A quick script to accumulate the "total" column of `vnstat -5hdm` output

accumulate_vnstat_output.py

import re
from typing import List


"""
This scripts accumulates the 'total' column of vnstat output in this format:

wlan0  /  hourly

         hour        rx      |     tx      |    total    |   avg. rate
     ------------------------+-------------+-------------+---------------
     2019-12-16
         15:00      4.29 MiB |    1.88 MiB |    6.17 MiB |   14.38 kbit/s
         16:00     88.34 KiB |  202.69 KiB |  291.03 KiB |      662 bit/s
         17:00    152.35 KiB |  482.23 KiB |  634.58 KiB |    1.44 kbit/s
         18:00     40.09 KiB |  142.19 KiB |  182.27 KiB |      414 bit/s
         19:00     30.35 KiB |   82.41 KiB |  112.76 KiB |      256 bit/s
"""

file_name = 'vnstat_output.txt'
with open(file_name) as f_obj:
    lines = f_obj.readlines()  # read all the lines

res: List[float] = []
for line in lines:
    lst: List[str] = line.split('|')
    if len(lst) == 4:  # use only data row
        ma = re.search(r'(\d+\.\d+)\sKiB', lst[2])  # extract value from 'total' column
        if ma is not None:
            res.append(float(ma.group(1)))
print(res)
print(sum(res))