Retrieve S3 filenames, group by 3 digit number with related images in series then split series into columns and new group into new row

Question

I'm attempting to use a CSV to bulk upload listings however the image urls are in columns.

I'm using Amazon S3 to host the images and PowerShell to retrieve the keys of each file. However I am unsure how to group by their related files and then use something like text to columns to split?

The files have a consistent naming structure:

C2-123-1.JPG
C2-123-2.JPG
C2-123-3.JPG
C3-333-1.JPG
C3-333-2.JPG

In the example above C2-123 has three photos, C2-333 has only two so I'm looking to receive an outcome like below.

|Image Link 1|  Image Link 2|   Image Link 3|   Image Link 4|
|C2-123-1.JPG|  C2-123-2.JPG|   C2-123-3.JPG|               |
|C3-333-1.JPG|  C3-333-2.JPG|               |               |

Answer 1

This should work, you should replace $data for the output you get from AWS.

• Using $data for testing:

$data = @'
C2-123-1.JPG
C2-123-2.JPG
C2-123-3.JPG
C3-333-1.JPG
C3-333-2.JPG
C3-333-4.JPG
C3-333-999.JPG
C3-456-2.JPG
C3-111-2.JPG
C3-999-4.JPG
'@ -split '\r?\n'

• First, group by the numbers between the last - and the .jpg extension:

Count Name    Group
----- ----    -----
    2 1       {C2-123-1.JPG, C3-333-1.JPG}
    4 2       {C2-123-2.JPG, C3-333-2.JPG, C3-456-2.JPG, C3-111-2.JPG}
    1 3       {C2-123-3.JPG}
    2 4       {C3-333-4.JPG, C3-999-4.JPG}
    1 999     {C3-333-999.JPG}

• Then get the maximum number of elements of the Group arrays
• Lastly, use a while loop with $max as reference to cast [pscustomobject]

# Group the files
$groups = $data | Group-Object {

    [regex]::Match(
        $_,
        '(?i)(?<=\d-)(?<imagenum>\d+)\.jpg$'
    ).Groups['imagenum'].Value

}

# Determine max number of elements
$max = $groups.Count | Measure-Object -Maximum
$index = 0

# Construct the object
$result = while($max.Maximum--)
{
    $out = [ordered]@{}
    $groups.ForEach({
        $key = 'Image Link {0}' -f $_.Name
        $out[$key] = $_.Group[$index]
    })

    [pscustomobject]$out
    $index++
}

Result would be:

PS /> $result | Format-Table


Image Link 1 Image Link 2 Image Link 3 Image Link 4 Image Link 999
------------ ------------ ------------ ------------ --------------
C2-123-1.JPG C2-123-2.JPG C2-123-3.JPG C3-333-4.JPG C3-333-999.JPG
C3-333-1.JPG C3-333-2.JPG              C3-999-4.JPG 
             C3-456-2.JPG                           
             C3-111-2.JPG    

To see the regex explanation you can use https://regex101.com/r/kARr39/1