代码是从某开源项目中找到的，忘了出处，侵删。

def is_ip(value):    import sys, os, socket    PY2 = sys.version_info[0] == 2        """Determine if the given string is an IP address.    Python 2 on Windows doesn't provide ``inet_pton``, so this only    checks IPv4 addresses in that environment.    :param value: value to check    :type value: str    :return: True if string is an IP address    :rtype: bool    """    if PY2 and os.name == 'nt':        try:            socket.inet_aton(value)            return True        except socket.error:            return False    for family in (socket.AF_INET, socket.AF_INET6):        try:            socket.inet_pton(family, value)        except socket.error:            pass        else:            return True    return False