input: Write a function to parse the given URL and print out the protocol, domain name, and path using Python.
  
  import urllib.parse
  
  def parse_url(url):
      parsed_url = urllib.parse.urlparse(url)
      
      protocol = parsed_url.scheme
      domain_name = parsed_url.netloc
      path = parsed_url.path
      
      print('Protocol:', protocol)
      print('Domain name:', domain_name)
      print('Path:', path)
  
  parse_url('https://www.example.com/path/to/file')
  
  
  assert parse_url('https://www.example.com/path/to/file') == ('Protocol: https', 'Domain name: www.example.com', 'Path: /path/to/file')
  assert parse_url('http://another.example.net/index.html') == ('Protocol: http', 'Domain name: another.example.net', 'Path: /index.html')
  assert parse_url('ftp://files.example.org/dir/data') == ('Protocol: ftp', 'Domain name: files.example.org', 'Path: /dir/data')
  assert parse_url('https://sub.domain.com/sub/dir') == ('Protocol: https', 'Domain name: sub.domain.com', 'Path: /sub/dir')
  
output: import urllib.parse
  
  def parse_url(url):
      parsed_url = urllib.parse.urlparse(url)
      
      protocol = parsed_url.scheme
      domain_name = parsed_url.netloc
      path = parsed_url.path
      
      print('Protocol:', protocol)
      print('Domain name:', domain_name)
      print('Path:', path)