将 CSV 列转换为行

Question

我正在尝试创建一个将 CSV 文件从列转换为行的 PowerShell 脚本。

我发现了相反的例子（将基于行的 CSV 转换为列），但我没有发现列到行的任何内容。我的问题是我不知道我将拥有多少列。我尝试调整行到列到列到行，但没有成功。

$a = Import-Csv "input.csv"
$a | FT -AutoSize

$b = @()
foreach ($Property in $a.Property | Select -Unique) {
    $Props = [ordered]@{ Property = $Property }
    foreach ($Server in $a.Server | Select -Unique){ 
        $Value = ($a.where({ $_.Server -eq $Server -and 
                    $_.Property -eq $Property })).Value
        $Props += @{ $Server = $Value }
    }
    $b += New-Object -TypeName PSObject -Property $Props
}

$b | FT -AutoSize
$b | Out-GridView
$b | Export-Csv "output.csv" -NoTypeInformation 

例如，我的 CSV 可能如下所示：

"ID","DATA1" "12345","11111" "54321","11111" "23456","44444"

或者这个（列数可以变化）：

"ID","DATA1","DATA2","DATA3" "12345","11111","22222","33333" "54321","11111",, "23456","44444","55555",

我希望脚本能像这样转换它：

"ID","数据" "12345","11111" "12345","22222" "12345","33333" "54321","11111" "23456","44444" "23456","55555"

Answer 1

诀窍是查询表的成员以获取列名。一旦你这样做了，剩下的就很简单了：

function Flip-Table ($Table) {

    Process {

        $Row = $_

        # Get all the columns names, excluding the ID field.
        $Columns = ($Row | Get-Member -Type NoteProperty | Where-Object Name -ne ID).Name

        foreach ($Column in $Columns) {

            if ($Row.$Column) {

                $Properties = [Ordered] @{
                    "ID"   = $Row.ID
                    "DATA" = $Row.$Column
                }

                New-Object PSObject -Property $Properties
            }
        }

        # Garbage collection won't kick in until the end of the script, so
        # invoke it every 100 input rows.

        $Count++;

        if (($Count % 100) -eq 0) {
            [System.GC]::GetTotalMemory('forceFullCollection') | out-null
        }
    }
}

Import-Csv input.csv | Flip-Table | Export-Csv -NoTypeInformation output.csv

Answer 2

嗯，这是我的。我不像其他人那么花哨：

$in = Get-Content input.csv | Select -Skip 1
$out = New-Object System.Collections.ArrayList
foreach($row in $in){
    $parts = $row.Split(',')
    $id = $parts[0]
    foreach($data in $parts[1..$parts.Count]){
        if($data -ne '' -AND $data -ne $null){
            $temp = New-Object PSCustomObject -Property @{'ID' = $id;
                                                        'Data' = $data}
            $out.Add($temp) | Out-Null
        }
    }

}
$out | Export-CSV output.csv -NoTypeInformation

Answer 3

你可以这样做

# Convert csv to object
$csv = ConvertFrom-Csv @"
"ID","DATA1","DATA2","DATA3"
"12345","11111","22222","33333"
"54321","11111",,
"23456","44444","55555"
"@

# Ignore common members and the ID property
$excludedMembers = @(
    'GetHashCode',
    'GetType',
    'ToString',
    'Equals',
    'ID'
)

$results = @()

# Iterate around each csv row
foreach ($row in $csv) {
    $members =  $row | Get-Member
    # Iterate around each member from the 'row object' apart from our 
    # exclusions and empty values
    foreach ($member in $members | 
        Where { $excludedMembers -notcontains $_.Name -and $row.($_.Name)}) {
        # add to array of objects
        $results += @{ ID=$row.ID; DATA=$row.($member.Name)}
    }
}

# Write the csv string
$outstring = "ID,DATA"
$results | foreach { $outstring += "`n$($_.ID),$($_.DATA)" }

# New csv object
$csv = $outstring | ConvertFrom-Csv

可能不是最优雅的解决方案，但应该做你需要的

我留下了一些 cmets 解释它的作用

Answer 4

如果您只想接受有限数量的 DATA 列（例如 5 个），您可以这样做：

ForEach ($i in 1..5) {$CSV | ? {$_."Data$i"} | Select ID, @{N='Data'; E={$_."Data$i"}}}

如果您有无限数量的DATA 列：

ForEach ($Data in ($CSV | Select "Data*" -First 1).PSObject.Properties.Name) {
    $CSV | ? {$_.$Data} | Select ID, @{N='Data'; E={$_.$Data}}
}