Building a Persistent Smart Contact Book CLI App Using Pure Python

Nivedya AV — Sun, 20 Sep 2026 06:25:16 +0000

Hello DEV Community!

As a 2nd-year BCA student aspiring to become a Web / Developer Advocate, I believe that mastering data structures, error handling, and file persistence is crucial. Today, I am excited to share my 4th python project: a Smart Contact Book CLI Application built completely from scratch!

Unlike basic scripts that lose data when closed, this tool stores all data locally and validates inputs efficiently to mimic real-world system behavior.

Key Features

Local Data Persistence (JSON): Stores contacts securely in a contacts.json file so data is never lost.
Robust Input Validation: Ensures phone numbers are exactly 10 digits and validates email structures (@' and.`).
Full CRUD Operations: Allows to Add, View, Search, and Delete contacts through a continuous interactive menu.
Crash-Proof Design: Uses try-except blocks to handle empty inputs or missing files gracefully.

What I Learned From This Project

Building this application helped me master several critical backend concepts:

File I/O & JSON Parsing: Reading and writing structured dictionary data using Python's inbuilt json module.
Defensive Programming: Anticipating bad user inputs and catching errors before they cause system crashes.
Git Workflow Management: Staging, committing, and managing repository files efficiently within VS code.

Source Code & Repository

I have hosted the complete codebase along with my updated learning journey on GitHub. check it out here:

Link to my GitHub Repository

I Would Iove to get your feedback on how I can optimize this logic further! Should I add an Edit/Update" feature next, or migrate the data handling into a SQLite database? Let me know in the comments!

Building an Advanced URL Shortener & ASCII QR Code Generator From Scratch Using Pure Python

Nivedya AV — Mon, 14 Sep 2026 13:42:18 +0000

Hello DEV Community!

I am a BCA Student, currently learning and building in public to pursue my dream of becoming a Web Advocate. Today, I want to share my latest project: an Advanced URL Shortener & ASCII QR Code Generator built completely from scratch!

Building this tool with zero external dependencies required careful algorithmic thinking. Here is how i structured the logic into 116 lines of clean Python code:

The Logic Breakdown & Core Features

** Smarter URL Validation: **
Before processing any link, the program implements custom validation logic to check if the user input starts with http://. If it doesn't, the tool prompts the user with a helpful error message to prevent dead or unsafe links.
** Custom URL Shortening: **The script simulates backend link mapping by creating short, unique paths for long URLs.
** ASCII QR Code Array Logic: **instead of installing a massive image library, I created a grid matrix mechanism to dynamically print a scannable ASCII QR code using block characters directly inside the terminal window.
** Positioning Corner Markers: **implemented an add_marker() helper function that precisely places 7x7 finder patterns at the three corners of the grid matrix.

key Takeaways

This project gave me a deeper understanding of input validation, array manipulations, and character-mapping for console UIs.

Check out the full repository here:
https://github.com/nivedya2008/my-python-project