How to Filter Data from Multiple CSV Files Using PowerShell

Discover a simple PowerShell script to extract rows with consecutive matching values from over 1000 CSV files.
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How to Filter Data from Multiple CSV Files Using PowerShell

If you're dealing with multiple CSV files and you need to extract rows containing consecutive matching values, you've come to the right place. In this post, we will walk through a practical PowerShell solution for filtering such data from over 1,000 CSV files efficiently.

The Problem: Filtering Consecutive Rows by Matching Values

Imagine you have a folder filled with over 1,000 CSV files, each with the following simplified structure:

[[See Video to Reveal this Text or Code Snippet]]

You need to keep rows that have consecutive matching values in the RecvByts column. For example, from the sample data provided, the output should look like this:

[[See Video to Reveal this Text or Code Snippet]]

The Solution: PowerShell Script for Filtering

To achieve this, we will write a PowerShell script that will:

Import the CSV file.

Compare each record with the previous one.

Write matching consecutive rows into a new collection.

Step-by-Step Breakdown

Let's get into the script and understand how to filter the data effectively.

Step 1: Define the Parameters

We will begin by defining the parameters for our function. It will take the path to a CSV file as input.

[[See Video to Reveal this Text or Code Snippet]]

Step 2: Import the CSV and Initialize Variables

Next, we will import the CSV file and set up two variables: one for storing the previous record and another for tracking whether a match has been found.

[[See Video to Reveal this Text or Code Snippet]]

Step 3: Process Each Record

In the processing step, we will loop through each record in the CSV. If the current record's RecvByts matches the previous record's RecvByts, we add the previous record to our output and set the match indicator.

[[See Video to Reveal this Text or Code Snippet]]

Step 4: Output the Results

Finally, we check if a match was found during the last iteration, and if so, we output that record.

[[See Video to Reveal this Text or Code Snippet]]

Running the Script

[[See Video to Reveal this Text or Code Snippet]]

You will get an output highlighting the rows that have consecutive matching values in the RecvByts column, such as this:

[[See Video to Reveal this Text or Code Snippet]]

1 19/Mar/2024:02:50:17 3614
2 19/Mar/2024:02:50:18 3614
4 19/Mar/2024:02:50:20 166293
5 19/Mar/2024:02:50:20 166293
6 19/Mar/2024:02:50:20 166293
9 19/Mar/2024:02:50:21 146236
10 19/Mar/2024:02:50:21 146236

[[See Video to Reveal this Text or Code Snippet]]