powershell transpose and keep only one set of headers - excel

Question

I have a data set that looks like below
headers data
ip 192.168.1.1
netmask 255.255.255.0
description class C
ip 172.20.1.1
netmask 255.255.0.0
description class B
ip 10.0.0.1
netmask 255.255.255.0
description class A
How can I turn that into my expected output of:
ip netmask description
192.168.1.1 255.255.255.0 class C
172.20.1.1 255.255.0.0 class B
10.0.0.1 255.0.0.0 class A
Currently I am importing this data from CSV like below:
$data = import-csv .\data.txt -headers headers,data
If there is an easy way to do this in excel that would be fantastic as well.
Any assistance would be great. Thank you.

Answer 1

The previous answer didn't use the data specified in the question, this one does. It's also fully commented to explain what it does. Below the code is a rundown of how it works:
$newrow = #{} # newrow contains the values on an output row at any given time
$newtable = [System.Collections.ArrayList]#() # newtable contains the final output
# Loop through each row in the input data, assign oldrow to the current row
foreach($oldrow in $data) {
# If the output row already has an ip, netmask or description, then start a new row (hashtable) and add the current row (hashtable) to output
if ($newrow[$oldrow.headers] -ne $null) {
Write-Host "$($oldrow.headers) Already found. Adding new row to output" -ForegroundColor Green
# Add the current row to the target object
[void]$newtable.Add($(New-Object PSObject -Property $newrow))
# Create a new empty row (hashtable)
$newrow = #{}
}
# For each iteration, keep adding data
Write-Host "Adding new entry for $($oldrow.headers)"
$newrow[$oldrow.headers] = $oldrow.data
}
# The final row is not added to the table within the loop, so it must be added here
Write-Host "Loop finished, adding final row to output" -ForegroundColor Green
[void]$newtable.Add($(New-Object PSObject -Property $newrow))
$newtable | select ip,netmask,description
Assumption
Upon encountering a record with the same header value, a new row is required. Until that point, records should be added to the same row, with the header value providing the new column name.
Process
Set up a hashtable called $newrow.
Set up an ArrayList called $newtable. ArrayLists are more flexible than standard Arrays as they have an Add() method.
Iterate through the data using a foreach loop
Start with an if statement that deals with finding a record with a column that we have already assigned. At this point fire a message using Write-Host, add the old row and set up the new row. On the first iteration of the foreach loop, this always evaluates to false as the hashtable is empty.
In the block outside the if condition, keep adding values to the hashtable.
At the end, add the final row and then use select-object to print the output in the right order.

Answer 2

#Import data
$data = Import-Csv .\data.txt -headers headers,data
$data | FT -AutoSize
#Remove the first line
get-content $data | select -Skip 1 | set-content "$data-temp"
move "$data-temp" $data -Force
#Convert the table
$Duration = Measure-Command {
$b = #()
foreach ($Property in $data.Property | Select -Unique) {
$Props = [ordered]#{ Property = $Property }
foreach ($Server in $data.Server | Select -Unique){
$Value = ($data.where({ $_.Server -eq $Server -and
$_.Property -eq $Property })).Value
$Props += #{ $Server = $Value }
}
$b += New-Object -TypeName PSObject -Property $Props
}
}
Write-Host "Finished transposing " -ForegroundColor Green -NoNewline
Write-Host "$(($data | Get-Member -MemberType Properties).count)/$($data.Count)" -ForegroundColor Yellow -NoNewline
Write-Host " columns/rows into " -ForegroundColor Green -NoNewline
Write-Host "$(($b | Get-Member -MemberType Properties).count)/$($b.Count)" -ForegroundColor Yellow -NoNewline
Write-Host " columns/rows in " -ForegroundColor Green -NoNewline
Write-Host $Duration.Milliseconds -ForegroundColor Yellow -NoNewline
Write-Host " Milliseconds" -ForegroundColor Green
$b | FT -AutoSize
$b | Out-GridView
$b | Export-Csv .\newData.csv -NoTypeInformation
newData.csv should look as you expected, if not, let me know again.