{"id":62,"date":"2026-06-13T16:50:30","date_gmt":"2026-06-13T08:50:30","guid":{"rendered":"https:\/\/www.52runoob.com\/?p=62"},"modified":"2026-06-13T16:50:30","modified_gmt":"2026-06-13T08:50:30","slug":"python3-%e5%be%aa%e7%8e%af%e8%af%ad%e5%8f%a5","status":"publish","type":"post","link":"https:\/\/www.52runoob.com\/index.php\/2026\/06\/13\/python3-%e5%be%aa%e7%8e%af%e8%af%ad%e5%8f%a5\/","title":{"rendered":"Python3 \u5faa\u73af\u8bed\u53e5"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">\u5728 Python 3 \u4e2d\uff0c<strong>\u5faa\u73af\u8bed\u53e5 (Loop Statements)<\/strong> \u662f\u63a7\u5236\u7a0b\u5e8f\u6d41\u3001\u5b9e\u73b0\u91cd\u590d\u6267\u884c\u903b\u8f91\u7684\u6838\u5fc3\u673a\u5236\u3002\u4e0e\u5176\u4ed6\u8bed\u8a00\uff08\u5982 C \u6216 Java\uff09\u4e0d\u540c\uff0cPython \u7684 <code>for<\/code> \u5faa\u73af\u672c\u8d28\u4e0a\u662f <strong>\u201cfor-each\u201d \u5faa\u73af<\/strong>\uff0c\u5b83\u76f4\u63a5\u904d\u5386\u53ef\u8fed\u4ee3\u5bf9\u8c61\u4e2d\u7684\u5143\u7d20\uff0c\u800c\u4e0d\u662f\u901a\u8fc7\u7d22\u5f15\u8ba1\u6570\u5668\u6765\u63a7\u5236\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e3a\u4e86\u8ba9\u4f60\u5168\u9762\u3001\u6df1\u5165\u5730\u638c\u63e1 Python 3 \u7684\u5faa\u73af\u673a\u5236\uff0c\u672c\u6587\u5c06\u4ece\u5e95\u5c42\u539f\u7406\u3001\u57fa\u7840\u8bed\u6cd5\u3001\u9ad8\u7ea7\u6280\u5de7\u3001\u6807\u51c6\u5e93\u5229\u5668\u5230\u6027\u80fd\u4f18\u5316\u8fdb\u884c\u5168\u65b9\u4f4d\u3001\u8be6\u5c3d\u7684\u89e3\u6790\u3002\uff08\u672c\u6587\u7bc7\u5e45\u8f83\u957f\uff0c\u65e8\u5728\u63d0\u4f9b\u4e00\u4efd\u53ef\u4f5c\u4e3a\u751f\u4ea7\u73af\u5883\u53c2\u8003\u624b\u518c\u7684\u6df1\u5ea6\u6307\u5357\uff09<\/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 \u5faa\u73af\u7684\u5e95\u5c42\u57fa\u77f3\uff1a\u53ef\u8fed\u4ee3\u5bf9\u8c61\u4e0e\u8fed\u4ee3\u5668<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u8981\u771f\u6b63\u638c\u63e1 Python \u7684\u5faa\u73af\uff0c\u5fc5\u987b\u5148\u7406\u89e3\u4e24\u4e2a\u6838\u5fc3\u6982\u5ff5\uff1a<strong>\u53ef\u8fed\u4ee3\u5bf9\u8c61 (Iterable)<\/strong> \u548c <strong>\u8fed\u4ee3\u5668 (Iterator)<\/strong>\u3002<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u53ef\u8fed\u4ee3\u5bf9\u8c61 (Iterable)<\/strong>\uff1a\u4efb\u4f55\u53ef\u4ee5\u88ab <code>for<\/code> \u5faa\u73af\u904d\u5386\u7684\u5bf9\u8c61\u3002\u5728\u5e95\u5c42\uff0c\u5b83\u5fc5\u987b\u5b9e\u73b0\u4e86 <code>__iter__()<\/code> \u65b9\u6cd5\uff0c\u8be5\u65b9\u6cd5\u8fd4\u56de\u4e00\u4e2a\u8fed\u4ee3\u5668\u3002\u5e38\u89c1\u7684 Iterable \u5305\u62ec\uff1a\u5217\u8868\u3001\u5143\u7ec4\u3001\u5b57\u7b26\u4e32\u3001\u5b57\u5178\u3001\u96c6\u5408\uff0c\u4ee5\u53ca <code>range()<\/code> \u7684\u8fd4\u56de\u503c\u3002<\/li>\n\n\n\n<li><strong>\u8fed\u4ee3\u5668 (Iterator)<\/strong>\uff1a\u8868\u793a\u6570\u636e\u6d41\u7684\u5bf9\u8c61\u3002\u5b83\u5fc5\u987b\u540c\u65f6\u5b9e\u73b0 <code>__iter__()<\/code> \u548c <code>__next__()<\/code> \u65b9\u6cd5\u3002\u6bcf\u6b21\u8c03\u7528 <code>__next__()<\/code> \u65f6\uff0c\u5b83\u8fd4\u56de\u4e0b\u4e00\u4e2a\u5143\u7d20\uff1b\u5f53\u6ca1\u6709\u5143\u7d20\u65f6\uff0c\u629b\u51fa <code>StopIteration<\/code> \u5f02\u5e38\uff0c\u4ece\u800c\u901a\u77e5 <code>for<\/code> \u5faa\u73af\u7ed3\u675f\u3002<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><code>for<\/code> \u5faa\u73af\u7684\u5e95\u5c42\u6267\u884c\u8fc7\u7a0b<\/strong>\uff1a<br>\u5f53\u4f60\u5199\u4e0b <code>for item in my_list:<\/code> \u65f6\uff0cPython \u89e3\u91ca\u5668\u5728\u5e95\u5c42\u5b9e\u9645\u6267\u884c\u4e86\u4ee5\u4e0b\u64cd\u4f5c\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><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\"># 1. \u83b7\u53d6\u8fed\u4ee3\u5668\niterator = iter(my_list)  # \u8c03\u7528 my_list.__iter__()\n\nwhile True:\n    try:\n        # 2. \u83b7\u53d6\u4e0b\u4e00\u4e2a\u5143\u7d20\n        item = next(iterator)  # \u8c03\u7528 iterator.__next__()\n        # 3. \u6267\u884c\u5faa\u73af\u4f53\n        print(item)\n    except StopIteration:\n        # 4. \u6355\u83b7\u5f02\u5e38\uff0c\u4f18\u96c5\u9000\u51fa\u5faa\u73af\n        break<\/code><\/pre><\/div><\/div>\n\n\n\n<p class=\"wp-block-paragraph\">\u7406\u89e3\u8fd9\u4e00\u70b9\u81f3\u5173\u91cd\u8981\uff1a\u5b83\u89e3\u91ca\u4e86\u4e3a\u4ec0\u4e48\u4f60\u4e0d\u80fd\u5bf9\u6574\u6570 (<code>int<\/code>) \u4f7f\u7528 <code>for<\/code> \u5faa\u73af\uff08\u56e0\u4e3a\u6574\u6570\u4e0d\u662f Iterable\uff09\uff0c\u4e5f\u89e3\u91ca\u4e86\u4e3a\u4ec0\u4e48\u5728\u904d\u5386\u5b57\u5178\u65f6\uff0c\u76f4\u63a5\u904d\u5386\u5f97\u5230\u7684\u662f\u952e (Keys)\u3002<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\u4e8c\u3001 <code>for<\/code> \u5faa\u73af\u8be6\u89e3<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><code>for<\/code> \u5faa\u73af\u662f Python \u4e2d\u6700\u5e38\u7528\u7684\u5faa\u73af\u7ed3\u6784\uff0c\u7528\u4e8e\u904d\u5386\u5e8f\u5217\u6216\u5176\u4ed6\u53ef\u8fed\u4ee3\u5bf9\u8c61\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">1. \u57fa\u7840\u904d\u5386<\/h4>\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\"># \u904d\u5386\u5217\u8868\nfruits = [&quot;apple&quot;, &quot;banana&quot;, &quot;cherry&quot;]\nfor fruit in fruits:\n    print(fruit)\n\n# \u904d\u5386\u5b57\u7b26\u4e32\nfor char in &quot;Python&quot;:\n    print(char, end=&quot; &quot;)  # \u8f93\u51fa: P y t h o n <\/code><\/pre><\/div><\/div>\n\n\n\n<h4 class=\"wp-block-heading\">2. <code>range()<\/code> \u51fd\u6570\u7684\u8fdb\u9636\u7528\u6cd5<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728 Python 3 \u4e2d\uff0c<code>range()<\/code> \u4e0d\u518d\u8fd4\u56de\u5217\u8868\uff0c\u800c\u662f\u8fd4\u56de\u4e00\u4e2a<strong>\u60f0\u6027\u6c42\u503c (Lazy Evaluation)<\/strong> \u7684 <code>range<\/code> \u5bf9\u8c61\uff0c\u5b83\u53ea\u5360\u7528\u6781\u5c11\u7684\u5185\u5b58\uff08\u65e0\u8bba\u8303\u56f4\u591a\u5927\uff09\uff0c\u4ec5\u5728\u9700\u8981\u65f6\u751f\u6210\u6570\u5b57\u3002<br>\u8bed\u6cd5\uff1a<code>range(start, stop, step)<\/code><\/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\"># 1. \u5355\u4e2a\u53c2\u6570\uff1a\u4ece 0 \u5f00\u59cb\uff0c\u5230 stop-1 \u7ed3\u675f\nfor i in range(5):\n    print(i)  # 0, 1, 2, 3, 4\n\n# 2. \u4e24\u4e2a\u53c2\u6570\uff1a\u6307\u5b9a start \u548c stop\nfor i in range(2, 6):\n    print(i)  # 2, 3, 4, 5\n\n# 3. \u4e09\u4e2a\u53c2\u6570\uff1a\u6307\u5b9a\u6b65\u957f (step)\nfor i in range(0, 10, 2):\n    print(i)  # 0, 2, 4, 6, 8 (\u5076\u6570)\n\n# 4. \u8d1f\u6570\u6b65\u957f\uff1a\u7528\u4e8e\u5012\u5e8f\u904d\u5386\nfor i in range(5, 0, -1):\n    print(i)  # 5, 4, 3, 2, 1<\/code><\/pre><\/div><\/div>\n\n\n\n<h4 class=\"wp-block-heading\">3. \u904d\u5386\u5b57\u5178 (Dictionary)<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u5b57\u5178\u6709\u4e09\u79cd\u89c6\u56fe\uff0c\u51b3\u5b9a\u4e86 <code>for<\/code> \u5faa\u73af\u7684\u904d\u5386\u5185\u5bb9\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><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\">user = {&quot;name&quot;: &quot;Alice&quot;, &quot;age&quot;: 28, &quot;city&quot;: &quot;NY&quot;}\n\n# \u9ed8\u8ba4\u904d\u5386\u952e (\u7b49\u540c\u4e8e user.keys())\nfor key in user:\n    print(key)\n\n# \u904d\u5386\u503c\nfor value in user.values():\n    print(value)\n\n# \u904d\u5386\u952e\u503c\u5bf9 (\u6700\u5e38\u7528\uff0c\u7ed3\u5408\u5143\u7ec4\u89e3\u5305)\nfor key, value in user.items():\n    print(f&quot;{key}: {value}&quot;)<\/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\">\u4e09\u3001 <code>while<\/code> \u5faa\u73af\u8be6\u89e3<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><code>while<\/code> \u5faa\u73af\u5728<strong>\u6761\u4ef6\u4e3a\u771f<\/strong>\u65f6\u6301\u7eed\u6267\u884c\u4ee3\u7801\u5757\u3002\u5b83\u9002\u7528\u4e8e<strong>\u5faa\u73af\u6b21\u6570\u672a\u77e5<\/strong>\uff0c\u4ec5\u4f9d\u8d56\u67d0\u4e2a\u72b6\u6001\u6216\u6761\u4ef6\u6765\u51b3\u5b9a\u662f\u5426\u7ee7\u7eed\u7684\u573a\u666f\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><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\">count = 0\nwhile count &lt; 3:\n    print(f&quot;Count is {count}&quot;)\n    count += 1  # \u26a0\ufe0f \u5fc5\u987b\u66f4\u65b0\u6761\u4ef6\u53d8\u91cf\uff0c\u5426\u5219\u4f1a\u5bfc\u81f4\u65e0\u9650\u5faa\u73af (Infinite Loop)<\/code><\/pre><\/div><\/div>\n\n\n\n<h4 class=\"wp-block-heading\">\u26a0\ufe0f <code>while<\/code> \u5faa\u73af\u7684\u5e38\u89c1\u9677\u9631<\/h4>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u5fd8\u8bb0\u66f4\u65b0\u5faa\u73af\u53d8\u91cf<\/strong>\uff1a\u5bfc\u81f4\u6b7b\u5faa\u73af\uff0c\u8017\u5c3d CPU \u8d44\u6e90\u3002<\/li>\n\n\n\n<li><strong>\u6d6e\u70b9\u6570\u6bd4\u8f83<\/strong>\uff1a\u7531\u4e8e\u7cbe\u5ea6\u95ee\u9898\uff0c\u907f\u514d\u5728 <code>while<\/code> \u6761\u4ef6\u4e2d\u4f7f\u7528 <code>==<\/code> \u6bd4\u8f83\u6d6e\u70b9\u6570\uff0c\u5e94\u4f7f\u7528 <code>math.isclose()<\/code> \u6216 <code>&lt;<\/code> \/ <code>><\/code>\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\">\u56db\u3001 \u5faa\u73af\u63a7\u5236\u8bed\u53e5\uff1a<code>break<\/code>, <code>continue<\/code>, <code>pass<\/code> \u4e0e <code>else<\/code><\/h3>\n\n\n\n<h4 class=\"wp-block-heading\">1. <code>break<\/code>\uff1a\u7acb\u5373\u7ec8\u6b62\u6574\u4e2a\u5faa\u73af<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u8df3\u51fa\u5f53\u524d\u6240\u5728\u7684\u6700\u5185\u5c42\u5faa\u73af\uff0c\u7ee7\u7eed\u6267\u884c\u5faa\u73af\u4e4b\u540e\u7684\u4ee3\u7801\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><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\">for i in range(10):\n    if i == 5:\n        break  # \u5f53 i \u7b49\u4e8e 5 \u65f6\uff0c\u76f4\u63a5\u8df3\u51fa\u5faa\u73af\n    print(i)   # \u8f93\u51fa: 0, 1, 2, 3, 4<\/code><\/pre><\/div><\/div>\n\n\n\n<h4 class=\"wp-block-heading\">2. <code>continue<\/code>\uff1a\u8df3\u8fc7\u672c\u6b21\u5faa\u73af\u7684\u5269\u4f59\u90e8\u5206<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u7acb\u5373\u7ed3\u675f\u5f53\u524d\u8fed\u4ee3\uff0c\u76f4\u63a5\u8fdb\u5165\u4e0b\u4e00\u6b21\u5faa\u73af\u7684\u5224\u65ad\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><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\">for i in range(5):\n    if i == 2:\n        continue  # \u8df3\u8fc7 i=2 \u7684\u8fd9\u6b21\u8fed\u4ee3\n    print(i)      # \u8f93\u51fa: 0, 1, 3, 4<\/code><\/pre><\/div><\/div>\n\n\n\n<h4 class=\"wp-block-heading\">3. <code>pass<\/code>\uff1a\u7a7a\u64cd\u4f5c\u5360\u4f4d\u7b26<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u5f53\u8bed\u6cd5\u4e0a\u9700\u8981\u4e00\u6761\u8bed\u53e5\uff0c\u4f46\u903b\u8f91\u4e0a\u4e0d\u9700\u8981\u6267\u884c\u4efb\u4f55\u64cd\u4f5c\u65f6\u4f7f\u7528\uff08\u5e38\u7528\u4e8e\u6784\u5efa\u4ee3\u7801\u9aa8\u67b6\uff09\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><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\">for item in data:\n    if item is None:\n        pass  # TODO: \u7a0d\u540e\u5904\u7406\u7a7a\u503c\n    else:\n        process(item)<\/code><\/pre><\/div><\/div>\n\n\n\n<h4 class=\"wp-block-heading\">4. \ud83c\udf1f Python \u72ec\u6709\u7279\u6027\uff1a\u5faa\u73af\u7684 <code>else<\/code> \u5b50\u53e5<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u662f Python \u4e2d\u6781\u5177\u7279\u8272\u4e14\u5e38\u88ab\u8bef\u89e3\u7684\u7279\u6027\u3002<code>for...else<\/code> \u6216 <code>while...else<\/code> \u4e2d\u7684 <code>else<\/code> \u5757<strong>\u4ec5\u5728\u5faa\u73af\u6b63\u5e38\u5b8c\u6210\uff08\u5373\u6ca1\u6709\u88ab <code>break<\/code> \u8bed\u53e5\u6253\u65ad\uff09\u65f6\u624d\u4f1a\u6267\u884c<\/strong>\u3002\u5982\u679c\u5faa\u73af\u662f\u56e0\u4e3a <code>break<\/code> \u9000\u51fa\u7684\uff0c<code>else<\/code> \u5757\u5c06\u88ab\u8df3\u8fc7\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u7ecf\u5178\u5e94\u7528\u573a\u666f\uff1a\u641c\u7d22\u4e0e\u9a8c\u8bc1<\/strong><\/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\"># \u573a\u666f\uff1a\u5728\u5217\u8868\u4e2d\u67e5\u627e\u7d20\u6570\nnumbers = [4, 6, 8, 9, 11]\n\nfor n in numbers:\n    for i in range(2, n):\n        if n % i == 0:\n            print(f&quot;{n} \u4e0d\u662f\u7d20\u6570&quot;)\n            break  # \u627e\u5230\u56e0\u5b50\uff0c\u6253\u65ad\u5185\u5c42\u5faa\u73af\n    else:\n        # \u53ea\u6709\u5f53\u5185\u5c42\u5faa\u73af\u6ca1\u6709\u88ab break \u6253\u65ad\u65f6\uff08\u5373\u6ca1\u6709\u627e\u5230\u4efb\u4f55\u56e0\u5b50\uff09\uff0c\u624d\u4f1a\u6267\u884c\u8fd9\u91cc\n        print(f&quot;{n} \u662f\u7d20\u6570\uff01&quot;)\n\n# \u8f93\u51fa:\n# 4 \u4e0d\u662f\u7d20\u6570\n# 6 \u4e0d\u662f\u7d20\u6570\n# 8 \u4e0d\u662f\u7d20\u6570\n# 9 \u4e0d\u662f\u7d20\u6570\n# 11 \u662f\u7d20\u6570\uff01<\/code><\/pre><\/div><\/div>\n\n\n\n<p class=\"wp-block-paragraph\"><em>\ud83d\udca1 \u63d0\u793a\uff1a\u53ef\u4ee5\u5c06 <code>for...else<\/code> \u7406\u89e3\u4e3a \u201cfor\u2026no break\u201d\u3002\u8fd9\u79cd\u5199\u6cd5\u907f\u514d\u4e86\u4f7f\u7528\u989d\u5916\u7684\u5e03\u5c14\u6807\u5fd7\u53d8\u91cf\uff08\u5982 <code>found = True<\/code>\uff09\uff0c\u4f7f\u4ee3\u7801\u66f4\u4f18\u96c5\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\">\u4e94\u3001 \u9ad8\u7ea7\u5faa\u73af\u6280\u5de7\u4e0e\u5185\u7f6e\u51fd\u6570 \ud83c\udf1f<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u5faa\u73af\u4e2d\u914d\u5408\u4f7f\u7528\u7279\u5b9a\u7684\u5185\u7f6e\u51fd\u6570\uff0c\u53ef\u4ee5\u5f7b\u5e95\u6d88\u9664\u5bf9\u7d22\u5f15\u7684\u4f9d\u8d56\uff0c\u5199\u51fa\u6781\u5176 Pythonic \u7684\u4ee3\u7801\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">1. <code>enumerate()<\/code>: \u540c\u65f6\u83b7\u53d6\u7d22\u5f15\u548c\u503c<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u6c38\u8fdc\u4e0d\u8981<\/strong>\u4f7f\u7528 <code>for i in range(len(my_list)):<\/code> \u8fd9\u79cd\u53cd\u6a21\u5f0f\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><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\">fruits = [&quot;apple&quot;, &quot;banana&quot;, &quot;cherry&quot;]\n\n# \u2705 \u63a8\u8350\u505a\u6cd5\uff1astart \u53c2\u6570\u53ef\u6307\u5b9a\u7d22\u5f15\u8d77\u59cb\u503c\uff08\u9ed8\u8ba4\u4e3a 0\uff09\nfor index, fruit in enumerate(fruits, start=1):\n    print(f&quot;\u7b2c {index} \u4e2a\u6c34\u679c\u662f {fruit}&quot;)<\/code><\/pre><\/div><\/div>\n\n\n\n<h4 class=\"wp-block-heading\">2. <code>zip()<\/code>: \u5e76\u884c\u904d\u5386\u591a\u4e2a\u53ef\u8fed\u4ee3\u5bf9\u8c61<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u5c06\u591a\u4e2a\u5e8f\u5217\u201c\u62c9\u94fe\u201d\u5f0f\u5730\u7ec4\u5408\u5728\u4e00\u8d77\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><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\">names = [&quot;Alice&quot;, &quot;Bob&quot;, &quot;Charlie&quot;]\nscores = [85, 92, 78]\n\nfor name, score in zip(names, scores):\n    print(f&quot;{name} \u7684\u5f97\u5206\u662f {score}&quot;)\n\n# \ud83c\udf1f Python 3.10+ \u65b0\u7279\u6027\uff1astrict=True\n# \u5982\u679c\u4f20\u5165\u7684\u53ef\u8fed\u4ee3\u5bf9\u8c61\u957f\u5ea6\u4e0d\u4e00\u81f4\uff0czip \u9ed8\u8ba4\u4f1a\u4ee5\u6700\u77ed\u7684\u4e3a\u51c6\u622a\u65ad\u3002\n# \u8bbe\u7f6e strict=True \u540e\uff0c\u957f\u5ea6\u4e0d\u4e00\u81f4\u4f1a\u629b\u51fa ValueError\uff0c\u6709\u52a9\u4e8e\u53ca\u65e9\u53d1\u73b0\u6570\u636e Bug\u3002\nids = [1, 2]\n# zip(names, ids, strict=True)  # \u4f1a\u629b\u51fa ValueError\uff0c\u56e0\u4e3a\u957f\u5ea6 3 != 2<\/code><\/pre><\/div><\/div>\n\n\n\n<h4 class=\"wp-block-heading\">3. <code>reversed()<\/code> \u4e0e <code>sorted()<\/code>: \u6539\u53d8\u904d\u5386\u987a\u5e8f<\/h4>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>reversed(seq)<\/code>: \u8fd4\u56de\u4e00\u4e2a\u53cd\u5411\u8fed\u4ee3\u5668\uff0c<strong>\u4e0d\u4fee\u6539\u539f\u5bf9\u8c61<\/strong>\uff0c\u4e14\u6bd4 <code>seq[::-1]<\/code> \u66f4\u8282\u7701\u5185\u5b58\uff08\u4e0d\u521b\u5efa\u65b0\u5217\u8868\uff09\u3002<\/li>\n\n\n\n<li><code>sorted(seq)<\/code>: \u8fd4\u56de\u4e00\u4e2a\u65b0\u7684\u5df2\u6392\u5e8f\u7684\u5217\u8868\u3002<\/li>\n<\/ul>\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\">nums = [3, 1, 4, 1, 5]\n\n# \u5012\u5e8f\u904d\u5386\nfor n in reversed(nums):\n    print(n)  # 5, 1, 4, 1, 3\n\n# \u6392\u5e8f\u540e\u904d\u5386\nfor n in sorted(nums):\n    print(n)  # 1, 1, 3, 4, 5\n\n# \u5012\u5e8f\u4e14\u6392\u5e8f\u904d\u5386\nfor n in sorted(nums, reverse=True):\n    print(n)  # 5, 4, 3, 1, 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\">\u516d\u3001 \u63a8\u5bfc\u5f0f (Comprehensions)\uff1a\u5faa\u73af\u7684\u7ec8\u6781\u8fdb\u5316<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u63a8\u5bfc\u5f0f\u662f Python \u6700\u5177\u6807\u5fd7\u6027\u7684\u8bed\u6cd5\u7cd6\u3002\u5b83\u5141\u8bb8\u4f60\u7528\u4e00\u884c\u7b80\u6d01\u7684\u4ee3\u7801\uff0c\u57fa\u4e8e\u73b0\u6709\u7684\u53ef\u8fed\u4ee3\u5bf9\u8c61\u6784\u5efa\u65b0\u7684\u5217\u8868\u3001\u5b57\u5178\u6216\u96c6\u5408\u3002\u66f4\u91cd\u8981\u7684\u662f\uff0c<strong>\u63a8\u5bfc\u5f0f\u5728 C \u8bed\u8a00\u5c42\u9762\u8fdb\u884c\u4e86\u4f18\u5316\uff0c\u6267\u884c\u901f\u5ea6\u901a\u5e38\u6bd4\u7b49\u6548\u7684 <code>for<\/code> \u5faa\u73af\u52a0 <code>append()<\/code> \u5feb 20% \u5230 50%<\/strong>\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">1. \u5217\u8868\u63a8\u5bfc\u5f0f (List Comprehension)<\/h4>\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><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\"># \u9700\u6c42\uff1a\u751f\u6210 0-9 \u4e2d\u5076\u6570\u7684\u5e73\u65b9\u5217\u8868\n\n# \u274c \u4f20\u7edf\u5199\u6cd5\nsquares = []\nfor x in range(10):\n    if x % 2 == 0:\n        squares.append(x**2)\n\n# \u2705 \u63a8\u5bfc\u5f0f\u5199\u6cd5 (\u8868\u8fbe\u5f0f + for \u5b50\u53e5 + \u53ef\u9009\u7684 if \u5b50\u53e5)\nsquares = [x**2 for x in range(10) if x % 2 == 0]<\/code><\/pre><\/div><\/div>\n\n\n\n<h4 class=\"wp-block-heading\">2. \u5b57\u5178\u4e0e\u96c6\u5408\u63a8\u5bfc\u5f0f<\/h4>\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\"># \u5b57\u5178\u63a8\u5bfc\u5f0f\uff1a\u5feb\u901f\u53cd\u8f6c\u952e\u503c\u5bf9\noriginal = {&quot;a&quot;: 1, &quot;b&quot;: 2, &quot;c&quot;: 3}\nreversed_dict = {v: k for k, v in original.items()}  # {1: &#039;a&#039;, 2: &#039;b&#039;, 3: &#039;c&#039;}\n\n# \u96c6\u5408\u63a8\u5bfc\u5f0f\uff1a\u81ea\u52a8\u53bb\u91cd\ntext = &quot;hello&quot;\nunique_chars = {char for char in text}  # {&#039;h&#039;, &#039;e&#039;, &#039;l&#039;, &#039;o&#039;}<\/code><\/pre><\/div><\/div>\n\n\n\n<h4 class=\"wp-block-heading\">3. \u5d4c\u5957\u63a8\u5bfc\u5f0f<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u53ef\u4ee5\u5c06\u591a\u5c42 <code>for<\/code> \u5faa\u73af\u538b\u7f29\u4e3a\u4e00\u884c\uff0c\u4f46<strong>\u9700\u4e25\u683c\u63a7\u5236\u590d\u6742\u5ea6\u4ee5\u4fdd\u8bc1\u53ef\u8bfb\u6027<\/strong>\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\"># \u751f\u6210\u5750\u6807\u77e9\u9635 (x, y) \u5176\u4e2d x \u548c y \u90fd\u5728 0-2 \u4e4b\u95f4\ncoords = [(x, y) for x in range(3) for y in range(3)]\n# \u7b49\u4ef7\u4e8e:\n# coords = []\n# for x in range(3):\n#     for y in range(3):\n#         coords.append((x, y))<\/code><\/pre><\/div><\/div>\n\n\n\n<p class=\"wp-block-paragraph\"><em>\u26a0\ufe0f \u6700\u4f73\u5b9e\u8df5<\/em>\uff1a\u5982\u679c\u63a8\u5bfc\u5f0f\u8d85\u8fc7\u4e24\u884c\uff0c\u6216\u8005\u5305\u542b\u590d\u6742\u7684\u903b\u8f91\u5224\u65ad\uff0c\u8bf7\u679c\u65ad\u9000\u56de\u5230\u666e\u901a\u7684 <code>for<\/code> \u5faa\u73af\u3002<strong>\u53ef\u8bfb\u6027\u6c38\u8fdc\u9ad8\u4e8e\u70ab\u6280<\/strong>\u3002<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\u4e03\u3001 \u6807\u51c6\u5e93\u5229\u5668\uff1a<code>itertools<\/code> \u6a21\u5757<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u5f53\u9762\u5bf9\u590d\u6742\u7684\u8fed\u4ee3\u9700\u6c42\u65f6\uff0cPython \u6807\u51c6\u5e93\u4e2d\u7684 <code>itertools<\/code> \u6a21\u5757\u63d0\u4f9b\u4e86\u7528 C \u8bed\u8a00\u7f16\u5199\u7684\u9ad8\u6027\u80fd\u5de5\u5177\uff0c\u662f\u5904\u7406\u5faa\u73af\u7684\u201c\u745e\u58eb\u519b\u5200\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><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><span>19<\/span><span>20<\/span><span>21<\/span><span>22<\/span><span>23<\/span><span>24<\/span><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\">import itertools\n\n# 1. itertools.count(start, step): \u521b\u5efa\u65e0\u9650\u9012\u589e\u7684\u8ba1\u6570\u5668\n# \u5e38\u7528\u4e8e\u4e3a\u6ca1\u6709\u7d22\u5f15\u7684\u6d41\u6570\u636e\u6dfb\u52a0\u5e8f\u53f7\nfor i, val in zip(itertools.count(1), [&quot;a&quot;, &quot;b&quot;, &quot;c&quot;]):\n    print(f&quot;{i}: {val}&quot;)  # 1: a, 2: b, 3: c\n\n# 2. itertools.cycle(iterable): \u65e0\u9650\u5faa\u73af\u904d\u5386\u4e00\u4e2a\u5e8f\u5217\n# \u5e38\u7528\u4e8e\u8f6e\u8be2\u8c03\u5ea6 (Round-Robin)\ncolors = itertools.cycle([&quot;red&quot;, &quot;green&quot;, &quot;blue&quot;])\nfor _ in range(5):\n    print(next(colors))  # red, green, blue, red, green\n\n# 3. itertools.chain(*iterables): \u5c06\u591a\u4e2a\u53ef\u8fed\u4ee3\u5bf9\u8c61\u65e0\u7f1d\u8fde\u63a5\u6210\u4e00\u4e2a\nlist1 = [1, 2]\nlist2 = [3, 4]\nfor item in itertools.chain(list1, list2):\n    print(item)  # 1, 2, 3, 4 (\u6bd4 list1 + list2 \u66f4\u7701\u5185\u5b58\uff0c\u56e0\u4e3a\u4e0d\u521b\u5efa\u65b0\u5217\u8868)\n\n# 4. itertools.product(*iterables, repeat=1): \u8ba1\u7b97\u7b1b\u5361\u5c14\u79ef\n# \u5b8c\u7f8e\u66ff\u4ee3\u6df1\u5c42\u5d4c\u5957\u7684 for \u5faa\u73af\nfor x, y in itertools.product([1, 2], [&#039;a&#039;, &#039;b&#039;]):\n    print(f&quot;({x}, {y})&quot;)  \n    # (1, &#039;a&#039;), (1, &#039;b&#039;), (2, &#039;a&#039;), (2, &#039;b&#039;)<\/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\">\u516b\u3001 \u6027\u80fd\u5206\u6790\u4e0e\u6838\u5fc3\u907f\u5751\u6307\u5357 (Big-O \u590d\u6742\u5ea6)<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u7f16\u5199\u5faa\u73af\u65f6\uff0c\u5fae\u5c0f\u7684\u4e60\u60ef\u5dee\u5f02\u53ef\u80fd\u5bfc\u81f4\u5de8\u5927\u7684\u6027\u80fd\u9e3f\u6c9f\u3002\u4ee5\u4e0b\u662f\u5fc5\u987b\u9075\u5b88\u7684\u6700\u4f73\u5b9e\u8df5\uff1a<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">1. \u274c \u7edd\u5bf9\u4e0d\u8981\u5728\u5faa\u73af\u4e2d\u4fee\u6539\u6b63\u5728\u904d\u5386\u7684\u53ef\u53d8\u5e8f\u5217<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u904d\u5386\u5217\u8868\u6216\u5b57\u5178\u65f6\u76f4\u63a5\u6dfb\u52a0\u6216\u5220\u9664\u5143\u7d20\uff0c\u4f1a\u5bfc\u81f4\u8fed\u4ee3\u5668\u72b6\u6001\u6df7\u4e71\uff0c\u5f15\u53d1 <code>RuntimeError<\/code> \u6216\u9759\u9ed8\u7684\u903b\u8f91\u9519\u8bef\uff08\u8df3\u8fc7\u5143\u7d20\uff09\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><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\">nums = [1, 2, 3, 4, 5]\n\n# \u274c \u9519\u8bef\uff1a\u8fd0\u884c\u65f6\u4f1a\u8df3\u8fc7\u5143\u7d20\u6216\u62a5\u9519\nfor n in nums:\n    if n % 2 == 0:\n        nums.remove(n) \n\n# \u2705 \u6b63\u786e\u505a\u6cd5 1\uff1a\u904d\u5386\u526f\u672c\nfor n in nums[:]:  # nums[:] \u521b\u5efa\u4e86\u6d45\u62f7\u8d1d\n    if n % 2 == 0:\n        nums.remove(n)\n\n# \u2705 \u6b63\u786e\u505a\u6cd5 2 (\u66f4\u63a8\u8350)\uff1a\u4f7f\u7528\u5217\u8868\u63a8\u5bfc\u5f0f\u91cd\u5efa\nnums = [n for n in nums if n % 2 != 0]<\/code><\/pre><\/div><\/div>\n\n\n\n<h4 class=\"wp-block-heading\">2. \u274c \u907f\u514d\u5728\u5faa\u73af\u5185\u90e8\u8fdb\u884c $O(N)$ \u7684\u6602\u8d35\u64cd\u4f5c<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u5c06\u65f6\u95f4\u590d\u6742\u5ea6\u9ad8\u7684\u64cd\u4f5c\u79fb\u51fa\u5faa\u73af\u4f53\uff0c\u6216\u9009\u62e9\u5408\u9002\u7684\u6570\u636e\u7ed3\u6784\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><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\"># \u274c \u53cd\u6a21\u5f0f\uff1a\u5728\u5faa\u73af\u5934\u90e8\u63d2\u5165\uff0c\u6bcf\u6b21\u90fd\u662f O(N)\uff0c\u603b\u4f53 O(N\u00b2)\nresult = []\nfor i in range(10000):\n    result.insert(0, i) \n\n# \u2705 \u4f18\u5316 1\uff1a\u5c3e\u90e8\u8ffd\u52a0\uff0c\u6700\u540e\u53cd\u8f6c (\u603b\u4f53 O(N))\nresult = []\nfor i in range(10000):\n    result.append(i)\nresult.reverse()\n\n# \u2705 \u4f18\u5316 2\uff1a\u4f7f\u7528 collections.deque (\u53cc\u7aef\u961f\u5217\uff0c\u5934\u90e8\u63d2\u5165\u4e3a O(1))\nfrom collections import deque\nresult = deque()\nfor i in range(10000):\n    result.appendleft(i)<\/code><\/pre><\/div><\/div>\n\n\n\n<h4 class=\"wp-block-heading\">3. \u274c \u907f\u514d\u5728\u5faa\u73af\u4e2d\u4f7f\u7528 <code>+=<\/code> \u62fc\u63a5\u5b57\u7b26\u4e32<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u7531\u4e8e\u5b57\u7b26\u4e32\u662f\u4e0d\u53ef\u53d8\u7684\uff0c\u6bcf\u6b21 <code>+=<\/code> \u90fd\u4f1a\u521b\u5efa\u4e00\u4e2a\u65b0\u7684\u5b57\u7b26\u4e32\u5bf9\u8c61\u5e76\u590d\u5236\u6240\u6709\u5b57\u7b26\uff0c\u5bfc\u81f4 $O(N^2)$ \u7684\u65f6\u95f4\u590d\u6742\u5ea6\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\"># \u274c \u4f4e\u6548\ntext = &quot;&quot;\nfor word in words:\n    text += word + &quot; &quot;\n\n# \u2705 \u9ad8\u6548\uff1a\u4f7f\u7528 str.join() (O(N))\ntext = &quot; &quot;.join(words)<\/code><\/pre><\/div><\/div>\n\n\n\n<h4 class=\"wp-block-heading\">4. \ud83d\udca1 \u5c40\u90e8\u53d8\u91cf\u67e5\u627e\u5feb\u4e8e\u5168\u5c40\/\u5185\u7f6e\u53d8\u91cf<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u6781\u5ea6\u8ffd\u6c42\u6027\u80fd\u7684\u5faa\u73af\uff08\u5982\u767e\u4e07\u6b21\u8fed\u4ee3\uff09\u4e2d\uff0c\u5c06\u9891\u7e41\u8c03\u7528\u7684\u51fd\u6570\u6216\u5c5e\u6027\u7ed1\u5b9a\u5230\u5c40\u90e8\u53d8\u91cf\uff0c\u53ef\u4ee5\u8282\u7701\u540d\u79f0\u67e5\u627e\u7684\u5f00\u9500\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><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\">import math\n\n# \u8f83\u6162\uff1a\u6bcf\u6b21\u5faa\u73af\u90fd\u8981\u5728\u5168\u5c40\/\u5185\u7f6e\u547d\u540d\u7a7a\u95f4\u4e2d\u67e5\u627e &#039;math.sqrt&#039;\nfor i in range(1000000):\n    x = math.sqrt(i)\n\n# \u8f83\u5feb\uff1a\u5c06\u51fd\u6570\u5f15\u7528\u7ed1\u5b9a\u5230\u5c40\u90e8\u53d8\u91cf\nsqrt = math.sqrt\nfor i in range(1000000):\n    x = sqrt(i)<\/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\">\u4e5d\u3001 \u603b\u7ed3<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Python 3 \u7684\u5faa\u73af\u8bed\u53e5\u4e0d\u4ec5\u4ec5\u662f\u91cd\u590d\u6267\u884c\u4ee3\u7801\u7684\u5de5\u5177\uff0c\u5b83\u662f\u4e00\u5957\u4e0e\u8bed\u8a00\u5e95\u5c42\u6570\u636e\u6a21\u578b\uff08\u8fed\u4ee3\u5668\u534f\u8bae\uff09\u6df1\u5ea6\u7ed1\u5b9a\u7684\u4f18\u96c5\u673a\u5236\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u9996\u9009 <code>for<\/code> \u5faa\u73af<\/strong>\uff1a\u56e0\u4e3a\u5b83\u76f4\u63a5\u8868\u8fbe\u201c\u5bf9\u96c6\u5408\u4e2d\u7684\u6bcf\u4e2a\u5143\u7d20\u6267\u884c\u64cd\u4f5c\u201d\u7684\u610f\u56fe\uff0c\u4e14\u907f\u514d\u4e86\u7d22\u5f15\u7ba1\u7406\u7684\u7e41\u7410\u4e0e\u8d8a\u754c\u98ce\u9669\u3002<\/li>\n\n\n\n<li><strong>\u5584\u7528\u9ad8\u7ea7\u5185\u7f6e\u51fd\u6570<\/strong>\uff1a<code>enumerate<\/code>\u3001<code>zip<\/code> \u548c <code>reversed<\/code> \u80fd\u8ba9\u4f60\u7684\u5faa\u73af\u4ee3\u7801\u6446\u8131\u7d22\u5f15\uff0c\u53d8\u5f97\u58f0\u660e\u5f0f\u4e14\u6613\u8bfb\u3002<\/li>\n\n\n\n<li><strong>\u62e5\u62b1\u63a8\u5bfc\u5f0f<\/strong>\uff1a\u5728\u903b\u8f91\u7b80\u5355\u65f6\uff0c\u7528\u63a8\u5bfc\u5f0f\u66ff\u4ee3 <code>for + append<\/code>\uff0c\u83b7\u5f97\u66f4\u597d\u7684\u6027\u80fd\u548c\u66f4\u7b80\u6d01\u7684\u8bed\u6cd5\u3002<\/li>\n\n\n\n<li><strong>\u638c\u63e1 <code>for...else<\/code><\/strong>\uff1a\u5728\u641c\u7d22\u548c\u9a8c\u8bc1\u573a\u666f\u4e2d\uff0c\u5b83\u662f\u6d88\u9664\u5197\u4f59\u6807\u5fd7\u53d8\u91cf\u7684\u5229\u5668\u3002<\/li>\n\n\n\n<li><strong>\u8b66\u60d5\u6027\u80fd\u9677\u9631<\/strong>\uff1a\u907f\u514d\u5728\u5faa\u73af\u4e2d\u4fee\u6539\u539f\u5e8f\u5217\u3001\u907f\u514d\u5b57\u7b26\u4e32 <code>+=<\/code> \u62fc\u63a5\u3001\u8b66\u60d5 $O(N^2)$ \u7684\u9690\u85cf\u64cd\u4f5c\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u5f53\u4f60\u80fd\u591f\u719f\u7ec3\u5730\u5728 <code>for<\/code> \u5faa\u73af\u3001\u63a8\u5bfc\u5f0f\u548c <code>itertools<\/code> \u4e4b\u95f4\u505a\u51fa\u6700\u5408\u9002\u7684\u9009\u62e9\u65f6\uff0c\u4f60\u7684 Python \u4ee3\u7801\u5c06\u771f\u6b63\u5c55\u73b0\u51fa\u7b80\u6d01\u3001\u9ad8\u6548\u4e0e\u5f3a\u5927\u7684\u201cPythonic\u201d\u9b45\u529b\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5982\u679c\u4f60\u5bf9\u7279\u5b9a\u573a\u666f\u4e0b\u7684\u5faa\u73af\u4f18\u5316\uff08\u5982\u591a\u7ebf\u7a0b\/\u5f02\u6b65\u5faa\u73af <code>async for<\/code>\uff09\uff0c\u6216 <code>itertools<\/code> \u4e2d\u66f4\u590d\u6742\u7684\u7ec4\u5408\u7b97\u6cd5\u6709\u7591\u95ee\uff0c\u6b22\u8fce\u968f\u65f6\u6df1\u5165\u63a2\u8ba8\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5728 Python 3 \u4e2d\uff0c\u5faa\u73af\u8bed\u53e5 (Loop S&#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-62","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\/62","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=62"}],"version-history":[{"count":1,"href":"https:\/\/www.52runoob.com\/index.php\/wp-json\/wp\/v2\/posts\/62\/revisions"}],"predecessor-version":[{"id":63,"href":"https:\/\/www.52runoob.com\/index.php\/wp-json\/wp\/v2\/posts\/62\/revisions\/63"}],"wp:attachment":[{"href":"https:\/\/www.52runoob.com\/index.php\/wp-json\/wp\/v2\/media?parent=62"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.52runoob.com\/index.php\/wp-json\/wp\/v2\/categories?post=62"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.52runoob.com\/index.php\/wp-json\/wp\/v2\/tags?post=62"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}