{"id":95,"date":"2026-06-13T19:07:13","date_gmt":"2026-06-13T11:07:13","guid":{"rendered":"https:\/\/www.52runoob.com\/?p=95"},"modified":"2026-06-13T19:07:13","modified_gmt":"2026-06-13T11:07:13","slug":"python3-%e5%ad%97%e5%85%b8-2","status":"publish","type":"post","link":"https:\/\/www.52runoob.com\/index.php\/2026\/06\/13\/python3-%e5%ad%97%e5%85%b8-2\/","title":{"rendered":"Python3\u00a0\u5b57\u5178"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">\u5728 Python 3 \u4e2d\uff0c<strong>\u5b57\u5178\uff08Dictionary\uff09<\/strong> \u662f\u6700\u5f3a\u5927\u3001\u6700\u5e38\u7528\u7684\u6570\u636e\u7ed3\u6784\u4e4b\u4e00\u3002\u5b83\u901a\u8fc7<strong>\u952e\u503c\u5bf9\uff08Key-Value pairs\uff09<\/strong> \u6765\u5b58\u50a8\u6570\u636e\uff0c\u5e95\u5c42\u57fa\u4e8e<strong>\u54c8\u5e0c\u8868\uff08Hash Table\uff09<\/strong> \u5b9e\u73b0\uff0c\u8fd9\u4f7f\u5f97\u5b83\u7684\u67e5\u627e\u3001\u63d2\u5165\u548c\u5220\u9664\u64cd\u4f5c\u5e73\u5747\u65f6\u95f4\u590d\u6742\u5ea6\u90fd\u8fbe\u5230\u4e86\u60ca\u4eba\u7684 <strong>O(1)<\/strong>\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><em>\ud83d\udca1 <strong>\u91cd\u8981\u7279\u6027<\/strong>\uff1a\u4ece Python 3.7 \u5f00\u59cb\uff0c\u5b57\u5178<strong>\u4e25\u683c\u4fdd\u8bc1\u4fdd\u6301\u5143\u7d20\u7684\u63d2\u5165\u987a\u5e8f<\/strong>\u3002\u8fd9\u662f\u73b0\u4ee3 Python \u7684\u4e00\u4e2a\u91cd\u5927\u6539\u8fdb\u3002<\/em><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e0b\u9762\u6211\u5c06\u4ece<strong>\u57fa\u7840\u64cd\u4f5c<\/strong>\u3001<strong>\u9ad8\u7ea7\u6280\u5de7<\/strong>\u3001<strong>\u73b0\u4ee3\u8bed\u6cd5<\/strong>\u5230<strong>\u5e38\u89c1\u9677\u9631<\/strong>\uff0c\u4e3a\u4f60\u5168\u9762\u89e3\u6790 Python 3 \u5b57\u5178\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 \u521b\u5efa\u4e0e\u521d\u59cb\u5316\u5b57\u5178<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u6709\u591a\u79cd\u65b9\u5f0f\u53ef\u4ee5\u521b\u5efa\u5b57\u5178\uff0c\u9002\u7528\u4e8e\u4e0d\u540c\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><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\"># 1. \u5b57\u9762\u91cf\u521b\u5efa (\u6700\u5e38\u7528\u3001\u6700\u76f4\u89c2)\nuser = {&quot;name&quot;: &quot;Alice&quot;, &quot;age&quot;: 25, &quot;city&quot;: &quot;Beijing&quot;}\n\n# 2. \u4f7f\u7528 dict() \u6784\u9020\u51fd\u6570\n# \u65b9\u5f0f A: \u4f20\u5165\u5173\u952e\u5b57\u53c2\u6570 (\u952e\u5fc5\u987b\u662f\u5408\u6cd5\u7684\u6807\u8bc6\u7b26\uff0c\u5373\u5b57\u7b26\u4e32\u4e14\u4e0d\u80fd\u4ee5\u6570\u5b57\u5f00\u5934)\nconfig = dict(host=&quot;localhost&quot;, port=8080, debug=True)\n\n# \u65b9\u5f0f B: \u4f20\u5165\u5305\u542b\u952e\u503c\u5bf9\u7684\u5143\u7ec4\u5217\u8868\nitems = dict([(&quot;name&quot;, &quot;Bob&quot;), (&quot;age&quot;, 30)])\n\n# 3. \u4f7f\u7528 fromkeys() \u5feb\u901f\u521b\u5efa\u5177\u6709\u76f8\u540c\u9ed8\u8ba4\u503c\u7684\u5b57\u5178\nkeys = [&quot;a&quot;, &quot;b&quot;, &quot;c&quot;]\ndefault_dict = dict.fromkeys(keys, 0) \nprint(default_dict)  # \u8f93\u51fa: {&#039;a&#039;: 0, &#039;b&#039;: 0, &#039;c&#039;: 0}<\/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\">\u4e8c\u3001 \u6838\u5fc3\u64cd\u4f5c\uff1a\u589e\u3001\u5220\u3001\u6539\u3001\u67e5<\/h3>\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><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\">my_dict = {&quot;apple&quot;: 3, &quot;banana&quot;: 5}\n\n# 1. \u67e5 (\u8bbf\u95ee)\nprint(my_dict[&quot;apple&quot;])  # \u8f93\u51fa: 3\n# print(my_dict[&quot;orange&quot;]) # \u274c \u4f1a\u629b\u51fa KeyError: &#039;orange&#039;\n\n# \u2705 \u5b89\u5168\u8bbf\u95ee\uff1a\u4f7f\u7528 .get()\uff0c\u627e\u4e0d\u5230\u65f6\u8fd4\u56de None \u6216\u6307\u5b9a\u7684\u9ed8\u8ba4\u503c\nprint(my_dict.get(&quot;orange&quot;, 0))  # \u8f93\u51fa: 0 (\u5f3a\u70c8\u63a8\u8350\u8fd9\u79cd\u505a\u6cd5)\n\n# 2. \u6539 (\u4fee\u6539)\nmy_dict[&quot;apple&quot;] = 10  # \u952e\u5b58\u5728\uff0c\u5219\u66f4\u65b0\u503c\n\n# 3. \u589e (\u6dfb\u52a0)\nmy_dict[&quot;orange&quot;] = 8  # \u952e\u4e0d\u5b58\u5728\uff0c\u5219\u6dfb\u52a0\u65b0\u952e\u503c\u5bf9\n\n# 4. \u5220 (\u5220\u9664)\ndel my_dict[&quot;banana&quot;]           # \u5220\u9664\u6307\u5b9a\u952e\uff0c\u4e0d\u5b58\u5728\u4f1a\u62a5 KeyError\nvalue = my_dict.pop(&quot;apple&quot;)    # \u5220\u9664\u5e76\u8fd4\u56de\u8be5\u952e\u7684\u503c\uff0c\u53ef\u5e26\u9ed8\u8ba4\u503c\u9632\u6b62\u62a5\u9519\nlast_item = my_dict.popitem()   # \u5220\u9664\u5e76\u8fd4\u56de**\u6700\u540e\u63d2\u5165**\u7684\u952e\u503c\u5bf9 (Python 3.7+)\nmy_dict.clear()                 # \u6e05\u7a7a\u5b57\u5178<\/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 \u904d\u5386\u5b57\u5178\u7684 3 \u79cd\u6807\u51c6\u59ff\u52bf<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u5faa\u73af\u4e2d\u5904\u7406\u5b57\u5178\u65f6\uff0cPython \u63d0\u4f9b\u4e86\u6781\u5176\u4f18\u96c5\u7684\u65b9\u6cd5\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\">scores = {&quot;Alice&quot;: 95, &quot;Bob&quot;: 88, &quot;Charlie&quot;: 92}\n\n# 1. \u904d\u5386\u952e (\u9ed8\u8ba4\u884c\u4e3a\uff0c\u7b49\u540c\u4e8e scores.keys())\nfor key in scores:\n    print(key)\n\n# 2. \u904d\u5386\u503c\nfor value in scores.values():\n    print(value)\n\n# 3. \u904d\u5386\u952e\u503c\u5bf9 (\u6700\u5e38\u7528\uff0c\u5229\u7528\u5143\u7ec4\u89e3\u5305)\nfor name, score in scores.items():\n    print(f&quot;{name} \u7684\u5206\u6570\u662f {score}&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\">\u56db\u3001 \u9ad8\u7ea7\u6280\u5de7\u4e0e\u73b0\u4ee3\u8bed\u6cd5 (Python 3.5+)<\/h3>\n\n\n\n<h4 class=\"wp-block-heading\">1. \u5b57\u5178\u5408\u5e76\u4e0e\u66f4\u65b0<\/h4>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong><code>.update()<\/code><\/strong>\uff1a\u5c31\u5730\u66f4\u65b0\u5b57\u5178\uff08\u4fee\u6539\u539f\u5b57\u5178\uff09\u3002<br><code>python dict1 = {\"a\": 1, \"b\": 2} dict2 = {\"b\": 3, \"c\": 4} dict1.update(dict2) print(dict1) # \u8f93\u51fa: {'a': 1, 'b': 3, 'c': 4} (b \u7684\u503c\u88ab\u8986\u76d6)<\/code><\/li>\n\n\n\n<li><strong><code>|<\/code> \u548c <code>|=<\/code> \u8fd0\u7b97\u7b26 (Python 3.9+ \u65b0\u589e)<\/strong>\uff1a\u66f4\u4f18\u96c5\u7684\u5408\u5e76\u65b9\u5f0f\u3002 <code>dict1 = {\"a\": 1, \"b\": 2} dict2 = {\"b\": 3, \"c\": 4} # | \u521b\u5efa\u65b0\u5b57\u5178\uff0c\u4e0d\u4fee\u6539\u539f\u5b57\u5178 merged = dict1 | dict2 # {'a': 1, 'b': 3, 'c': 4} # |= \u5c31\u5730\u66f4\u65b0 dict1 dict1 |= dict2<\/code><\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\">2. \u5b57\u5178\u89e3\u5305 (<code>**<\/code>)<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u51fd\u6570\u4f20\u53c2\u6216\u5408\u5e76\u5b57\u5178\u65f6\u975e\u5e38\u6709\u7528\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><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\">defaults = {&quot;host&quot;: &quot;localhost&quot;, &quot;port&quot;: 80}\noverrides = {&quot;port&quot;: 8080, &quot;debug&quot;: True}\n\n# \u5408\u5e76\u5b57\u5178 (Python 3.5+)\nconfig = {**defaults, **overrides}\nprint(config)  # \u8f93\u51fa: {&#039;host&#039;: &#039;localhost&#039;, &#039;port&#039;: 8080, &#039;debug&#039;: True}<\/code><\/pre><\/div><\/div>\n\n\n\n<h4 class=\"wp-block-heading\">3. <code>setdefault()<\/code>\uff1a\u4f18\u96c5\u7684\u201c\u5982\u679c\u4e0d\u5b58\u5728\u5219\u8bbe\u7f6e\u201d<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u5f53\u4f60\u9700\u8981\u521d\u59cb\u5316\u5b57\u5178\u4e2d\u7684\u5217\u8868\u6216\u96c6\u5408\u65f6\uff0c\u8fd9\u4e2a\u65b9\u6cd5\u662f\u795e\u5668\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\"># \u573a\u666f\uff1a\u6309\u7c7b\u522b\u5206\u7ec4\u6570\u636e\ndata = [(&quot;fruit&quot;, &quot;apple&quot;), (&quot;fruit&quot;, &quot;banana&quot;), (&quot;color&quot;, &quot;red&quot;)]\ngroups = {}\n\nfor category, item in data:\n    # \u5982\u679c category \u4e0d\u5b58\u5728\uff0c\u5148\u8bbe\u4e3a\u7a7a\u5217\u8868 []\uff0c\u7136\u540e append\n    groups.setdefault(category, []).append(item)\n\nprint(groups)  \n# \u8f93\u51fa: {&#039;fruit&#039;: [&#039;apple&#039;, &#039;banana&#039;], &#039;color&#039;: [&#039;red&#039;]}<\/code><\/pre><\/div><\/div>\n\n\n\n<p class=\"wp-block-paragraph\"><em>(\u6ce8\uff1a\u5bf9\u4e8e\u590d\u6742\u7684\u5206\u7ec4\u573a\u666f\uff0c\u524d\u6587\u63d0\u5230\u7684 <code>collections.defaultdict<\/code> \u662f\u66f4\u597d\u7684\u9009\u62e9)<\/em><\/p>\n\n\n\n<h4 class=\"wp-block-heading\">4. \u5b57\u5178\u63a8\u5bfc\u5f0f (Dictionary Comprehension)<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e0e\u5217\u8868\u63a8\u5bfc\u5f0f\u7c7b\u4f3c\uff0c\u7528\u4e8e\u5feb\u901f\u751f\u6210\u6216\u8f6c\u6362\u5b57\u5178\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\">numbers = [1, 2, 3, 4]\n\n# \u751f\u6210 {\u6570\u5b57: \u6570\u5b57\u7684\u5e73\u65b9} \u7684\u5b57\u5178\nsquares_dict = {x: x**2 for x in numbers if x % 2 == 0}\nprint(squares_dict)  # \u8f93\u51fa: {2: 4, 4: 16}\n\n# \u7ffb\u8f6c\u5b57\u5178\u7684\u952e\u548c\u503c (\u524d\u63d0\u662f\u503c\u662f\u53ef\u54c8\u5e0c\u7684\u4e14\u552f\u4e00)\noriginal = {&quot;a&quot;: 1, &quot;b&quot;: 2}\nflipped = {v: k for k, v in original.items()}\nprint(flipped)  # \u8f93\u51fa: {1: &#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\">\u4e94\u3001 \u26a0\ufe0f \u5e38\u89c1\u9677\u9631\u4e0e\u6700\u4f73\u5b9e\u8df5<\/h3>\n\n\n\n<h4 class=\"wp-block-heading\">\u9677\u9631 1\uff1a\u952e\u5fc5\u987b\u662f\u201c\u53ef\u54c8\u5e0c\u7684\u201d (Hashable)<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u5b57\u5178\u7684\u952e\u5fc5\u987b\u662f\u4e0d\u53ef\u53d8\u7c7b\u578b\uff08\u5982\u5b57\u7b26\u4e32\u3001\u6570\u5b57\u3001\u5143\u7ec4\uff09\u3002<strong>\u4e0d\u80fd<\/strong>\u4f7f\u7528\u5217\u8868\u3001\u5b57\u5178\u6216\u96c6\u5408\u4f5c\u4e3a\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><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\"># \u274c TypeError: unhashable type: &#039;list&#039;\nbad_dict = {[1, 2]: &quot;value&quot;}\n\n# \u2705 \u6b63\u786e\u505a\u6cd5\uff1a\u4f7f\u7528\u5143\u7ec4\u4f5c\u4e3a\u952e\ngood_dict = {(1, 2): &quot;value&quot;}<\/code><\/pre><\/div><\/div>\n\n\n\n<p class=\"wp-block-paragraph\"><em>(\u503c\u53ef\u4ee5\u662f\u4efb\u4f55\u7c7b\u578b\uff0c\u5305\u62ec\u5217\u8868\u6216\u5b57\u5178)<\/em><\/p>\n\n\n\n<h4 class=\"wp-block-heading\">\u9677\u9631 2\uff1a\u5728\u904d\u5386\u5b57\u5178\u65f6\u4fee\u6539\u5b83\u7684\u5927\u5c0f<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728 <code>for<\/code> \u5faa\u73af\u904d\u5386\u5b57\u5178\u65f6\uff0c\u5982\u679c\u6dfb\u52a0\u6216\u5220\u9664\u952e\uff0c\u4f1a\u5bfc\u81f4 <code>RuntimeError: dictionary changed size during iteration<\/code>\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\">my_dict = {&quot;a&quot;: 1, &quot;b&quot;: 2, &quot;c&quot;: 3}\n\n# \u274c \u9519\u8bef\uff1a\u904d\u5386\u65f6\u5220\u9664\n# for k in my_dict:\n#     if k == &quot;b&quot;:\n#         del my_dict[k]\n\n# \u2705 \u6b63\u786e\u505a\u6cd5 1\uff1a\u904d\u5386\u5b57\u5178\u952e\u7684\u526f\u672c (list)\nfor k in list(my_dict.keys()):\n    if k == &quot;b&quot;:\n        del my_dict[k]\n\n# \u2705 \u6b63\u786e\u505a\u6cd5 2\uff1a\u4f7f\u7528\u5b57\u5178\u63a8\u5bfc\u5f0f\u751f\u6210\u65b0\u5b57\u5178\nmy_dict = {k: v for k, v in my_dict.items() if k != &quot;b&quot;}<\/code><\/pre><\/div><\/div>\n\n\n\n<h4 class=\"wp-block-heading\">\u9677\u9631 3\uff1a\u8bef\u4ee5\u4e3a\u5b57\u5178\u662f\u201c\u6309\u5b57\u6bcd\u987a\u5e8f\u201d\u6392\u5e8f\u7684<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">Python 3.7+ \u4fdd\u8bc1\u7684\u662f<strong>\u63d2\u5165\u987a\u5e8f<\/strong>\uff0c\u800c\u4e0d\u662f\u6309\u952e\u7684\u5b57\u6bcd\u6216\u6570\u5b57\u5927\u5c0f\u6392\u5e8f\u3002\u5982\u679c\u9700\u8981\u6392\u5e8f\uff0c\u5fc5\u987b\u663e\u5f0f\u4f7f\u7528 <code>sorted()<\/code>\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\">d = {&quot;z&quot;: 1, &quot;a&quot;: 2, &quot;m&quot;: 3}\n# \u6309\u952e\u6392\u5e8f\nsorted_by_key = dict(sorted(d.items())) \nprint(sorted_by_key)  # \u8f93\u51fa: {&#039;a&#039;: 2, &#039;m&#039;: 3, &#039;z&#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\">\u516d\u3001 \u603b\u7ed3\uff1a\u4f55\u65f6\u4f7f\u7528\u5b57\u5178\uff1f<\/h3>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th class=\"has-text-align-left\" data-align=\"left\">\u4f60\u7684\u9700\u6c42<\/th><th class=\"has-text-align-left\" data-align=\"left\">\u63a8\u8350\u6570\u636e\u7ed3\u6784<\/th><\/tr><\/thead><tbody><tr><td class=\"has-text-align-left\" data-align=\"left\">\u9700\u8981\u901a\u8fc7<strong>\u540d\u79f0\/\u6807\u8bc6\u7b26<\/strong>\u5feb\u901f\u67e5\u627e\u5bf9\u5e94\u7684\u6570\u636e<\/td><td class=\"has-text-align-left\" data-align=\"left\"><strong><code>dict<\/code><\/strong> (\u4f8b\u5982\uff1a\u901a\u8fc7\u7528\u6237 ID \u67e5\u7528\u6237\u4fe1\u606f)<\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\">\u9700\u8981\u8bb0\u5f55\u914d\u7f6e\u9879\u3001\u53c2\u6570\u6216\u5177\u6709\u660e\u786e\u5c5e\u6027\u7684\u5b9e\u4f53<\/td><td class=\"has-text-align-left\" data-align=\"left\"><strong><code>dict<\/code><\/strong> (\u6216 Python 3.7+ \u7684 <code>@dataclass<\/code>)<\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\">\u9700\u8981\u7edf\u8ba1\u5143\u7d20\u51fa\u73b0\u6b21\u6570<\/td><td class=\"has-text-align-left\" data-align=\"left\"><code>collections.Counter<\/code> (\u5b57\u5178\u7684\u5b50\u7c7b)<\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\">\u53ea\u9700\u8981\u5b58\u50a8\u552f\u4e00\u503c\uff0c\u4e0d\u9700\u8981\u5173\u8054\u6570\u636e<\/td><td class=\"has-text-align-left\" data-align=\"left\"><code>set<\/code> (\u96c6\u5408)<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">\u5b57\u5178\u662f Python \u7684\u7075\u9b42\u6570\u636e\u7ed3\u6784\u3002\u638c\u63e1\u4e86 <code>.get()<\/code> \u9632\u9519\u3001<code>.items()<\/code> \u904d\u5386\u3001\u63a8\u5bfc\u5f0f\u4ee5\u53ca Python 3.9 \u7684 <code>|<\/code> \u5408\u5e76\u8fd0\u7b97\u7b26\uff0c\u4f60\u7684 Python \u4ee3\u7801\u5c31\u4f1a\u663e\u5f97\u975e\u5e38\u4e13\u4e1a\u548c\u73b0\u4ee3\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4f60\u76ee\u524d\u662f\u5426\u6709\u5904\u7406\u590d\u6742 JSON \u6570\u636e\u3001\u6216\u8005\u9700\u8981\u5d4c\u5957\u5b57\u5178\u7684\u5177\u4f53\u573a\u666f\uff1f\u6211\u53ef\u4ee5\u4e3a\u4f60\u6f14\u793a\u5982\u4f55\u4f18\u96c5\u5730\u89e3\u6790\u548c\u64cd\u4f5c\u5b83\u4eec\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5728 Python 3 \u4e2d\uff0c\u5b57\u5178\uff08Dictionar&#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-95","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\/95","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=95"}],"version-history":[{"count":1,"href":"https:\/\/www.52runoob.com\/index.php\/wp-json\/wp\/v2\/posts\/95\/revisions"}],"predecessor-version":[{"id":96,"href":"https:\/\/www.52runoob.com\/index.php\/wp-json\/wp\/v2\/posts\/95\/revisions\/96"}],"wp:attachment":[{"href":"https:\/\/www.52runoob.com\/index.php\/wp-json\/wp\/v2\/media?parent=95"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.52runoob.com\/index.php\/wp-json\/wp\/v2\/categories?post=95"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.52runoob.com\/index.php\/wp-json\/wp\/v2\/tags?post=95"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}