python - 类型错误 : can only concatenate list (not "int") to list

Question

我正在尝试对以下代码中列表中的某些元素做一些有用的事情:

IPS=['10.254.243.83','10.254.243.82']

def commands(cmd):
    command = Popen(cmd, shell=True, stdout=PIPE)
    command_strip = command.stdout.read().strip()
    print command_strip

def main():
    for ip in IPS:
        ping = call('ping -c 3 %s' % ip, shell=True)
        commands(ping)

if __name__ == "__main__":
    main()

然后，它返回给我: python 测试.py

PING 10.254.243.83 (10.254.243.83) 56(84) bytes of data.
64 bytes from 10.254.243.83: icmp_seq=1 ttl=61 time=2.72 ms
64 bytes from 10.254.243.83: icmp_seq=2 ttl=61 time=2.05 ms
64 bytes from 10.254.243.83: icmp_seq=3 ttl=61 time=1.88 ms

--- 10.254.243.83 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2004ms
rtt min/avg/max/mdev = 1.885/2.224/2.728/0.363 ms

Traceback (most recent call last):
  File "teste.py", line 15, in ?
    main()
  File "teste.py", line 12, in main
    commands(ping)
  File "teste.py", line 5, in commands
    command = Popen(cmd, shell=True, stdout=PIPE)
  File "/usr/lib/python2.4/subprocess.py", line 543, in __init__
    errread, errwrite)
  File "/usr/lib/python2.4/subprocess.py", line 891, in _execute_child
    args = ["/bin/sh", "-c"] + args
TypeError: can only concatenate list (not "int") to list

Can someone help me with this error ?

Answer 1

你传递的返回值

call('ping -c 3 %s' % ip, shell=True)

作为您的commands() 函数的cmd 参数。提到的返回值是一个整数，作为命令没有任何意义，因此尝试使用 Popen() 执行此整数会按预期失败。