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Automation & scripting

CLI tools, scheduled jobs, filesystem tasks, and glue scripts that save time.

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Automation & scripting easy

How to Build an argparse CLI That Filters File Lines by Keyword in Python

This Python script is a command-line tool built with argparse that reads a text file and prints only the lines that contain (or don't contain) a given keyword.

argparse cli filter
Python 
import argparse
import sys

def main():
    parser = argparse.ArgumentParser(description="Filter lines from a file by keyword.")
    parser.add_argument("input", type=str, help="File to read")
    parser.add_argument("keyword", type=str, help="Keyword to filter lines")
    parser.add_argument("--contains", action="sto…
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