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Automating Tasks with Python

Python is widely used to automate repetitive tasks such as file management, scheduling, and sending emails — saving time and reducing errors.

Why Automate with Python?

Python's simple syntax and rich standard library make it ideal for automating boring, repetitive tasks: renaming files, organizing folders, sending scheduled reports, filling forms, and more.

File and Folder Automation

The os and shutil modules let you create, move, copy, rename, and delete files and directories. The pathlib module provides an object-oriented way to work with paths.

Working with Dates and Scheduling

The datetime module handles dates and times. For running tasks on a schedule, libraries like schedule or the OS-level cron/Task Scheduler are used.

Sending Emails

The built-in smtplib module can send emails via an SMTP server, useful for automated notifications and reports.

Automating Repetitive Input

Combining loops, file I/O, and conditionals lets you process hundreds of files or records automatically — for example, renaming a batch of images or generating reports from data files.

Best Practices

Always test automation scripts on sample/copy data first, log actions taken, and handle errors gracefully so a script doesn't silently delete or overwrite important files.

Syntax

<pre><code>import os
import shutil
from pathlib import Path
from datetime import datetime

# Listing files in a directory
for filename in os.listdir("."):
    print(filename)

# Creating a directory
os.makedirs("backup", exist_ok=True)

# Copying and moving files
shutil.copy("report.txt", "backup/report.txt")
shutil.move("old_name.txt", "new_name.txt")

# Using pathlib for paths
folder = Path("documents")
for file in folder.glob("*.txt"):
    print(file.name)

# Renaming files in bulk
for file in folder.glob("*.jpeg"):
    new_name = file.with_suffix(".jpg")
    file.rename(new_name)

# Working with dates
now = datetime.now()
timestamp = now.strftime("%Y-%m-%d_%H-%M-%S")
backup_name = f"backup_{timestamp}.zip"

# Sending an email (simplified)
import smtplib
from email.mime.text import MIMEText

msg = MIMEText("Automated report attached.")
msg["Subject"] = "Daily Report"
msg["From"] = "bot@example.com"
msg["To"] = "team@example.com"

# with smtplib.SMTP("smtp.example.com", 587) as server:
#     server.starttls()
#     server.login("user", "password")
#     server.send_message(msg)
</code></pre>

Revision Notes

• os and shutil for file/folder operations (copy, move, delete, rename)
• pathlib.Path provides an object-oriented file path API
• datetime for timestamps; useful in filenames and logs
• smtplib sends emails programmatically
• Always test automation on sample data before running on real files
• Combine loops + conditionals + file I/O for batch processing

Batch Rename File Extensions

Medium

Write a function new_extensions(filenames, old_ext, new_ext) that takes a list of filename strings, and for any filename ending with old_ext, returns a new list where that extension is replaced with new_ext. Filenames not matching old_ext are left unchanged.

Input:

filenames=["photo1.jpeg", "photo2.jpeg", "notes.txt"], old_ext=".jpeg", new_ext=".jpg"

Output:

['photo1.jpg', 'photo2.jpg', 'notes.txt']

Show Hint

Use str.endswith(old_ext) to check each filename, and if it matches, use slicing or replace to swap the extension. Build the result with a list comprehension.

Solve this Challenge

Show Solution

def new_extensions(filenames, old_ext, new_ext):
    result = []
    for name in filenames:
        if name.endswith(old_ext):
            base = name[: -len(old_ext)]
            result.append(base + new_ext)
        else:
            result.append(name)
    return result

print(new_extensions(["photo1.jpeg", "photo2.jpeg", "notes.txt"], ".jpeg", ".jpg"))

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