如何从多个文件中删除最后两列 - 代码不起作用

Question

我正在尝试从目录中的多个文件中删除最后 2 列。这段代码接近我需要的，但它只是删除最后一列（包括HEADER7）。它还会删除HEADER6但第 6 列中的所有数据保持不变。最后一列包含每个文件的文件名。文件以逗号分隔。

$InputFolder = '.'
$OutputFolder = '.'

Get-ChildItem $InputFolder -Filter *.* |
where {-not $_.psiscontainer} |
foreach {
$FileName = $_.Name
$BaseName = $_.Basename
$data = Get-Content $_ -ReadCount 0
$($data[0]) -replace  ",HEADER6",'' -replace ",HEADER7",'' | Set-Content $OutputFolder$FileName 
$data[1..($data.Length -1)] -replace ",$HEADER6",'' -replace ",$BaseName",'' | Add-Content $OutputFolder$FileName
 }

文件示例

HEADER1,HEADER2,HEADER3,HEADER4,HEADER5,HEADER6,HEADER7
22.1,34.02,12.00,23.44,123.33,12.34,FILE1
25.1,30.22,12.55,21.40,13.03,15.31,FILE1
15.51,10.24,11.54,11.50,12.13,17.14,FILE1

...

Answer 1

看看这是否更快：

$InputFolder = '.'
$OutputFolder = '.'

Get-ChildItem $InputFolder -Filter *.* |
where {-not $_.psiscontainer} |
foreach {
$FileName = $_.Name
(Get-Content $_ -ReadCount 0 ) -replace ',[^,]+,[^,]+$' |
Set-Content $OutputFolder$FileName 
 }

Answer 2

你可以尝试字符串操作。如果您有大文件，它应该比import-/export-csv更快：

Get-ChildItem $InputFolder -Filter *.* |
Where-Object {-not $_.psiscontainer} |
ForEach-Object {
    $FileName = $_.Name
    $text = [System.IO.File]::ReadAllLines($_.FullName)
    $modifiedtext = foreach($line in $text) {
        $line -replace '(?<=S*?,S*?,S*?,S*?,S*?),.*'
    }
    $modifiedtext | Set-Content $OutputFolder$FileName
    #The line below might be even faster.
    #[System.IO.File]::WriteAllLines(((Resolve-Path $OutputFolder$FileName).Path), $modifiedtext)
}

Answer 3

您可以导入 CSV，选择要保留的列并直接导出

Import-Csv c:TEMPtest.csv | Select-Object -property HEADER1,HEADER2,HEADER3,HEADER4,HEADER5 | Export-Csv -NoTypeInformation c:temptest2.csv