🔐 Python Login Application

Academic project developed as part of the Certificate IV in Information Technology at TAFE NSW (Sydney, Australia).

A console-based login application built in Python that handles user registration, authentication and account display — storing credentials in a text file.

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📋 Project Overview

Unit assessed: ICTPRG302 – Apply Introductory Programming Techniques

The application simulates a simple login system with three components as per the client requirements from Gelos Enterprises:

• Component 1 – New user registration
• Component 2 – User login and authentication
• Component 3 – Display existing user accounts

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💡 Features

• Register a new user with username and password
• Password validation — minimum length of 10 characters
• Login authentication by comparing input against stored credentials
• Display all registered usernames (without passwords)
• Persistent data storage using a text file (accounts.txt)
• Recursive input handling for invalid entries

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📁 Files

File	Description
login_app.py	Main Python application — all three components
accounts.txt	Text file storing registered usernames and passwords

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⚙️ How It Works

--Main Menu--

Type 1 for New Registration
Type 2 for Login
Type 3 for Exit

Registration: User enters a username and password (min. 10 characters) → saved to accounts.txt as username,password

Login: User enters credentials → compared line by line with accounts.txt → displays all usernames if successful

Display Users: Lists all registered usernames and total count

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🔍 Key Concepts

# File write — append new user
myfile = open("accounts.txt", "a")
myfile.write(f"{username},{password}\n")

# File read — authenticate user
lines = myfile.read().splitlines()
for line in lines:
    words = line.split(",")
    if words[0] == username and password == words[1]:
        print("Correctly Username and Password!!")

Concepts applied:

• Functions (def)
• File I/O (open, read, write, splitlines, split)
• Input validation (len)
• Loops (for)
• Conditionals (if/elif/else)
• Recursion for invalid input handling
• String formatting (f-strings)
• sys.exit() for clean program termination

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🛠️ Technologies

• Python 3
• File I/O (text file as data store)
• Console-based UI

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▶️ How to Run

python login_app.py

Make sure accounts.txt exists in the same directory before running.

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🎓 Context

Completed as Assessment Event 2 of 3 for the unit ICTPRG302 — Certificate III in Information Technology at TAFE NSW, Sydney, Australia (2024).

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Julio Cesar da Silva Filho | LinkedIn