<p style="margin-top:5px; margin-bottom:5px; padding-top:0px; padding-bottom:0px; color:rgb(51,51,51); font-family:"Trebuchet MS",Helvetica,Tahoma,宋体,Arial,Verdana,sans-serif; font-size:14px"> 假设CSV文件内容如下：</p>
<pre style="margin-top:0px; margin-bottom:0px; padding:0px; color:rgb(51,51,51); font-size:14px; background-color:rgb(255,255,255)"><code class="hljs" style="margin:15px 0px; padding:0.5em; font-family:Consolas,"Courier New","Lucia Console",monospace,sans-serif; display:block; border:1px solid rgb(204,204,204); background:rgb(253,246,227); overflow-x:auto; color:rgb(101,123,131)">No.,Name,Age,Score
1,Apple,12,98
2,Ben,13,97
3,Celia,14,96
4,Dave,15,95
</code></pre>
<p style="margin-top:5px; margin-bottom:5px; padding-top:0px; padding-bottom:0px; color:rgb(51,51,51); font-family:"Trebuchet MS",Helvetica,Tahoma,宋体,Arial,Verdana,sans-serif; font-size:14px"> 保存为“A.csv“，利用Python自带的 <a href="https://docs.python.org/2/library/csv.html" rel="noopener noreferrer" style="margin:0px; padding:0px; color:rgb(119,153,51); word-break:keep-all" target="_blank">csv模块</a> ，有两种方法可以实现提取其中的一行：</p>
<h4 style="margin:20px 0px 15px; padding:0px; font-size:20px; color:rgb(51,51,51); font-family:"Trebuchet MS",Helvetica,Tahoma,宋体,Arial,Verdana,sans-serif"> 方法一：reader</h4>
<p style="margin-top:5px; margin-bottom:5px; padding-top:0px; padding-bottom:0px; color:rgb(51,51,51); font-family:"Trebuchet MS",Helvetica,Tahoma,宋体,Arial,Verdana,sans-serif; font-size:14px"> 第一种方法使用reader函数，接收一个可迭代的对象（比如csv文件），能返回一个生成器，就可以从其中解析出csv的内容：比如下面的代码可以读取csv的全部内容，以行为单位：</p>
<pre style="margin-top:0px; margin-bottom:0px; padding:0px; color:rgb(51,51,51); font-size:14px; background-color:rgb(255,255,255)"><code class="hljs python" style="margin:15px 0px; padding:0.5em; font-family:Consolas,"Courier New","Lucia Console",monospace,sans-serif; display:block; border:1px solid rgb(204,204,204); background:rgb(253,246,227); overflow-x:auto; color:rgb(101,123,131)"><span class="hljs-keyword" style="margin:0px; padding:0px; color:rgb(133,153,0)">import</span> csv
<span class="hljs-keyword" style="margin:0px; padding:0px; color:rgb(133,153,0)">with</span> open(<span class="hljs-string" style="margin:0px; padding:0px; color:rgb(42,161,152)">'A.csv'</span>,<span class="hljs-string" style="margin:0px; padding:0px; color:rgb(42,161,152)">'rb'</span>) <span class="hljs-keyword" style="margin:0px; padding:0px; color:rgb(133,153,0)">as</span> csvfile:
reader = csv.reader(csvfile)
rows = [row <span class="hljs-keyword" style="margin:0px; padding:0px; color:rgb(133,153,0)">for</span> row <span class="hljs-keyword" style="margin:0px; padding:0px; color:rgb(133,153,0)">in</span> reader]
<span class="hljs-keyword" style="margin:0px; padding:0px; color:rgb(133,153,0)">print</span> rows
</code></pre>
<p style="margin-top:5px; margin-bottom:5px; padding-top:0px; padding-bottom:0px; color:rgb(51,51,51); font-family:"Trebuchet MS",Helvetica,Tahoma,宋体,Arial,Verdana,sans-serif; font-size:14px"> 得到：</p>
<pre style="margin-top:0px; margin-bottom:0px; padding:0px; color:rgb(51,51,51); font-size:14px; background-color:rgb(255,255,255)"><code class="hljs json" style="margin:15px 0px; padding:0.5em; font-family:Consolas,"Courier New","Lucia Console",monospace,sans-serif; display:block; border:1px solid rgb(204,204,204); background:rgb(253,246,227); overflow-x:auto; color:rgb(101,123,131)">[['No.', 'Name', 'Age', 'Score'],
['<span class="hljs-number" style="margin:0px; padding:0px; color:rgb(42,161,152)">1</span>', 'Apple', '<span class="hljs-number" style="margin:0px; padding:0px; color:rgb(42,161,152)">12</span>', '<span class="hljs-number" style="margin:0px; padding:0px; color:rgb(42,161,152)">98</span>'],
['<span class="hljs-number" style="margin:0px; padding:0px; color:rgb(42,161,152)">2</span>', 'Ben', '<span class="hljs-number" style="margin:0px; padding:0px; color:rgb(42,161,152)">13</span>', '<span class="hljs-number" style="margin:0px; padding:0px; color:rgb(42,161,152)">97</span>'],
['<span class="hljs-number" style="margin:0px; padding:0px; color:rgb(42,161,152)">3</span>', 'Celia', '<span class="hljs-number" style="margin:0px; padding:0px; color:rgb(42,161,152)">14</span>', '<span class="hljs-number" style="margin:0px; padding:0px; color:rgb(42,161,152)">96</span>'],
['<span class="hljs-number" style="margin:0px; padding:0px; color:rgb(42,161,152)">4</span>', 'Dave', '<span class="hljs-number" style="margin:0px; padding:0px; color:rgb(42,161,152)">15</span>', '<span class="hljs-number" style="margin:0px; padding:0px; color:rgb(42,161,152)">95</span>']]
</code></pre>
<p style="margin-top:5px; margin-bottom:5px; padding-top:0px; padding-bottom:0px; color:rgb(51,51,51); font-family:"Trebuchet MS",Helvetica,Tahoma,宋体,Arial,Verdana,sans-serif; font-size:14px"> 要提取其中第二行，可以用下面的代码：</p>
<pre style="margin-top:0px; margin-bottom:0px; padding:0px; color:rgb(51,51,51); f |
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