Let's measure internet speed with Python and learn some cron basics

One evening I had poor internet and I decided to remind how to run periodic tasks on Python. First let's make a small script that will measure download and upload speed and save this data to csv file. With a little help of generative AI I had this script.

import logging
import os
import pandas as pd

from config import CSV_FILENAME, LOG_FILENAME, STORE_PATH

from speedtest import Speedtest


def _add_log() -> None:
    log = logging.getLogger(__name__)
    log.setLevel(logging.INFO)
    if not os.path.exists(STORE_PATH):
        os.makedirs(STORE_PATH)

    file_handler = logging.FileHandler(LOG_FILENAME)
    stream_handler = logging.StreamHandler()

    file_handler.setLevel(logging.WARNING)
    stream_handler.setLevel(logging.INFO)

    logging_format = logging.Formatter(
        '%(asctime)s - %(levelname)s - %(message)s')
    file_handler.setFormatter(logging_format)
    stream_handler.setFormatter(logging_format)
    log.addHandler(file_handler)
    log.addHandler(stream_handler)


def humansize(nbytes: int) -> str:
    suffixes = ['b', 'Kb', 'Mb', 'Gb', 'Tb', 'Pb']
    i = 0
    while nbytes >= 1024 and i <= len(suffixes)-1:
        nbytes /= 1024
        i += 1
    return f"{nbytes:.2f}{suffixes[i]}ps"


def main() -> None:
    log = logging.getLogger(__name__)
    log.info('Start measure')
    st = Speedtest()

    ds = humansize(st.download())
    us = humansize(st.upload())
    recorded_time = pd.Timestamp.now()

    if not os.path.exists(CSV_FILENAME):
        log.warn(
            f"File '{CSV_FILENAME}' not found. Creating a new CSV file.")
        columns = ["Datetime", "Download", "Upload"]
        df = pd.DataFrame(columns=columns)
    else:
        df = pd.read_csv(CSV_FILENAME, parse_dates=True)

    new_data = {"Datetime": recorded_time, "Download": ds, "Upload": us}

    df.loc[recorded_time] = new_data

    df.to_csv(CSV_FILENAME, index=False)
    log.info('Done')
    log.info(f"{new_data}")


if __name__ == "__main__":
    log = logging.getLogger(__name__)
    _add_log()
    try:
        main()
    except Exception as e:
        log.error(e)

Lets look it closely. This is a helper function to store errors in file due to our process will be running in crontab we will not see output of our script.

def _add_log() -> None:
    log = logging.getLogger(__name__)
    log.setLevel(logging.INFO)
    if not os.path.exists(STORE_PATH):
        os.makedirs(STORE_PATH)

    file_handler = logging.FileHandler(LOG_FILENAME)
    stream_handler = logging.StreamHandler()

    file_handler.setLevel(logging.WARNING)
    stream_handler.setLevel(logging.INFO)

    logging_format = logging.Formatter(
        '%(asctime)s - %(levelname)s - %(message)s')
    file_handler.setFormatter(logging_format)
    stream_handler.setFormatter(logging_format)
    log.addHandler(file_handler)
    log.addHandler(stream_handler)

Next one is humanize of number. Like 1024 will be 1.00kbps

def humansize(nbytes: int) -> str:
    suffixes = ['b', 'Kb', 'Mb', 'Gb', 'Tb', 'Pb']
    i = 0
    while nbytes >= 1024 and i <= len(suffixes)-1:
        nbytes /= 1024
        i += 1
    return f"{nbytes:.2f}{suffixes[i]}ps"

And here we measure download and upload speed. Using pandas read file and add new line of our result with datetime. I install lib calles speedtest-cli to measure internet speed.

def main() -> None:
    log = logging.getLogger(__name__)
    log.info('Start measure')
    st = Speedtest()

    ds = humansize(st.download())
    us = humansize(st.upload())
    recorded_time = pd.Timestamp.now()

    if not os.path.exists(CSV_FILENAME):
        log.warn(
            f"File '{CSV_FILENAME}' not found. Creating a new CSV file.")
        columns = ["Datetime", "Download", "Upload"]
        df = pd.DataFrame(columns=columns)
    else:
        df = pd.read_csv(CSV_FILENAME, parse_dates=True)

    new_data = {"Datetime": recorded_time, "Download": ds, "Upload": us}

    df.loc[recorded_time] = new_data

    df.to_csv(CSV_FILENAME, index=False)
    log.info('Done')
    log.info(f"{new_data}")

Almost all. You should create config.py where you will describe path for logs and .csv file. And now lets create periodic job using cron.

crontab -e

This will open editon for your cron jobs. Add a new line using cron syntacs

* * * * * <venv/bin/python> <path>/main.py

And that is it, easy

For more please visit Cron Doc

Python Cron Task (Measure Internet Speed)

Let's measure internet speed with Python and learn some cron basics