Python - Linux: Parse Network Stats From ifconfig

I needed to get some Linux networking stats in my Python program today. Specifically, I needed 'bytes sent' and 'bytes received' counts since last reboot from the local machine.

ifconfig is a network configuration utility for Linux that you run from the command line:

corey@studio17:~$ ifconfig eth0
eth0      Link encap:Ethernet  HWaddr 00:22:19:e5:07:31  
          inet addr:10.0.0.5  Bcast:10.0.0.255  Mask:255.255.255.0
          inet6 addr: fe80::222:19ff:fee5:731/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:3353822 errors:0 dropped:0 overruns:0 frame:0
          TX packets:3052408 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:3476310326 (3.4 GB)  TX bytes:256706611 (256.7 MB)
          Interrupt:17 

The following function parses output from ifconfig to get the network stats I was after:

import re
import subprocess

def get_network_bytes(interface):
    output = subprocess.Popen(['ifconfig', interface], stdout=subprocess.PIPE).communicate()[0]
    rx_bytes = re.findall('RX bytes:([0-9]*) ', output)[0]
    tx_bytes = re.findall('TX bytes:([0-9]*) ', output)[0]
    return (rx_bytes, tx_bytes)

Example usage:

import re
import subprocess

def main():
    rx_bytes, tx_bytes = get_network_bytes('eth0')
    print '%s bytes received' % rx_bytes
    print '%s bytes sent' % tx_bytes
      
def get_network_bytes(interface):
    output = subprocess.Popen(['ifconfig', interface], stdout=subprocess.PIPE).communicate()[0]
    rx_bytes = re.findall('RX bytes:([0-9]*) ', output)[0]
    tx_bytes = re.findall('TX bytes:([0-9]*) ', output)[0]
    return (rx_bytes, tx_bytes)

if __name__ == '__main__':
    main()

Update: someone left an anonymous comment and mentioned you can just read from proc/net/dev rather than using ifconfig. I modified his code sample and came up with this:

def get_network_bytes(interface):
    for line in open('/proc/net/dev', 'r'):
        if interface in line:
            data = line.split('%s:' % interface)[1].split()
            rx_bytes, tx_bytes = (data[0], data[8])
            return (rx_bytes, tx_bytes)

Example Usage:

def main():
    rx_bytes, tx_bytes = get_network_bytes('eth0')
    print '%s bytes received' % rx_bytes
    print '%s bytes sent' % tx_bytes
      
def get_network_bytes(interface):
    for line in open('/proc/net/dev', 'r'):
        if interface in line:
            data = line.split('%s:' % interface)[1].split()
            rx_bytes, tx_bytes = (data[0], data[8])
            return (rx_bytes, tx_bytes)

if __name__ == '__main__':
    main()