PowerShell Import-CSV, For Each Item, Delete String After Symbol -

if have list this:

user1.xxxx user2.xxxxx user3.xxx 

how can create each loop , delete after period? how delete before well? have basics written, , tried few misguided attempts manipulating .substring etc...:

$allusers = import-csv -path "c:\folder1\all user.csv" $allusers | foreach {  } | export-csv -path "c:\folder1\removed.csv" 

the easiest way in case use split method:

$allusers = get-content somepath | foreach {     $_.split('.')[0] } | set-content somepath 

[0] taking first element array of elements created split, in case there 2 elements, before dot , after dot. take after dot [1] instead of [0].
also, not want use import-csv since in case easier work raw data.

edit: since i'm not sure actual csv looks might want use this:

$data = import-csv somepath $results = @() foreach ($line in $data) {     $line.column_that_needs_editing = $line.column_that_needs_editing.split('.')[0]     $results += $_ }  $results | export-csv someotherpath