fml - first middle last

fml.py

#!/usr/bin/env python3

# cat life.txt | fml.py -n 10

import sys
import argparse

def process_stream(n):
    lines = []
    for line in sys.stdin:
        lines.append(line.rstrip())
    
    total_lines = len(lines)
    
    if total_lines <= 3 * n:
        for line in lines:
            print(line)
    else:
        for i in range(n):
            print(lines[i])
        print("...")
        
        middle_start = (total_lines - n) // 2
        for i in range(middle_start, middle_start + n):
            print(lines[i])
        print("...")
        
        for i in range(total_lines - n, total_lines):
            print(lines[i])

if __name__ == "__main__":
    parser = argparse.ArgumentParser(description="Print first, middle, and last N lines of input")
    parser.add_argument("-n", type=int, default=10, help="Number of lines to print for each section")
    args = parser.parse_args()
    
    process_stream(args.n)