csv文件解读

小鱼儿 2022-07-14 10:39 273阅读 0赞

### 基本规则 ###

CSV格式是分隔的数据格式，有字段/列分隔的逗号字符和记录/行分隔换行符。字段包含特殊字符(逗号，换行符，或双引号)，必须以双引号括住。行内包含一个项目是空字符串，可以以双引号括住。字段的值包含双引号时，要双写这个双引号（就像把一个双引号当做转义符一样）。CSV文件格式并不需要特定的字符编码，字节顺序，或行终止格式。

*  每个记录是一个行终止了换行符( [ASCII码][ASCII]/低频= 0×0A)或回车换行符和一双(ASCII码/ CRLF = 0×0D0×0A)，然而，线路中断可以嵌入。
 *  字段用逗号分隔（虽然地点在逗号作为小数点，分号是用来代替作为定界符）

1997,Ford,E350

*  在某些的CSV实施，领导和尾随空格或制表符，毗邻逗号，装饰。这种做法是有争议的 ， 实际上是明文禁止的RFC 4180，其中规定，“被认为是空间的一个组成部分领域 ， 而不应被忽视。”
 *  各领域内的嵌入式逗号必须存放在双引号字符。
 *  各领域内的嵌入式双引号字符必须是封闭的双引号字符，每一个嵌入式双引号字符必须用一对双引号字符。
 *  各领域内的嵌入式换行符必须封闭在双引号字符。
 *  领域的前导或尾随空格内必须封闭双引号字符。 (见评论领导和尾随 [空格][Link 1]以上。)
 *  字段可能永远是封闭的双引号字符，是否有必要或没有。
 *  第一条记录中的CSV文件中可能包含列名的每个领域。

### 举例说明 ###

<table style="border-spacing:0px; border-collapse:collapse; margin:5px 0px; word-wrap:break-word; word-break:break-all; font-size:12px; line-height:22px; color:rgb(0,0,0); font-family:arial,宋体,sans-serif"> 
 <tbody> 
  <tr> 
   <td style="margin:0px; padding:2px 10px; line-height:22px; height:22px; border:1px solid rgb(230,230,230)"> 
    <div style="word-wrap:break-word; color:rgb(51,51,51); margin:0px; line-height:24px; zoom:1; height:auto">
      年 
    </div> </td> 
   <td style="margin:0px; padding:2px 10px; line-height:22px; height:22px; border:1px solid rgb(230,230,230)"> 
    <div style="word-wrap:break-word; color:rgb(51,51,51); margin:0px; line-height:24px; zoom:1; height:auto">
      制造商 
    </div> </td> 
   <td style="margin:0px; padding:2px 10px; line-height:22px; height:22px; border:1px solid rgb(230,230,230)"> 
    <div style="word-wrap:break-word; color:rgb(51,51,51); margin:0px; line-height:24px; zoom:1; height:auto">
      型号 
    </div> </td> 
   <td style="margin:0px; padding:2px 10px; line-height:22px; height:22px; border:1px solid rgb(230,230,230)"> 
    <div style="word-wrap:break-word; color:rgb(51,51,51); margin:0px; line-height:24px; zoom:1; height:auto">
      说明 
    </div> </td> 
   <td style="margin:0px; padding:2px 10px; line-height:22px; height:22px; border:1px solid rgb(230,230,230)"> 
    <div style="word-wrap:break-word; color:rgb(51,51,51); margin:0px; line-height:24px; zoom:1; height:auto">
      价值 
    </div> </td> 
  </tr> 
  <tr> 
   <td style="margin:0px; padding:2px 10px; line-height:22px; height:22px; border:1px solid rgb(230,230,230)"> 
    <div style="word-wrap:break-word; color:rgb(51,51,51); margin:0px; line-height:24px; zoom:1; height:auto">
      1997 
    </div> </td> 
   <td style="margin:0px; padding:2px 10px; line-height:22px; height:22px; border:1px solid rgb(230,230,230)"> 
    <div style="word-wrap:break-word; color:rgb(51,51,51); margin:0px; line-height:24px; zoom:1; height:auto">
      Ford 
    </div> </td> 
   <td style="margin:0px; padding:2px 10px; line-height:22px; height:22px; border:1px solid rgb(230,230,230)"> 
    <div style="word-wrap:break-word; color:rgb(51,51,51); margin:0px; line-height:24px; zoom:1; height:auto">
      E350 
    </div> </td> 
   <td style="margin:0px; padding:2px 10px; line-height:22px; height:22px; border:1px solid rgb(230,230,230)"> 
    <div style="word-wrap:break-word; color:rgb(51,51,51); margin:0px; line-height:24px; zoom:1; height:auto">
      ac, abs, moon 
    </div> </td> 
   <td style="margin:0px; padding:2px 10px; line-height:22px; height:22px; border:1px solid rgb(230,230,230)"> 
    <div style="word-wrap:break-word; color:rgb(51,51,51); margin:0px; line-height:24px; zoom:1; height:auto">
      3000.00 
    </div> </td> 
  </tr> 
  <tr> 
   <td style="margin:0px; padding:2px 10px; line-height:22px; height:22px; border:1px solid rgb(230,230,230)"> 
    <div style="word-wrap:break-word; color:rgb(51,51,51); margin:0px; line-height:24px; zoom:1; height:auto">
      1999 
    </div> </td> 
   <td style="margin:0px; padding:2px 10px; line-height:22px; height:22px; border:1px solid rgb(230,230,230)"> 
    <div style="word-wrap:break-word; color:rgb(51,51,51); margin:0px; line-height:24px; zoom:1; height:auto">
      Chevy 
    </div> </td> 
   <td style="margin:0px; padding:2px 10px; line-height:22px; height:22px; border:1px solid rgb(230,230,230)"> 
    <div style="word-wrap:break-word; color:rgb(51,51,51); margin:0px; line-height:24px; zoom:1; height:auto">
      Venture "Extended Edition" 
    </div> </td> 
   <td style="margin:0px; padding:2px 10px; line-height:22px; height:22px; border:1px solid rgb(230,230,230)"> &nbsp;</td> 
   <td style="margin:0px; padding:2px 10px; line-height:22px; height:22px; border:1px solid rgb(230,230,230)"> 
    <div style="word-wrap:break-word; color:rgb(51,51,51); margin:0px; line-height:24px; zoom:1; height:auto">
      4900.00 
    </div> </td> 
  </tr> 
  <tr> 
   <td style="margin:0px; padding:2px 10px; line-height:22px; height:22px; border:1px solid rgb(230,230,230)"> 
    <div style="word-wrap:break-word; color:rgb(51,51,51); margin:0px; line-height:24px; zoom:1; height:auto">
      1999 
    </div> </td> 
   <td style="margin:0px; padding:2px 10px; line-height:22px; height:22px; border:1px solid rgb(230,230,230)"> 
    <div style="word-wrap:break-word; color:rgb(51,51,51); margin:0px; line-height:24px; zoom:1; height:auto">
      Chevy 
    </div> </td> 
   <td style="margin:0px; padding:2px 10px; line-height:22px; height:22px; border:1px solid rgb(230,230,230)"> 
    <div style="word-wrap:break-word; color:rgb(51,51,51); margin:0px; line-height:24px; zoom:1; height:auto">
      Venture "Extended Edition, Very Large" 
    </div> </td> 
   <td style="margin:0px; padding:2px 10px; line-height:22px; height:22px; border:1px solid rgb(230,230,230)"> &nbsp;</td> 
   <td style="margin:0px; padding:2px 10px; line-height:22px; height:22px; border:1px solid rgb(230,230,230)"> 
    <div style="word-wrap:break-word; color:rgb(51,51,51); margin:0px; line-height:24px; zoom:1; height:auto">
      5000.00 
    </div> </td> 
  </tr> 
  <tr> 
   <td style="margin:0px; padding:2px 10px; line-height:22px; height:22px; border:1px solid rgb(230,230,230)"> 
    <div style="word-wrap:break-word; color:rgb(51,51,51); margin:0px; line-height:24px; zoom:1; height:auto">
      1996 
    </div> </td> 
   <td style="margin:0px; padding:2px 10px; line-height:22px; height:22px; border:1px solid rgb(230,230,230)"> 
    <div style="word-wrap:break-word; color:rgb(51,51,51); margin:0px; line-height:24px; zoom:1; height:auto">
      Jeep 
    </div> </td> 
   <td style="margin:0px; padding:2px 10px; line-height:22px; height:22px; border:1px solid rgb(230,230,230)"> 
    <div style="word-wrap:break-word; color:rgb(51,51,51); margin:0px; line-height:24px; zoom:1; height:auto">
      Grand Cherokee 
    </div> </td> 
   <td style="margin:0px; padding:2px 10px; line-height:22px; height:22px; border:1px solid rgb(230,230,230)"> 
    <div style="word-wrap:break-word; color:rgb(51,51,51); margin:0px; line-height:24px; zoom:1; height:auto">
      MUST SELL! 
     <br> 　　air, moon roof, loaded 
    </div> </td> 
   <td style="margin:0px; padding:2px 10px; line-height:22px; height:22px; border:1px solid rgb(230,230,230)"> 
    <div style="word-wrap:break-word; color:rgb(51,51,51); margin:0px; line-height:24px; zoom:1; height:auto">
      4799.00 
    </div> </td> 
  </tr> 
 </tbody> 
</table>

上面表格内容若以CSV格式表示就会像下列：

年,制造商,型号,说明,价值

1997,Ford,E350,"ac, abs, moon",3000.00  
　　1999,Chevy,"Venture ""Extended Edition""","",4900.00  
　　1999,Chevy,"Venture ""Extended Edition, Very Large""","",5000.00  
　　1996,Jeep,Grand Cherokee,"MUST SELL!

air, moon roof, loaded",4799.00

以上这个CSV的例子说明了:

*  包含逗号, 双引号, 或是换行符的字段必须放在引号内.
 *  字段内部的引号必须在其前面增加一个引号来实现文字引号的转码.
 *  分隔符逗号前后的空格  可能不会 被修剪掉. 这是RFC 4180的要求.
 *  元素中的换行符将被保留下来. \[1\]

[ASCII]: http://baike.baidu.com/view/812.htm
[Link 1]: http://baike.baidu.com/subview/533126/8068137.htm