题解 | #整数与IP地址间的转换#

用到int和bin函数，在10进制和2进制之间反复转换

def transfer_ip2num(ip):
    ip_list = ip.split('.')
    bin_str = ''
    for x in ip_list:
        bin_str += bin(int(x))[2:].rjust(8,'0')
    return int('0b'+ bin_str, 2)

def transfer_num2ip(num):
    result = ''
    bin_str = bin(int(num))[2:].rjust(32,'0')
    for idx in range(4):
        result = result + str(int('0b' + bin_str[idx*8:idx*8+8], 2)) + '.'
    return result[:-1]

if __name__ == '__main__':
    while True:
        try:
            print(transfer_ip2num(input()))
            print(transfer_num2ip(input()))
        except EOFError: break