It’s widely known that Python is perfect (among other things) for writing a one-off disposable scripts for doing dirty tasks.

Today I found myself in need of downloading a bunch of files (several hundreds) from the internet and saving them locally. I had a two columns table in google docs which I copy-pasted into a txt file (column delimiter turned into a \t symbol).

Instead of doing it manually, I chose to write a short script.

In its entirety (including parsing command line args, logging setup), the script turned out to be 32 lines long and it illustrates the following concepts:

  • handling command line args
  • setting up and using built-in logging
  • line-wise reading of the file
  • some string operations (split, trim, replace)
  • downloading stuff (using urllib package)

This is the script:

import logging
import sys
import urllib.request
from time import sleep

[download_list, target_dir] = sys.argv[1:]
logging.basicConfig(format='%(levelname)s:%(message)s', level=logging.DEBUG)"download_list: " + download_list)"target_dir: " + target_dir)

def convert_doc_name_to_file_name(doc_name: str) -> str:
    res = doc_name.strip()
    res = res.replace(' ', '_')
    return res + ".docx"

def download(link: str, target_path: str):"downloading {link} to {target_path}")
    urllib.request.urlretrieve(link, target_path)"done")

with open(download_list) as f:
    lines = list(f)

for line in lines:
    [download_link, doc_name] = line.split("\t")
    file_name = convert_doc_name_to_file_name(doc_name)
    download(download_link, target_dir + '/' + file_name)
    sleep(1)  # not to overwhelm the server too much