import re


def valid_ip(string):
    """ Checks if given string is a valid IP address

    Args:
        string (str): String to check IP against

    Returns:
        bool: True if string is a dotted-quad IP address
    """
    if re.search(r"^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$", string):
        return True
    return False