{"id":1063828,"date":"2024-12-31T16:03:50","date_gmt":"2024-12-31T08:03:50","guid":{"rendered":"https:\/\/docs.pingcode.com\/ask\/ask-ask\/1063828.html"},"modified":"2024-12-31T16:03:52","modified_gmt":"2024-12-31T08:03:52","slug":"python%e5%a6%82%e4%bd%95%e6%89%be%e5%88%b0%e6%96%87%e4%bb%b6%e6%9c%80%e5%90%8e%e4%b8%80%e8%a1%8c","status":"publish","type":"post","link":"https:\/\/docs.pingcode.com\/ask\/1063828.html","title":{"rendered":"python\u5982\u4f55\u627e\u5230\u6587\u4ef6\u6700\u540e\u4e00\u884c"},"content":{"rendered":"<p style=\"text-align:center;\" ><img decoding=\"async\" src=\"https:\/\/cdn-docs.pingcode.com\/wp-content\/uploads\/2024\/12\/b6a9e569-c447-4893-9f73-e0895f5f7c43.webp?x-oss-process=image\/auto-orient,1\/format,webp\" alt=\"python\u5982\u4f55\u627e\u5230\u6587\u4ef6\u6700\u540e\u4e00\u884c\" \/><\/p>\n<p><p> <strong>\u8981\u627e\u5230\u6587\u4ef6\u7684\u6700\u540e\u4e00\u884c\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u65b9\u6cd5\uff1a\u4f7f\u7528readlines()\u65b9\u6cd5\u8bfb\u53d6\u6240\u6709\u884c\u3001\u4f7f\u7528seek()\u548ctell()\u65b9\u6cd5\u4ece\u6587\u4ef6\u672b\u5c3e\u5411\u524d\u8bfb\u53d6\u3001\u4f7f\u7528\u5185\u7f6e\u6a21\u5757linecache\u8bfb\u53d6\u7279\u5b9a\u884c\u3002\u6700\u5e38\u7528\u7684\u65b9\u6cd5\u662f\u4f7f\u7528readlines()\u65b9\u6cd5\u8bfb\u53d6\u6240\u6709\u884c\uff0c\u7136\u540e\u83b7\u53d6\u6700\u540e\u4e00\u884c\u3002<\/strong><\/p>\n<\/p>\n<p><p>Python \u63d0\u4f9b\u4e86\u591a\u79cd\u65b9\u6cd5\u6765\u8bfb\u53d6\u6587\u4ef6\u7684\u6700\u540e\u4e00\u884c\u3002\u4e0b\u9762\u6211\u5c06\u8be6\u7ec6\u4ecb\u7ecd\u8fd9\u4e9b\u65b9\u6cd5\uff0c\u5e76\u89e3\u91ca\u6bcf\u79cd\u65b9\u6cd5\u7684\u4f18\u7f3a\u70b9\u3002<\/p>\n<\/p>\n<p><h3>\u4e00\u3001\u4f7f\u7528readlines()\u65b9\u6cd5\u8bfb\u53d6\u6240\u6709\u884c<\/h3>\n<\/p>\n<p><p>\u4f7f\u7528readlines()\u65b9\u6cd5\u662f\u6700\u7b80\u5355\u76f4\u63a5\u7684\u65b9\u6cd5\u4e4b\u4e00\u3002\u8fd9\u79cd\u65b9\u6cd5\u9002\u7528\u4e8e\u5c0f\u6587\u4ef6\uff0c\u56e0\u4e3a\u5b83\u4f1a\u5c06\u6587\u4ef6\u7684\u6240\u6709\u884c\u8bfb\u53d6\u5230\u5185\u5b58\u4e2d\u3002<\/p>\n<\/p>\n<p><pre><code class=\"language-python\">with open(&#39;example.txt&#39;, &#39;r&#39;) as file:<\/p>\n<p>    lines = file.readlines()<\/p>\n<p>    last_line = lines[-1]<\/p>\n<p>    print(last_line)<\/p>\n<p><\/code><\/pre>\n<\/p>\n<p><p><strong>\u4f18\u70b9\uff1a<\/strong><\/p>\n<\/p>\n<ul>\n<li>\u7b80\u5355\u6613\u7528\uff0c\u4ee3\u7801\u6613\u4e8e\u7406\u89e3\u3002<\/li>\n<li>\u9002\u7528\u4e8e\u5c0f\u6587\u4ef6\u3002<\/li>\n<\/ul>\n<p><p><strong>\u7f3a\u70b9\uff1a<\/strong><\/p>\n<\/p>\n<ul>\n<li>\u5bf9\u4e8e\u5927\u6587\u4ef6\uff0c\u5185\u5b58\u5360\u7528\u8f83\u9ad8\uff0c\u56e0\u4e3a\u9700\u8981\u5c06\u6574\u4e2a\u6587\u4ef6\u8bfb\u53d6\u5230\u5185\u5b58\u4e2d\u3002<\/li>\n<\/ul>\n<p><h3>\u4e8c\u3001\u4f7f\u7528seek()\u548ctell()\u65b9\u6cd5\u4ece\u6587\u4ef6\u672b\u5c3e\u5411\u524d\u8bfb\u53d6<\/h3>\n<\/p>\n<p><p>\u8fd9\u79cd\u65b9\u6cd5\u9002\u7528\u4e8e\u5927\u6587\u4ef6\uff0c\u56e0\u4e3a\u5b83\u4e0d\u9700\u8981\u5c06\u6574\u4e2a\u6587\u4ef6\u8bfb\u53d6\u5230\u5185\u5b58\u4e2d\u3002\u5b83\u901a\u8fc7\u9010\u5b57\u8282\u5730\u4ece\u6587\u4ef6\u672b\u5c3e\u5411\u524d\u8bfb\u53d6\uff0c\u76f4\u5230\u627e\u5230\u6362\u884c\u7b26\u3002<\/p>\n<\/p>\n<p><pre><code class=\"language-python\">with open(&#39;example.txt&#39;, &#39;rb&#39;) as file:<\/p>\n<p>    file.seek(-2, 2)  # \u4ece\u6587\u4ef6\u672b\u5c3e\u5411\u524d\u79fb\u52a8\u4e24\u4e2a\u5b57\u8282<\/p>\n<p>    while file.read(1) != b&#39;\\n&#39;:  # \u8bfb\u53d6\u4e00\u4e2a\u5b57\u8282\uff0c\u68c0\u67e5\u662f\u5426\u4e3a\u6362\u884c\u7b26<\/p>\n<p>        file.seek(-2, 1)  # \u5411\u540e\u79fb\u52a8\u4e24\u4e2a\u5b57\u8282<\/p>\n<p>    last_line = file.readline().decode()  # \u8bfb\u53d6\u6700\u540e\u4e00\u884c\u5e76\u89e3\u7801<\/p>\n<p>    print(last_line)<\/p>\n<p><\/code><\/pre>\n<\/p>\n<p><p><strong>\u4f18\u70b9\uff1a<\/strong><\/p>\n<\/p>\n<ul>\n<li>\u9002\u7528\u4e8e\u5927\u6587\u4ef6\uff0c\u56e0\u4e3a\u4e0d\u4f1a\u5c06\u6574\u4e2a\u6587\u4ef6\u8bfb\u53d6\u5230\u5185\u5b58\u4e2d\u3002<\/li>\n<li>\u66f4\u9ad8\u6548\uff0c\u5c24\u5176\u662f\u5bf9\u4e8e\u975e\u5e38\u5927\u7684\u6587\u4ef6\u3002<\/li>\n<\/ul>\n<p><p><strong>\u7f3a\u70b9\uff1a<\/strong><\/p>\n<\/p>\n<ul>\n<li>\u4ee3\u7801\u590d\u6742\u5ea6\u8f83\u9ad8\uff0c\u96be\u4ee5\u7406\u89e3\u548c\u7ef4\u62a4\u3002<\/li>\n<li>\u9700\u8981\u5904\u7406\u5b57\u8282\u64cd\u4f5c\u548c\u89e3\u7801\u3002<\/li>\n<\/ul>\n<p><h3>\u4e09\u3001\u4f7f\u7528\u5185\u7f6e\u6a21\u5757linecache\u8bfb\u53d6\u7279\u5b9a\u884c<\/h3>\n<\/p>\n<p><p>linecache\u6a21\u5757\u5141\u8bb8\u6211\u4eec\u8bfb\u53d6\u6587\u4ef6\u4e2d\u7684\u7279\u5b9a\u884c\uff0c\u8fd9\u5bf9\u4e8e\u8c03\u8bd5\u548c\u65e5\u5fd7\u6587\u4ef6\u975e\u5e38\u6709\u7528\u3002<\/p>\n<\/p>\n<p><pre><code class=\"language-python\">import linecache<\/p>\n<p>def get_last_line(filename):<\/p>\n<p>    lines = linecache.getlines(filename)<\/p>\n<p>    return lines[-1]<\/p>\n<p>last_line = get_last_line(&#39;example.txt&#39;)<\/p>\n<p>print(last_line)<\/p>\n<p><\/code><\/pre>\n<\/p>\n<p><p><strong>\u4f18\u70b9\uff1a<\/strong><\/p>\n<\/p>\n<ul>\n<li>\u4ee3\u7801\u7b80\u5355\uff0c\u6613\u4e8e\u7406\u89e3\u3002<\/li>\n<li>\u9002\u7528\u4e8e\u5c0f\u6587\u4ef6\u548c\u4e2d\u7b49\u5927\u5c0f\u7684\u6587\u4ef6\u3002<\/li>\n<\/ul>\n<p><p><strong>\u7f3a\u70b9\uff1a<\/strong><\/p>\n<\/p>\n<ul>\n<li>\u5bf9\u4e8e\u975e\u5e38\u5927\u7684\u6587\u4ef6\uff0c\u6027\u80fd\u8f83\u4f4e\uff0c\u56e0\u4e3alinecache\u4f1a\u7f13\u5b58\u6574\u4e2a\u6587\u4ef6\u3002<\/li>\n<\/ul>\n<p><h3>\u56db\u3001\u4f7f\u7528deque\u8bfb\u53d6\u6587\u4ef6\u7684\u6700\u540en\u884c<\/h3>\n<\/p>\n<p><p>collections\u6a21\u5757\u4e2d\u7684deque\uff08\u53cc\u7aef\u961f\u5217\uff09\u53ef\u4ee5\u9ad8\u6548\u5730\u8bfb\u53d6\u6587\u4ef6\u7684\u6700\u540en\u884c\u3002\u8fd9\u4e2a\u65b9\u6cd5\u9002\u7528\u4e8e\u9700\u8981\u8bfb\u53d6\u6587\u4ef6\u6700\u540e\u51e0\u884c\u7684\u60c5\u51b5\u3002<\/p>\n<\/p>\n<p><pre><code class=\"language-python\">from collections import deque<\/p>\n<p>def t<a href=\"https:\/\/docs.pingcode.com\/blog\/59162.html\" target=\"_blank\">AI<\/a>l(filename, n=1):<\/p>\n<p>    with open(filename, &#39;r&#39;) as file:<\/p>\n<p>        return deque(file, n)<\/p>\n<p>last_line = tail(&#39;example.txt&#39;, 1).pop()<\/p>\n<p>print(last_line)<\/p>\n<p><\/code><\/pre>\n<\/p>\n<p><p><strong>\u4f18\u70b9\uff1a<\/strong><\/p>\n<\/p>\n<ul>\n<li>\u9ad8\u6548\uff0c\u9002\u7528\u4e8e\u5927\u6587\u4ef6\u3002<\/li>\n<li>\u7b80\u5355\u6613\u7528\uff0c\u4ee3\u7801\u6613\u4e8e\u7406\u89e3\u3002<\/li>\n<\/ul>\n<p><p><strong>\u7f3a\u70b9\uff1a<\/strong><\/p>\n<\/p>\n<ul>\n<li>\u9700\u8981\u5bfc\u5165collections\u6a21\u5757\u3002<\/li>\n<\/ul>\n<p><h3>\u4e94\u3001\u4f7f\u7528mmap\u6a21\u5757\u8fdb\u884c\u5185\u5b58\u6620\u5c04<\/h3>\n<\/p>\n<p><p>mmap\u6a21\u5757\u5141\u8bb8\u5c06\u6587\u4ef6\u6620\u5c04\u5230\u5185\u5b58\u4e2d\uff0c\u53ef\u4ee5\u9ad8\u6548\u5730\u8bfb\u53d6\u6587\u4ef6\u7684\u7279\u5b9a\u90e8\u5206\u3002<\/p>\n<\/p>\n<p><pre><code class=\"language-python\">import mmap<\/p>\n<p>def get_last_line(filename):<\/p>\n<p>    with open(filename, &#39;r&#39;) as file:<\/p>\n<p>        with mmap.mmap(file.fileno(), 0, access=mmap.ACCESS_READ) as mm:<\/p>\n<p>            lines = mm.rsplit(b&#39;\\n&#39;, 1)<\/p>\n<p>            return lines[-1].decode()<\/p>\n<p>last_line = get_last_line(&#39;example.txt&#39;)<\/p>\n<p>print(last_line)<\/p>\n<p><\/code><\/pre>\n<\/p>\n<p><p><strong>\u4f18\u70b9\uff1a<\/strong><\/p>\n<\/p>\n<ul>\n<li>\u9ad8\u6548\uff0c\u9002\u7528\u4e8e\u5927\u6587\u4ef6\u3002<\/li>\n<li>\u4ee3\u7801\u7b80\u6d01\uff0c\u6613\u4e8e\u7406\u89e3\u3002<\/li>\n<\/ul>\n<p><p><strong>\u7f3a\u70b9\uff1a<\/strong><\/p>\n<\/p>\n<ul>\n<li>\u9700\u8981\u5bfc\u5165mmap\u6a21\u5757\u3002<\/li>\n<li>\u9002\u7528\u4e8eUnix\u7cfb\u7edf\uff0c\u5728Windows\u7cfb\u7edf\u4e0a\u53ef\u80fd\u9700\u8981\u8c03\u6574\u3002<\/li>\n<\/ul>\n<p><h3>\u516d\u3001\u603b\u7ed3<\/h3>\n<\/p>\n<p><p>\u5728\u9009\u62e9\u65b9\u6cd5\u65f6\uff0c\u53ef\u4ee5\u6839\u636e\u6587\u4ef6\u7684\u5927\u5c0f\u548c\u4ee3\u7801\u7684\u590d\u6742\u5ea6\u8fdb\u884c\u6743\u8861\uff1a<\/p>\n<\/p>\n<ul>\n<li><strong>\u5bf9\u4e8e\u5c0f\u6587\u4ef6<\/strong>\uff0c\u53ef\u4ee5\u4f7f\u7528readlines()\u65b9\u6cd5\u6216linecache\u6a21\u5757\uff0c\u56e0\u4e3a\u5b83\u4eec\u7b80\u5355\u6613\u7528\u3002<\/li>\n<li><strong>\u5bf9\u4e8e\u5927\u6587\u4ef6<\/strong>\uff0c\u5efa\u8bae\u4f7f\u7528seek()\u548ctell()\u65b9\u6cd5\u3001deque\u65b9\u6cd5\u6216mmap\u6a21\u5757\uff0c\u56e0\u4e3a\u5b83\u4eec\u66f4\u9ad8\u6548\uff0c\u4e0d\u4f1a\u5360\u7528\u8fc7\u591a\u5185\u5b58\u3002<\/li>\n<\/ul>\n<p><p>\u6bcf\u79cd\u65b9\u6cd5\u90fd\u6709\u5176\u4f18\u7f3a\u70b9\uff0c\u6839\u636e\u5177\u4f53\u60c5\u51b5\u9009\u62e9\u6700\u5408\u9002\u7684\u65b9\u6cd5\uff0c\u4ee5\u786e\u4fdd\u4ee3\u7801\u7684\u9ad8\u6548\u6027\u548c\u53ef\u7ef4\u62a4\u6027\u3002<\/p>\n<\/p>\n<h2><strong>\u76f8\u5173\u95ee\u7b54FAQs\uff1a<\/strong><\/h2>\n<p> <strong>\u5982\u4f55\u4f7f\u7528Python\u8bfb\u53d6\u6587\u4ef6\u7684\u6700\u540e\u4e00\u884c\uff1f<\/strong><br \/>\u53ef\u4ee5\u4f7f\u7528\u591a\u79cd\u65b9\u6cd5\u6765\u8bfb\u53d6\u6587\u4ef6\u7684\u6700\u540e\u4e00\u884c\u3002\u4e00\u79cd\u5e38\u89c1\u7684\u65b9\u5f0f\u662f\u6253\u5f00\u6587\u4ef6\u5e76\u4f7f\u7528<code>readlines()<\/code>\u65b9\u6cd5\u5c06\u6240\u6709\u884c\u8bfb\u5165\u4e00\u4e2a\u5217\u8868\uff0c\u7136\u540e\u83b7\u53d6\u6700\u540e\u4e00\u4e2a\u5143\u7d20\u3002\u4f8b\u5982\uff0c\u4f7f\u7528<code>with open(&#39;filename.txt&#39;) as f:<\/code>\u8bed\u53e5\u53ef\u4ee5\u786e\u4fdd\u5728\u8bfb\u53d6\u540e\u81ea\u52a8\u5173\u95ed\u6587\u4ef6\u3002\u8fd8\u6709\u4e00\u79cd\u66f4\u9ad8\u6548\u7684\u65b9\u6cd5\u662f\u4f7f\u7528<code>seek()<\/code>\u548c<code>readline()<\/code>\u65b9\u6cd5\uff0c\u76f4\u63a5\u4ece\u6587\u4ef6\u672b\u5c3e\u5f00\u59cb\u8bfb\u53d6\uff0c\u8fd9\u6837\u53ef\u4ee5\u907f\u514d\u5c06\u6574\u4e2a\u6587\u4ef6\u52a0\u8f7d\u5230\u5185\u5b58\u4e2d\u3002<\/p>\n<p><strong>\u5728\u5904\u7406\u5927\u578b\u6587\u4ef6\u65f6\uff0c\u5982\u4f55\u6709\u6548\u83b7\u53d6\u6700\u540e\u4e00\u884c\uff1f<\/strong><br \/>\u5bf9\u4e8e\u975e\u5e38\u5927\u7684\u6587\u4ef6\uff0c\u4f7f\u7528\u5185\u5b58\u6548\u7387\u9ad8\u7684\u65b9\u6cd5\u5c24\u4e3a\u91cd\u8981\u3002\u53ef\u4ee5\u901a\u8fc7\u4ece\u6587\u4ef6\u672b\u5c3e\u5411\u524d\u67e5\u627e\u7684\u65b9\u5f0f\u5b9e\u73b0\u3002\u6253\u5f00\u6587\u4ef6\u540e\uff0c\u53ef\u4ee5\u4f7f\u7528<code>f.seek(0, 2)<\/code>\u5c06\u6587\u4ef6\u6307\u9488\u79fb\u52a8\u5230\u6587\u4ef6\u672b\u5c3e\uff0c\u7136\u540e\u5411\u524d\u8bfb\u53d6\u5b57\u7b26\uff0c\u76f4\u5230\u627e\u5230\u6362\u884c\u7b26\uff0c\u8fd9\u6837\u53ef\u4ee5\u907f\u514d\u8bfb\u53d6\u6574\u4e2a\u6587\u4ef6\uff0c\u8282\u7701\u5185\u5b58\u3002<\/p>\n<p><strong>\u4f7f\u7528Python\u83b7\u53d6\u6700\u540e\u4e00\u884c\u65f6\uff0c\u5982\u4f55\u5904\u7406\u6587\u4ef6\u7f16\u7801\u95ee\u9898\uff1f<\/strong><br \/>\u5728\u8bfb\u53d6\u6587\u4ef6\u65f6\uff0c\u7f16\u7801\u95ee\u9898\u53ef\u80fd\u4f1a\u5bfc\u81f4\u9519\u8bef\u6216\u4e71\u7801\u3002\u53ef\u4ee5\u5728\u6253\u5f00\u6587\u4ef6\u65f6\u6307\u5b9a\u7f16\u7801\uff0c\u4f8b\u5982<code>open(&#39;filename.txt&#39;, &#39;r&#39;, encoding=&#39;utf-8&#39;)<\/code>\u3002\u5728\u5904\u7406\u4e0d\u540c\u7f16\u7801\u7684\u6587\u4ef6\u65f6\uff0c\u786e\u4fdd\u4f7f\u7528\u6b63\u786e\u7684\u7f16\u7801\u683c\u5f0f\uff0c\u8fd9\u6837\u53ef\u4ee5\u907f\u514d\u8bfb\u53d6\u9519\u8bef\u3002\u5efa\u8bae\u5728\u8bfb\u53d6\u6587\u4ef6\u65f6\u5148\u68c0\u67e5\u6587\u4ef6\u7684\u7f16\u7801\uff0c\u786e\u4fdd\u80fd\u591f\u6b63\u786e\u89e3\u7801\u6587\u4ef6\u5185\u5bb9\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"\u8981\u627e\u5230\u6587\u4ef6\u7684\u6700\u540e\u4e00\u884c\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u65b9\u6cd5\uff1a\u4f7f\u7528readlines()\u65b9\u6cd5\u8bfb\u53d6\u6240\u6709\u884c\u3001\u4f7f\u7528seek()\u548ctell( 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