# ip ==> 數字>>> ip2num = lambda x:sum([256**j*int(i) for j,i in enumerate(x.split('.')[::-1])])>>> ip2num('192.168.0.1')3232235521

# 數字 ==> ip # 數字范圍[0, 255^4]>>> num2ip = lambda x: '.'.join([str(x/(256**i)%256) for i in range(3,-1,-1)])>>> num2ip(3232235521)'192.168.0.1'