Question

I have an input CSV file with a column containing information similar to the sample below:

805265
995874
805674
984654
332574
339852

I’d like to extract unique values into a array based on the leading two characters, so using the above sample my result would be:

80, 99, 98, 33

How might I achieve this using PowerShell?

Answer 1

I’d use the Group-Object cmdlet (alias group) for this:

Import-Csv foo.csv | group {$_.ColumnName.Substring(0, 2)}

Count Name                      Group
----- ----                      -----
    2 80                        {805265, 805674}
    1 99                        {995874}
    1 98                        {984654}
    2 33                        {332574, 339852}