Python script to check DNS info given a list of domains and output to text file

dns_info.py

import dns.resolver
import sys

def get_dns_info(domain):
    try:
        result = {}
        for record_type in ['A', 'AAAA', 'MX', 'NS', 'TXT', 'CNAME']:
            try:
                answers = dns.resolver.resolve(domain, record_type)
                result[record_type] = [str(rdata) for rdata in answers]
            except dns.resolver.NoAnswer:
                result[record_type] = 'No Answer'
            except dns.resolver.NXDOMAIN:
                result[record_type] = 'Domain does not exist'
                break
            except Exception as e:
                result[record_type] = f'Error: {e}'
        return result
    except Exception as e:
        return {'Error': str(e)}

def read_domains_from_file(file_path):
    try:
        with open(file_path, 'r') as file:
            domains = file.readlines()
        return [domain.strip() for domain in domains]
    except Exception as e:
        print(f"Error reading file: {e}")
        sys.exit(1)

def write_output_to_file(output, file_path):
    try:
        with open(file_path, 'w') as file:
            file.write(output)
    except Exception as e:
        print(f"Error writing to file: {e}")

def main(input_file, output_file):
    domains = read_domains_from_file(input_file)
    output = ''
    
    for domain in domains:
        dns_info = get_dns_info(domain)
        output += f"DNS Information for {domain}:\n"
        for record_type, records in dns_info.items():
            output += f"  {record_type}: {records}\n"
        output += '\n'

    print(output)
    write_output_to_file(output, output_file)

if __name__ == "__main__":
    if len(sys.argv) != 3:
        print("Usage: python script.py <input_file> <output_file>")
        sys.exit(1)

    input_file = sys.argv[1]
    output_file = sys.argv[2]
    main(input_file, output_file)