Python – How to find network usage programmatically in Linux

I’m trying to count the total network traffic on the wlan1 interface from python code. So far, I’ve tried ethtool, iftop, ifstat, nethogs, but most of these tools show the ncurses interface (text library interface).

I’ve tried something like this

import subprocess
nw_usage = subprocess. Popen(['ifstat', '-i', 'wlan1'])

But it doesn’t give me the network usage value.

I don’t know how to get the network usage value in a single variable from the ncurses interface. (And I feel like there would be better ways to calculate network usage).

Any help or guidance would be a great help.

Thanks

I know it’s been a few weeks since this question, but maybe this answer is still useful 🙂

You can read device statistics from /proc/net/dev. Read the bytes sent/received and calculate the difference in a time interval. Here are some simple Python scripts that I cracked together

import re
import time

# A regular expression which separates the interesting fields and saves them in named groups
regexp = r"""
  \s*                     # a interface line  starts with none, one or more whitespaces
  (? P<interface>\w+):\s+  # the name of the interface followed by a colon and spaces
  (? P<rx_bytes>\d+)\s+    # the number of received bytes and one or more whitespaces
  (? P<rx_packets>\d+)\s+  # the number of received packets and one or more whitespaces
  (? P<rx_errors>\d+)\s+   # the number of receive errors and one or more whitespaces
  (? P<rx_drop>\d+)\s+      # the number of dropped rx packets and ...
  (? P<rx_fifo>\d+)\s+      # rx fifo
  (? P<rx_frame>\d+)\s+     # rx frame
  (? P<rx_compr>\d+)\s+     # rx compressed
  (? P<rx_multicast>\d+)\s+ # rx multicast
  (? P<tx_bytes>\d+)\s+    # the number of transmitted bytes and one or more whitespaces
  (? P<tx_packets>\d+)\s+  # the number of transmitted packets and one or more whitespaces
  (? P<tx_errors>\d+)\s+   # the number of transmit errors and one or more whitespaces
  (? P<tx_drop>\d+)\s+      # the number of dropped tx packets and ...
  (? P<tx_fifo>\d+)\s+      # tx fifo
  (? P<tx_frame>\d+)\s+     # tx frame
  (? P<tx_compr>\d+)\s+     # tx compressed
  (? P<tx_multicast>\d+)\s* # tx multicast
"""

pattern = re.compile(regexp, re. VERBOSE)

def get_bytes(interface_name):
    '''returns tuple of (rx_bytes, tx_bytes) '''
    with open('/proc/net/dev', 'r') as f:
        a = f.readline()
        while(a):
            m = pattern.search(a)
            # the regexp matched
            # look for the needed interface and return the rx_bytes and tx_bytes
            if m:
                if m.group('interface') == interface_name:
                    return (m.group('rx_bytes'),m.group('tx_bytes'))
            a = f.readline()

while True:
    last_time  = time.time()
    last_bytes = get_bytes('wlan0')
    time.sleep(1)
    now_bytes = get_bytes('wlan0')
    print "rx: %s B/s, tx %s B/s" % (int(now_bytes[0]) - int(last_bytes[0]), int(now_bytes[1]) - int(last_bytes[1]))