Question

The output of /proc/net/dev on Linux looks like this:

Inter-|   Receive                                                |  Transmit
 face |bytes    packets errs drop fifo frame compressed multicast|bytes    packets errs drop fifo colls carrier compressed
    lo:18748525  129811    0    0    0     0          0         0 18748525  129811    0    0    0     0       0          0
  eth0:1699369069 226296437    0    0    0     0          0      3555 4118745424 194001149    0    0    0     0       0          0
  eth1:       0       0    0    0    0     0          0         0        0       0    0    0    0     0       0          0
  sit0:       0       0    0    0    0     0          0         0        0       0    0    0    0     0       0          0

How can I use Python to parse this output into key:value pairs for each interface? I have found this forum topic for achieving it using shell scripting and there is a Perl extension but I need to use Python.

Answer 1

this is pretty formatted input and you can easily get columns and data list by splitting each line, and then create a dict of of it.

here is a simple script without regex

lines = open("/proc/net/dev", "r").readlines()

columnLine = lines[1]
_, receiveCols , transmitCols = columnLine.split("|")
receiveCols = map(lambda a:"recv_"+a, receiveCols.split())
transmitCols = map(lambda a:"trans_"+a, transmitCols.split())

cols = receiveCols+transmitCols

faces = {}
for line in lines[2:]:
    if line.find(":") < 0: continue
    face, data = line.split(":")
    faceData = dict(zip(cols, data.split()))
    faces[face] = faceData

import pprint
pprint.pprint(faces)

it outputs

{'    lo': {'recv_bytes': '7056295',
            'recv_compressed': '0',
            'recv_drop': '0',
            'recv_errs': '0',
            'recv_fifo': '0',
            'recv_frame': '0',
            'recv_multicast': '0',
            'recv_packets': '12148',
            'trans_bytes': '7056295',
            'trans_carrier': '0',
            'trans_colls': '0',
            'trans_compressed': '0',
            'trans_drop': '0',
            'trans_errs': '0',
            'trans_fifo': '0',
            'trans_packets': '12148'},
 '  eth0': {'recv_bytes': '34084530',
            'recv_compressed': '0',
            'recv_drop': '0',
            'recv_errs': '0',
            'recv_fifo': '0',
            'recv_frame': '0',
            'recv_multicast': '0',
            'recv_packets': '30599',
            'trans_bytes': '6170441',
            'trans_carrier': '0',
            'trans_colls': '0',
            'trans_compressed': '0',
            'trans_drop': '0',
            'trans_errs': '0',
            'trans_fifo': '0',
            'trans_packets': '32377'}}