Powershell: using Import-CSV to import groups of objects in blocks

Challenge

You have a large CSV file with many objects. You want to work with a subset from the file. You want the subset to be from midway in the file. You want a range such as the 150th object to the 400th object.

You do NOT want just the first or last number of objects.

Solution

Use piping and Select-Object to pull the range of objects you want.

Your file has a collection with 1,000 objects. You want objects 150 to 400.

# Variables:
$StartRange = 150
$EndRange = 400
$SubsetRange = $EndRange - $StartRange
$ImportFileTotal = (Import-CSV .\YourImportFile.csv).Count
$ImportFileEnd = $ImportFileTotal - $StartRange
# Process:
Import-CSV .\YourImportFile.csv |
Select-Object -Last $ImportFileEnd&amp;amp;nbsp; |
Select-Object -First $SubsetRange

How this works

The solution uses successive use of Select-Object and the -First and -Last parameters.

Import-CSV creates an object collection with all the objects from the import file.

The first Select-Object creates a subset of all objects starting with the object at the $StartRange position. All objects prior to the $StartRange object are omitted from the output object

The second Select-Object creates a subset of the first objects up to the $SubsetEndrange. The output object has the number of objects that are within the desired range from the original collection start object to the end object.

Microsoft Documentation-Select-Object