5b57\u5178\uff0c<strong>\u4f5c\u7528\u57df<\/strong>\u662f LEGB \u67e5\u627e\u89c4\u5219\u3002<\/li>\n\n\n\n<li>\u8bfb\u53d6\u53d8\u91cf\uff1a\u9075\u5faa LEGB\uff0c\u81ea\u52a8\u5411\u4e0a\u67e5\u627e\u3002<\/li>\n\n\n\n<li>\u4fee\u6539\u4e0d\u53ef\u53d8\u53d8\u91cf\uff1a\u5fc5\u987b\u4f7f\u7528 <code>global<\/code> (\u6539\u5168\u5c40) \u6216 <code>nonlocal<\/code> (\u6539\u5916\u5c42)\u3002<\/li>\n\n\n\n<li>\u4fee\u6539\u53ef\u53d8\u53d8\u91cf\u5185\u5bb9\uff1a\u65e0\u9700\u5173\u952e\u5b57\uff0c\u76f4\u63a5\u8c03\u7528\u65b9\u6cd5\uff08\u5982 <code>.append()<\/code>\uff09\u5373\u53ef\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u7406\u89e3\u4e86 LEGB \u548c <code>nonlocal<\/code>\uff0c\u4f60\u5c31\u6253\u901a\u4e86 Python \u51fd\u6570\u5f0f\u7f16\u7a0b\uff08\u5982\u88c5\u9970\u5668\u3001\u95ed\u5305\uff09\u548c\u9762\u5411\u5bf9\u8c61\u7f16\u7a0b\u4e2d\u72b6\u6001\u7ba1\u7406\u7684\u4efb\u7763\u4e8c\u8109\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4f60\u5728\u5199\u4ee3\u7801\u65f6\uff0c\u6709\u6ca1\u6709\u9047\u5230\u8fc7\u83ab\u540d\u5176\u5999\u7684 <code>UnboundLocalError<\/code> \u6216\u8005\u53d8\u91cf\u503c\u4e0d\u7b26\u5408\u9884\u671f\u7684\u60c5\u51b5\uff1f\u53ef\u4ee5\u53d1\u51fa\u6765\uff0c\u6211\u4eec\u7528 LEGB \u89c4\u5219\u4e00\u8d77\u62c6\u89e3\u5b83\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5728 Python 3 \u4e2d\uff0c\u547d\u540d\u7a7a\u95f4\uff08Namespa&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[],"class_list":["post-105","post","type-post","status-publish","format-standard","hentry","category-python-3-"],"_links":{"self":[{"href":"https:\/\/www.52runoob.com\/index.php\/wp-json\/wp\/v2\/posts\/105","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.52runoob.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.52runoob.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.52runoob.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.52runoob.com\/index.php\/wp-json\/wp\/v2\/comments?post=105"}],"version-history":[{"count":1,"href":"https:\/\/www.52runoob.com\/index.php\/wp-json\/wp\/v2\/posts\/105\/revisions"}],"predecessor-version":[{"id":106,"href":"https:\/\/www.52runoob.com\/index.php\/wp-json\/wp\/v2\/posts\/105\/revisions\/106"}],"wp:attachment":[{"href":"https:\/\/www.52runoob.com\/index.php\/wp-json\/wp\/v2\/media?parent=105"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.52runoob.com\/index.php\/wp-json\/wp\/v2\/categories?post=105"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.52runoob.com\/index.php\/wp-json\/wp\/v2\/tags?post=105"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}