我正在尝试找出一种使用Import-CSV (powershell)将值放入csv文件数组的更有效的方法。问题是,其中一些文件有几十万行,将此脚本与其他代码行一起运行似乎是一个很大的瓶颈。你们有什么建议可以让这段代码更高效更快吗?
foreach($csv in $csvfiles)
{
$csvname = $csv.name;
$paygroup = $csvname.substring(4,3);
$batch = $csvname.substring(14,4);
write-host "Writing $csvname";
$csvimportdata = Import-CSV $CurrentPath"\$csvname";
foreach($record in $csvimportdata)
{
$record.chartfield1 = $paygroup;
$record.chartfield2 = $batch;
$record.chartfield3 = $record.line_descr.substring(0,6);
}
$csvimportdata | Export-CSV $CurrentPath"\$csvname" -NoTypeInformation
};发布于 2015-06-08 22:30:15
如果您的CSV很大,那么加载到内存中可能不是一个好主意。这样如何:
foreach($csv in $csvfiles)
{
$csvname = $csv.name
$paygroup = $csvname.substring(4,3)
$batch = $csvname.substring(14,4)
write-host "Writing $csvname"
Get-Content $CurrentPath"\$csvname" -Readcount 1 | % {
# Regex below assumes a three column CSV
$_ -replace '^([^,]+,[^,]+,[^,]{6}).*$', '$1'
} | Set-Content $CurrentPath"\$csvname"
}https://stackoverflow.com/questions/30677211
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