python--字符串转数字

今天遇到需要把字符串转为数字的情况，但是没有先判断字符串中是否有数字之外的，然后直接调用int()

然后运行就提示错误了

def slot_port_num(line):
    strlist  = line.split('\n')
    total_port_num = 0
    for singleline in strlist:
        slot_port_num = int(singleline)
        total_port_num = total_port_num + slot_port_num

    print("total port number:", total_port_num)
    return total_port_num

在调用int(singleline)之前，要先调用isdigit()判断singleline是否为全数字，修订之后如下

def slot_port_num(line):
    strlist  = line.split('\n')
    total_port_num = 0
    for singleline in strlist:
        if (singleline.isdigit()):
            slot_port_num = int(singleline)
            total_port_num = total_port_num + slot_port_num

    print("total port number:", total_port_num)
    return total_port_num