在Python中解析Cisco输出

Question

我试图解释开关的以下输出。基本上，我希望它遍历输出，直到找到“notconnect”，然后将接口的名称存储在数组中。然后继续遍历该文件，并将下一个“notconnect”接口存储为数组中的下一个元素。下例中的接口是Gi1/0/4。我只是不知道从哪里开始。任何帮助都将不胜感激。我使用的是python3.3.2。在

b'\r\n\r\nMS-2673-DC-CS01#terminal length 0\r\nMS-2673-DC-CS01#sh interface status\r\n\r\nPort      Name               Status       Vlan       Duplex  Speed Type\r\nGi1/0/1   Connection to MS-2 connected    trunk      a-full a-1000 1000BaseSX SFP\r\nGi1/0/2   Connection to MS-2 connected    trunk      a-full a-1000 1000BaseSX SFP\r\nGi1/0/3   Connection to MS-2 connected    trunk      a-full a-1000 1000BaseSX SFP\r\nGi1/0/4                      notconnect   trunk        auto   auto Not Present\r\nGi1/0/5   Connection to MS-2 connected    trunk      a-full a-1000 1000BaseSX SFP\r\nGi1/0/6   Connection to MS-2 connected    trunk      a-full a-1000 10/100/1000BaseTX SFP\r\nGi1/0/7   Connection to MS-2 connected    trunk      a-full a-1000 10/100/1000BaseTX SFP\r\nGi1/0/8   Connection to MS-2 connected    trunk      a-full a-1000 10/100/1000BaseTX SFP\r\nGi1/0/9   Connection to MS-2 connected    trunk      a-full a-1000 10/100/1000BaseTX SFP\r\nGi1/0/10  Connection to MS-2 connected    trunk      a-full a-1000 10/100/1000BaseTX SFP\r\nGi1/0/11  Connection to MS-2 connected    trunk      a-full a-1000 10/100/1000BaseTX SFP\r\nGi1/0/12  Connection Server  connected    32         a-full a-1000 10/100/1000BaseTX SFP\r\nMS-2673-DC-CS01#exit\r\n'

Answer 1

首先，你必须弄清楚是什么格式。然后可以编写代码来解析它。在

显然，这是一种固定宽度的列格式。接口总是在前10个字符中，连接字符串在后20个字符中，等等。因此，给定一行：

components = (line[:10], line[10:29], line[29:42], line[42:53], line[53:60],
              line[60:67], line[67:])

…将得到列。在

所以，只需循环这些行，将每行拆分成列，然后找到正确的行：

^{pr2}$

如果您想要更一般的东西，只需编写一个列拆分函数，它接受一行和一系列列边界。在

def parse_line(line, columns):
    for start, stop in zip(columns, columns[1:])
        yield line[start, stop].rstrip()

def parse_log(log):
    for line in log.splitlines():
        yield list(parse_line(line, (0, 10, 29, 42, 53, 60, 67, 80)))

def find_notconnected(log):
    for port, name, status, vlan, duplex, speed, type in parse_log(log):
        if status == 'notconnect':
            yield port

您也可以将其转换为genexpr序列，而不是一组函数。稍微简洁一点，但可能读不到：

bounds = (0, 10, 29, 42, 53, 60, 67, 80)
columns = ([line[start:stop].rstrip() for start, stop in zip(bounds, bounds[1:])]
           for line in log.splitlines())
notconnected = (port for port, _, status, _, _, _, _ in columns 
                if status == 'notconnected')