Lines of Code

# lines.py

import sys
import os

def main():
    # Check for exactly one command-line argument
    if len(sys.argv) != 2:
        sys.exit("Usage: python lines.py filename.py")

    filename = sys.argv[1]

    # Check file extension
    if not filename.endswith(".py"):
        sys.exit("Not a Python file")

    # Check if file exists
    if not os.path.isfile(filename):
        sys.exit("File does not exist")

    # Count lines of code
    try:
        with open(filename, "r") as file:
            lines = file.readlines()
            count = 0
            for line in lines:
                stripped = line.strip()
                if stripped == "":
                    continue  # Blank line
                if stripped.startswith("#"):
                    continue  # Comment line
                count += 1
            print(count)
    except FileNotFoundError:
        sys.exit("File not found")

if __name__ == "__main__":
    main()