Question

I’m trying to do something usefull with some itens in list in the following code:

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()

Then, it returns me:
python teste.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

You pass the return value of

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

as cmd argument to your commands() function. The mentioned return value is an integer, which does not make any sense as a command, so trying to execute this integer using Popen() fails as expected.