How to split a line into multiple lines?

Question

I have a CSV file which looks something like this:

Column1,Column2,Column3
John,Smith,\"AA, AH, CA, NI, PB\"
Regin         


        

Answer 1

Use Import-Csv to read the input file, then split the third column and create new output lines for each resulting element:

Import-Csv 'C:\path\to\input.csv' | ForEach-Object {
  foreach ($value in ($_.Column3 -split ', ')) {
    $_ | Select-Object -Exclude Column3 -Property *,@{n='Column3';e={$value}}
  }
} | Export-Csv 'C:\path\to\output.csv' -NoType

The Select-Object construct replaces the existing property Column3 with a new property Column3 that contains only a single value.