code: def get_avatar(from_header, size=64, default="retro"):
      
      params = OrderedDict([("s", size), ("d", default)])
      query = parse.urlencode(params)
      address = email.utils.parseaddr(from_header)[1]
      value_hash = sha256(address.encode("utf-8")).hexdigest()
      return "https://seccdn.libravatar.org/avatar/{}?{}".format(value_hash, query)
docs: Get the avatar URL from the email's From header.
  
      Args:
          from_header (str): The email's From header. May contain the sender's full name.
  
      Returns:
          str: The URL to that sender's avatar.