{"id":1138988,"date":"2025-01-08T22:05:45","date_gmt":"2025-01-08T14:05:45","guid":{"rendered":"https:\/\/docs.pingcode.com\/ask\/ask-ask\/1138988.html"},"modified":"2025-01-08T22:05:47","modified_gmt":"2025-01-08T14:05:47","slug":"python%e4%b8%ad%e5%a6%82%e4%bd%95%e5%8f%96%e6%96%87%e4%bb%b6%e4%b8%ad%e6%9f%90%e4%b8%80%e7%89%b9%e5%ae%9a%e7%9a%84%e8%a1%8c","status":"publish","type":"post","link":"https:\/\/docs.pingcode.com\/ask\/1138988.html","title":{"rendered":"python\u4e2d\u5982\u4f55\u53d6\u6587\u4ef6\u4e2d\u67d0\u4e00\u7279\u5b9a\u7684\u884c"},"content":{"rendered":"<p style=\"text-align:center;\" ><img decoding=\"async\" src=\"https:\/\/cdn-kb.worktile.com\/kb\/wp-content\/uploads\/2024\/04\/25102429\/430e174e-9ff8-4abf-a405-b7275b6c4585.webp\" alt=\"python\u4e2d\u5982\u4f55\u53d6\u6587\u4ef6\u4e2d\u67d0\u4e00\u7279\u5b9a\u7684\u884c\" \/><\/p>\n<p><p> <strong>\u5728Python\u4e2d\uff0c\u53d6\u6587\u4ef6\u4e2d\u7279\u5b9a\u7684\u884c\u53ef\u4ee5\u901a\u8fc7\u591a\u79cd\u65b9\u6cd5\u5b9e\u73b0\uff0c\u5305\u62ec\u9010\u884c\u8bfb\u53d6\u3001\u4f7f\u7528\u5217\u8868\u7d22\u5f15\u4ee5\u53ca\u5176\u4ed6\u9ad8\u6548\u7684\u65b9\u6cd5\u3002<\/strong> <\/p>\n<\/p>\n<p><p>\u4e00\u79cd\u5e38\u7528\u4e14\u7b80\u5355\u7684\u65b9\u6cd5\u662f\u5c06\u6587\u4ef6\u9010\u884c\u8bfb\u53d6\u5230\u4e00\u4e2a\u5217\u8868\uff0c\u7136\u540e\u901a\u8fc7\u7d22\u5f15\u8bbf\u95ee\u7279\u5b9a\u7684\u884c\u3002\u8fd9\u79cd\u65b9\u6cd5\u9002\u5408\u5c0f\u6587\u4ef6\uff0c\u5bf9\u4e8e\u5927\u6587\u4ef6\u5219\u53ef\u80fd\u9700\u8981\u66f4\u9ad8\u6548\u7684\u65b9\u6cd5\uff0c\u5982\u4f7f\u7528\u751f\u6210\u5668\u6216\u5185\u5b58\u6620\u5c04\u6587\u4ef6\uff08memory-mapped files\uff09\u3002\u63a5\u4e0b\u6765\uff0c\u6211\u4eec\u5c06\u8be6\u7ec6\u63a2\u8ba8\u51e0\u79cd\u4e0d\u540c\u7684\u65b9\u6cd5\uff0c\u5e76\u7ed9\u51fa\u4ee3\u7801\u793a\u4f8b\u3002<\/p>\n<\/p>\n<p><h3>\u4e00\u3001\u9010\u884c\u8bfb\u53d6\u6587\u4ef6\u5e76\u5b58\u50a8\u5728\u5217\u8868\u4e2d<\/h3>\n<\/p>\n<p><p>\u8fd9\u662f\u6700\u76f4\u63a5\u7684\u65b9\u6cd5\uff0c\u9002\u5408\u5c0f\u6587\u4ef6\u3002\u6211\u4eec\u5c06\u6587\u4ef6\u7684\u6bcf\u4e00\u884c\u8bfb\u53d6\u5e76\u5b58\u50a8\u5728\u4e00\u4e2a\u5217\u8868\u4e2d\uff0c\u7136\u540e\u901a\u8fc7\u7d22\u5f15\u8bbf\u95ee\u9700\u8981\u7684\u884c\u3002<\/p>\n<\/p>\n<p><pre><code class=\"language-python\">def read_specific_line(file_path, line_number):<\/p>\n<p>    with open(file_path, &#39;r&#39;) as file:<\/p>\n<p>        lines = file.readlines()<\/p>\n<p>    return lines[line_number - 1]<\/p>\n<p>file_path = &#39;example.txt&#39;<\/p>\n<p>line_number = 3<\/p>\n<p>print(read_specific_line(file_path, line_number))<\/p>\n<p><\/code><\/pre>\n<\/p>\n<p><p>\u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0c<code>readlines()<\/code> \u65b9\u6cd5\u5c06\u6574\u4e2a\u6587\u4ef6\u8bfb\u53d6\u5230\u4e00\u4e2a\u5217\u8868\u4e2d\uff0c\u6bcf\u4e2a\u5143\u7d20\u5bf9\u5e94\u6587\u4ef6\u4e2d\u7684\u4e00\u884c\u3002<strong>\u901a\u8fc7\u7d22\u5f15\u8bbf\u95ee\u7279\u5b9a\u884c\u975e\u5e38\u65b9\u4fbf\uff0c\u4f46\u8fd9\u79cd\u65b9\u6cd5\u4f1a\u5c06\u6574\u4e2a\u6587\u4ef6\u52a0\u8f7d\u5230\u5185\u5b58\u4e2d\uff0c\u9002\u5408\u5904\u7406\u5c0f\u6587\u4ef6\u3002<\/strong><\/p>\n<\/p>\n<p><h3>\u4e8c\u3001\u4f7f\u7528\u751f\u6210\u5668\u9010\u884c\u8bfb\u53d6\u6587\u4ef6<\/h3>\n<\/p>\n<p><p>\u5bf9\u4e8e\u5927\u6587\u4ef6\uff0c\u9010\u884c\u8bfb\u53d6\u800c\u4e0d\u5c06\u6574\u4e2a\u6587\u4ef6\u52a0\u8f7d\u5230\u5185\u5b58\u4e2d\u662f\u66f4\u597d\u7684\u9009\u62e9\u3002\u751f\u6210\u5668\u662f\u5904\u7406\u8fd9\u79cd\u60c5\u51b5\u7684\u7406\u60f3\u5de5\u5177\u3002<\/p>\n<\/p>\n<p><pre><code class=\"language-python\">def read_specific_line(file_path, line_number):<\/p>\n<p>    with open(file_path, &#39;r&#39;) as file:<\/p>\n<p>        for current_line_number, line in enumerate(file, start=1):<\/p>\n<p>            if current_line_number == line_number:<\/p>\n<p>                return line<\/p>\n<p>file_path = &#39;example.txt&#39;<\/p>\n<p>line_number = 3<\/p>\n<p>print(read_specific_line(file_path, line_number))<\/p>\n<p><\/code><\/pre>\n<\/p>\n<p><p>\u4f7f\u7528\u751f\u6210\u5668\uff0c\u6211\u4eec\u53ef\u4ee5\u9010\u884c\u8bfb\u53d6\u6587\u4ef6\uff0c\u76f4\u5230\u627e\u5230\u6211\u4eec\u9700\u8981\u7684\u884c\u3002\u8fd9\u79cd\u65b9\u6cd5\u53ea\u5728\u5185\u5b58\u4e2d\u5b58\u50a8\u5f53\u524d\u884c\uff0c\u56e0\u6b64\u9002\u5408\u5904\u7406\u5927\u6587\u4ef6\u3002<\/p>\n<\/p>\n<p><h3>\u4e09\u3001\u5185\u5b58\u6620\u5c04\u6587\u4ef6\uff08memory-mapped files\uff09<\/h3>\n<\/p>\n<p><p>\u5bf9\u4e8e\u975e\u5e38\u5927\u7684\u6587\u4ef6\uff0c\u5185\u5b58\u6620\u5c04\u6587\u4ef6\u63d0\u4f9b\u4e86\u4e00\u79cd\u9ad8\u6548\u7684\u8bfb\u53d6\u65b9\u5f0f\u3002Python \u7684 <code>mmap<\/code> \u6a21\u5757\u5141\u8bb8\u6211\u4eec\u5c06\u6587\u4ef6\u7684\u4e00\u90e8\u5206\u6620\u5c04\u5230\u5185\u5b58\u4e2d\uff0c\u4ece\u800c\u5b9e\u73b0\u9ad8\u6548\u7684\u6587\u4ef6\u64cd\u4f5c\u3002<\/p>\n<\/p>\n<p><pre><code class=\"language-python\">import mmap<\/p>\n<p>def read_specific_line(file_path, line_number):<\/p>\n<p>    with open(file_path, &#39;r&#39;) as file:<\/p>\n<p>        mmapped_file = mmap.mmap(file.fileno(), 0, access=mmap.ACCESS_READ)<\/p>\n<p>        current_line_number = 0<\/p>\n<p>        for line in iter(mmapped_file.readline, b&quot;&quot;):<\/p>\n<p>            current_line_number += 1<\/p>\n<p>            if current_line_number == line_number:<\/p>\n<p>                return line.decode(&#39;utf-8&#39;)<\/p>\n<p>file_path = &#39;example.txt&#39;<\/p>\n<p>line_number = 3<\/p>\n<p>print(read_specific_line(file_path, line_number))<\/p>\n<p><\/code><\/pre>\n<\/p>\n<p><p>\u4f7f\u7528 <code>mmap<\/code> \u6a21\u5757\uff0c\u6211\u4eec\u53ef\u4ee5\u5c06\u6587\u4ef6\u7684\u4e00\u90e8\u5206\u6620\u5c04\u5230\u5185\u5b58\u4e2d\uff0c\u4ece\u800c\u5b9e\u73b0\u66f4\u9ad8\u6548\u7684\u6587\u4ef6\u64cd\u4f5c\u3002\u8fd9\u79cd\u65b9\u6cd5\u9002\u5408\u5904\u7406\u975e\u5e38\u5927\u7684\u6587\u4ef6\uff0c\u56e0\u4e3a\u5b83\u4e0d\u4f1a\u5c06\u6574\u4e2a\u6587\u4ef6\u52a0\u8f7d\u5230\u5185\u5b58\u4e2d\u3002<\/p>\n<\/p>\n<p><h3>\u56db\u3001\u4f7f\u7528 pandas \u8bfb\u53d6\u7279\u5b9a\u884c<\/h3>\n<\/p>\n<p><p>\u5982\u679c\u6587\u4ef6\u662f\u7ed3\u6784\u5316\u7684\uff08\u4f8b\u5982CSV\u6587\u4ef6\uff09\uff0c\u53ef\u4ee5\u4f7f\u7528 <code>pandas<\/code> \u5e93\u8bfb\u53d6\u7279\u5b9a\u884c\u3002<\/p>\n<\/p>\n<p><pre><code class=\"language-python\">import pandas as pd<\/p>\n<p>def read_specific_line(file_path, line_number):<\/p>\n<p>    df = pd.read_csv(file_path, header=None, skiprows=line_number-1, nrows=1)<\/p>\n<p>    return df.iloc[0]<\/p>\n<p>file_path = &#39;example.csv&#39;<\/p>\n<p>line_number = 3<\/p>\n<p>print(read_specific_line(file_path, line_number))<\/p>\n<p><\/code><\/pre>\n<\/p>\n<p><p><strong><code>pandas<\/code> \u5e93\u63d0\u4f9b\u4e86\u975e\u5e38\u5f3a\u5927\u7684\u6570\u636e\u5904\u7406\u529f\u80fd\uff0c\u9002\u5408\u5904\u7406\u7ed3\u6784\u5316\u6570\u636e\u6587\u4ef6\u3002<\/strong> \u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0c\u6211\u4eec\u4f7f\u7528 <code>read_csv<\/code> \u51fd\u6570\u8bfb\u53d6\u7279\u5b9a\u884c\uff0c\u5e76\u4f7f\u7528 <code>iloc<\/code> \u65b9\u6cd5\u8bbf\u95ee\u8be5\u884c\u3002<\/p>\n<\/p>\n<p><h3>\u4e94\u3001\u603b\u7ed3<\/h3>\n<\/p>\n<p><p>\u5728Python\u4e2d\u8bfb\u53d6\u6587\u4ef6\u4e2d\u7279\u5b9a\u884c\u7684\u65b9\u6cd5\u6709\u5f88\u591a\uff0c\u9009\u62e9\u5408\u9002\u7684\u65b9\u6cd5\u53d6\u51b3\u4e8e\u5177\u4f53\u7684\u9700\u6c42\u548c\u6587\u4ef6\u5927\u5c0f\u3002<strong>\u5bf9\u4e8e\u5c0f\u6587\u4ef6\uff0c\u53ef\u4ee5\u5c06\u6587\u4ef6\u8bfb\u53d6\u5230\u5217\u8868\u4e2d\uff0c\u901a\u8fc7\u7d22\u5f15\u8bbf\u95ee\u7279\u5b9a\u884c\u3002\u5bf9\u4e8e\u5927\u6587\u4ef6\uff0c\u751f\u6210\u5668\u548c\u5185\u5b58\u6620\u5c04\u6587\u4ef6\u662f\u66f4\u9ad8\u6548\u7684\u9009\u62e9\u3002<\/strong> \u5982\u679c\u5904\u7406\u7684\u662f\u7ed3\u6784\u5316\u6570\u636e\u6587\u4ef6\uff0c<code>pandas<\/code> \u5e93\u63d0\u4f9b\u4e86\u975e\u5e38\u65b9\u4fbf\u7684\u64cd\u4f5c\u65b9\u6cd5\u3002<\/p>\n<\/p>\n<p><p>\u65e0\u8bba\u9009\u62e9\u54ea\u79cd\u65b9\u6cd5\uff0c\u90fd\u9700\u8981\u6ce8\u610f\u6587\u4ef6\u7684\u7f16\u7801\u548c\u6362\u884c\u7b26\u5904\u7406\uff0c\u4ee5\u786e\u4fdd\u8bfb\u53d6\u7684\u5185\u5bb9\u51c6\u786e\u65e0\u8bef\u3002\u638c\u63e1\u8fd9\u4e9b\u65b9\u6cd5\uff0c\u80fd\u591f\u5e2e\u52a9\u6211\u4eec\u5728\u5b9e\u9645\u9879\u76ee\u4e2d\u66f4\u9ad8\u6548\u5730\u5904\u7406\u6587\u4ef6\u64cd\u4f5c\u3002<\/p>\n<\/p>\n<h2><strong>\u76f8\u5173\u95ee\u7b54FAQs\uff1a<\/strong><\/h2>\n<p> <strong>\u5982\u4f55\u5728Python\u4e2d\u8bfb\u53d6\u7279\u5b9a\u884c\u7684\u6587\u4ef6\u5185\u5bb9\uff1f<\/strong><br \/>\u5728Python\u4e2d\uff0c\u53ef\u4ee5\u4f7f\u7528\u591a\u79cd\u65b9\u6cd5\u6765\u8bfb\u53d6\u6587\u4ef6\u4e2d\u7279\u5b9a\u7684\u884c\u3002\u6700\u5e38\u89c1\u7684\u65b9\u6cd5\u662f\u4f7f\u7528<code>readlines()<\/code>\u51fd\u6570\uff0c\u8be5\u51fd\u6570\u5c06\u6587\u4ef6\u7684\u6240\u6709\u884c\u8bfb\u5165\u4e00\u4e2a\u5217\u8868\u4e2d\uff0c\u4e4b\u540e\u53ef\u4ee5\u901a\u8fc7\u7d22\u5f15\u8bbf\u95ee\u7279\u5b9a\u7684\u884c\u3002\u4f8b\u5982\uff0c<code>lines = open(&#39;filename.txt&#39;).readlines()<\/code>\u53ef\u4ee5\u8bfb\u53d6\u6587\u4ef6\uff0c<code>specific_line = lines[line_number]<\/code>\u53ef\u4ee5\u83b7\u53d6\u7279\u5b9a\u884c\u3002<\/p>\n<p><strong>\u4f7f\u7528Python\u8bfb\u53d6\u6587\u4ef6\u65f6\uff0c\u6709\u6ca1\u6709\u5176\u4ed6\u9ad8\u6548\u7684\u65b9\u6cd5\uff1f<\/strong><br \/>\u9664\u4e86<code>readlines()<\/code>\uff0c\u53ef\u4ee5\u4f7f\u7528<code>enumerate()<\/code>\u7ed3\u5408\u6587\u4ef6\u5bf9\u8c61\u8fdb\u884c\u9010\u884c\u8bfb\u53d6\uff0c\u4ece\u800c\u5728\u5185\u5b58\u4f7f\u7528\u4e0a\u66f4\u4e3a\u9ad8\u6548\u3002\u901a\u8fc7\u8fd9\u79cd\u65b9\u5f0f\uff0c\u4f60\u53ef\u4ee5\u5728\u8bfb\u53d6\u6bcf\u4e00\u884c\u65f6\u68c0\u67e5\u884c\u53f7\uff0c\u627e\u5230\u6240\u9700\u7684\u7279\u5b9a\u884c\u3002\u4f8b\u5982\uff1a  <\/p>\n<pre><code class=\"language-python\">with open(&#39;filename.txt&#39;) as file:\n    for index, line in enumerate(file):\n        if index == target_line_number:\n            print(line)\n<\/code><\/pre>\n<p>\u8fd9\u79cd\u65b9\u6cd5\u907f\u514d\u4e86\u4e00\u6b21\u6027\u5c06\u6574\u4e2a\u6587\u4ef6\u5185\u5bb9\u52a0\u8f7d\u5230\u5185\u5b58\u4e2d\u3002<\/p>\n<p><strong>\u5728Python\u4e2d\uff0c\u5982\u4f55\u5904\u7406\u8bfb\u53d6\u7279\u5b9a\u884c\u65f6\u7684\u5f02\u5e38\u60c5\u51b5\uff1f<\/strong><br \/>\u5f53\u8bfb\u53d6\u6587\u4ef6\u7684\u7279\u5b9a\u884c\u65f6\uff0c\u53ef\u80fd\u4f1a\u9047\u5230\u4e00\u4e9b\u5f02\u5e38\u60c5\u51b5\uff0c\u4f8b\u5982\u6587\u4ef6\u4e0d\u5b58\u5728\u6216\u884c\u53f7\u8d85\u51fa\u8303\u56f4\u3002\u53ef\u4ee5\u901a\u8fc7\u5f02\u5e38\u5904\u7406\u673a\u5236\u6765\u6355\u6349\u8fd9\u4e9b\u9519\u8bef\u3002\u4f7f\u7528<code>try...except<\/code>\u5757\u6765\u786e\u4fdd\u7a0b\u5e8f\u5728\u9047\u5230\u95ee\u9898\u65f6\u4e0d\u4f1a\u5d29\u6e83\uff0c\u793a\u4f8b\u4ee3\u7801\u5982\u4e0b\uff1a  <\/p>\n<pre><code class=\"language-python\">try:\n    with open(&#39;filename.txt&#39;) as file:\n        lines = file.readlines()\n        print(lines[line_number])  # \u6839\u636e\u9700\u8981\u7684\u884c\u53f7\u8bfb\u53d6\nexcept FileNotFoundError:\n    print(&quot;\u6587\u4ef6\u672a\u627e\u5230\uff0c\u8bf7\u68c0\u67e5\u6587\u4ef6\u540d\u548c\u8def\u5f84\u3002&quot;)\nexcept IndexError:\n    print(&quot;\u884c\u53f7\u8d85\u51fa\u8303\u56f4\uff0c\u8bf7\u63d0\u4f9b\u6709\u6548\u7684\u884c\u53f7\u3002&quot;)\n<\/code><\/pre>\n<p>\u8fd9\u79cd\u65b9\u5f0f\u53ef\u4ee5\u63d0\u9ad8\u4ee3\u7801\u7684\u5065\u58ee\u6027\u548c\u53ef\u8bfb\u6027\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"\u5728Python\u4e2d\uff0c\u53d6\u6587\u4ef6\u4e2d\u7279\u5b9a\u7684\u884c\u53ef\u4ee5\u901a\u8fc7\u591a\u79cd\u65b9\u6cd5\u5b9e\u73b0\uff0c\u5305\u62ec\u9010\u884c\u8bfb\u53d6\u3001\u4f7f\u7528\u5217\u8868\u7d22\u5f15\u4ee5\u53ca\u5176\u4ed6\u9ad8\u6548\u7684\u65b9\u6cd5\u3002 \u4e00\u79cd\u5e38 [&hellip;]","protected":false},"author":3,"featured_media":1138995,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[37],"tags":[],"acf":[],"_links":{"self":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/1138988"}],"collection":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/comments?post=1138988"}],"version-history":[{"count":"1","href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/1138988\/revisions"}],"predecessor-version":[{"id":1138999,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/1138988\/revisions\/1138999"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/media\/1138995"}],"wp:attachment":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/media?parent=1138988"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/categories?post=1138988"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/tags?post=1138988"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}