我需要在 csv 列中获取值的计数（分组）答案

【问题标题】：I need to get a count of values (grouped) in a csv column我需要在 csv 列中获取值的计数（分组）
【发布时间】：2011-01-06 01:22:36
【问题描述】：

我需要计算第一列的值。这些 ID 可能存在也可能不存在于我收到的任何给定 .csv 文件中。因此，我需要遍历 .csv 文件，查看第一列，如果它不存在，则将其添加到保存数组 ($PWSs) 中，或者如果我已经添加它，则增加此保存数组中的计数。

我有第一个循环使用 fgetcsv()..这适用于破解文件：

$PWSs = array();

$handle2 = fopen ($uploadfileandpath,"r");
while ($field2array = fgetcsv ($handle2, 130000, ",")) 
{
    // Here is where I would add value or increment $PWSs array
    while (?)
    {
        if ($field2array[0] != ?)
        {
            // Add or increment
        }
    }
}

这是实际数据。第一列有公共供水系统的 ID。我需要数一数。

"00513","08/13/2009","090834311A","R","4","OR1000x6","N","N","E",,1,".73","COLILERT"
"00513","08/13/2009","090834312A","R","39","OR1000x6","N","N","E",,1,".35","COLILERT"
"00154","08/13/2009","090835401A","R","300 Falls Road","OR100016","N","N","E",,1,".10","COLILERT"
"95343","08/13/2009","090835601A","R","Room 1 Sink","OR1000x6","N","N","E",,1,,"COLILERT"
"94585","08/14/2009","090837701A","R","Kitchen","OR1000x6","N","N","E",,1,,"COLILERT"
"94704","08/14/2009","090837801A","R","Outside Tap","OR1000x6","N","N","E",,1,,"COLILERT"
"01430","08/14/2009","090838201A","R","100 Deer Park Ln OT","OR1000x6","N","N","E",,1,,"COLILERT"
"00625","08/14/2009","090839001A","R","Dano and N Rose","OR100016","N","N","E",,1,".35","COLILERT"
"00405","08/17/2009","090840301A","R","Westmont Drive","OR100016","N","N","E",,1,".28","COLILERT"
"01031","08/17/2009","090840401A","R","Unit 2 Faucet","OR100016","N","N","E",,1,,"COLILERT"
"00625","08/17/2009","090840601A","R","Luman Road","OR1000x6","N","N","E",,1,".35","COLILERT"
"00513","08/17/2009","090841001A","R","40","OR1000x6","N","N","E",,1,".18","COLILERT"
"00513","08/17/2009","090841002A","R","10","OR1000x6","N","N","E",,1,".16","COLILERT"

【问题讨论】：

标签： php arrays csv count grouping

【解决方案1】：

$fh = fopen('file.csv', 'rb');

$PWS = array();
while($row = fgetcsv($fh)) {
    $PWS[$row[0]]++;
}

基本上，它将使用第一列值作为键填充 PWS，并在它们出现时递增它们。之后，鉴于您上面的示例 csv，您最终会得到

$PWS = array(
    '00513' => 4
    '00154' => 1
    '95343' => 1
    '94585' => 1
etc...
);

【讨论】：

感谢 Marc B。感谢您的这段代码有效，但我也得到了一个未定义的索引：$fh = fopen ($uploadfileandpath,"r"); $PWSs = 数组（）；而($row = fgetcsv($fh,130000,",")) { $PWSs[$row[0]]++; //此行为每个新值返回一个未定义的索引（它仍然会添加它们） } foreach($PWSs as $key => $value) { print "$key: $value
"; } fclose($fh);
我上面的评论不太可读。这是得到“未定义索引”错误的一行。（我无法更改错误报告级别）：$PWSs[$row[0]]++;
好吧，我放弃了聪明，我很聪明。我把它放在页面顶部以避免 UNDEFINED INDEX NOTICE: error_reporting(E_ALL ^ E_NOTICE);
您可以在增量之前执行 if (!isset($PWSs[$key[0]]) { $PWSs[$key[0]] = 0}
@Marc 请编辑您的答案，因此研究人员无需阅读 cmets 即可获得最佳实践。

【解决方案2】：

function get_pws()
{
    $PWSs = array();

    $handle2 = fopen ($uploadfileandpath,"r");
    while ($field2array = fgetcsv ($handle2, 130000, ",")) 
    {
        if(!in_array($field2array[0], $PWSs))
        {
            array_push($PWSs, array('key'=>$field2array[0], 'count'=>1));
        }
        else
        {
            foreach($PWSs as &$PWS)
            {
                if($PWS['key'] == $field2array[0])
                {
                    ++$PWS['count'];
                }
            }
        }
    }

    return $PWSs;
}

我还没有实际运行和测试过这个脚本，所以希望它可以工作，并且它就是你要找的东西；）

编辑：感谢您指出 dq。同样，我还没有测试过它（不是在安装了 PHP 的机器上），所以希望它仍然有效（如果它首先有效）：P

【讨论】：

澄清一下，这会计算有多少不同的唯一 ID，而不仅仅是包含多少行包含 ID。

【解决方案3】：

您只需要一个 while 循环。您的外部 while 循环将在遇到 eof 时停止，因为 fgetcsv() 将返回 FALSE。

然后只需测试该列是否为 NULL 或 "" 为空字符串。如果给定数组中不存在该列，则应使用 isset() 确保它首先存在于条件中。

【讨论】：