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28. CSV parsing

Note

The below information is extensively based in information taken from the PowerShell® Notes for Professionals book. I plan to extend this information based on my day to day usage of the language.

28.1: Basic usage of Import-Csv

Given the following CSV-file

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String,DateTime,Integer
First, 2016 - 12 - 01T12:00:00, 30
Second, 2015 - 12 - 01T12:00:00, 20
Third, 2015 - 12 - 01T12:00:00, 20

One can import the CSV rows in PowerShell objects using the Import-Csv command

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$listOfRows = Import-Csv .\example.csv
$listOfRows
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String DateTime Integer
------ -------- -------
First 2016 - 12 - 01T12:00:00 30
Second 2015 - 11 - 03T13:00:00 20
Third 2015 - 12 - 05T14:00:00 20
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Write-Host $row[ 0 ].String1
Third

28.2: Import from CSV and cast properties to correct type

By default, Import-CSV imports all values as strings, so to get DateTime- and integer-objects, we need to cast or parse them.

Using Foreach-Object :

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$listOfRows = Import-Csv .\example.csv
$listOfRows | ForEach-Object {
  #Cast properties
  $_.DateTime = [datetime]$_.DateTime
  $_.Integer = [int]$_.Integer
  #Output object
  $_
}

Using calculated properties:

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$listOfRows = Import-Csv .\example.csv
$listOfRows | Select-Object String,
  @{name="DateTime";expression={ [datetime]$_.DateTime }},
  @{name="Integer";expression={ [int]$_.Integer }}

Output:

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String DateTime Integer
------ -------- -------
First 01.12.2016 12:00:00 30
Second 03.11.2015 13:00:00 20
Third 05.12.2015 14:00:00 20