如何根据发送命令的输出打印读取“检测到输入错误”的行？

Question

I am new to python and I am currently writing a python script that sends a command to a Cisco switch and returns specific lines. The part I am having difficulties with is how would I print a line that states "input errors detected" based on the output of the command. For example, if there 0 input errors in a line, it would do nothing but if the line has a value greater than zero input errors it would print "input errors detected"? Thanks.

The command (ssh_session.send_command("sh interfaces | in up|CRC")) returns lines like these " 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored"

for device in (cisco1, cisco2):
    ssh_session = netmiko.ConnectHandler(**device)
    print("+++++ {0} +++++".format(device["ip"]))
    output = (ssh_session.send_command("sh interfaces | in up|CRC"))
    for line in output.splitlines():
            if "input errors" in line:
                    print(line)
    ssh_session.disconnect()

Answer 1

What you need to do is parse the output message. Here's one way (there might be better ways):

• Find the occurrence of "input errors" in the output; if not found - no errors
• Get the substring of the output that precedes "input errors"
• Parse this substring as an integer
• If the parsed integer is > 0 then you can print "errors found"

This assumes the structure of the output is what you have pasted above - might have a lot of edge cases.