Switch from Java Developer to Python Developer

A simple 8-week plan to help Java Developers learn core Python, popular frameworks, and build a showcase app. Fit for busy professionals.

Weekly Hours: 10
Estimated Weeks: 8

Phases

Foundation: Learn Python Basics

Start learning Python syntax and data types. Practice writing and running scripts. Get comfortable with basic problem solving.

2 weeks

Write simple Python scripts
Work with lists and dictionaries
Understand functions and control flow
Set up Python on your computer

Reading Python code (print statements, loops, conditions)
Writing functions (calculate area, say hello)
Handling errors (try/except for file reading)

Python Official Tutorial
Codecademy Python Track
Automate the Boring Stuff

Complete 10 Python script exercises
Submit a code review for simple scripts

Core Skills: Object-Oriented and Essentials

Deepen Python skills with classes and modules. Learn about packages and virtual environments. Try reading and writing files.

2 weeks

Write classes and objects
Organize code in files and folders
Use third-party packages
Read and write to text files

Writing classes (Dog class with bark method)
Creating virtual environments (venv)
Importing and using packages (requests for HTTP calls)

Real Python Tutorials
W3Schools Python OOP
Official Python Documentation

Make a class-based script with two classes
Submit script that reads/writes a file

Frameworks: Web with Flask and Testing

Start using Flask to build web apps. Learn to make web routes and forms. Write tests to check your code works.

2 weeks

Build simple web routes
Handle web forms
Write tests for routes
Use templates to render HTML

Building web routes (display hello world)
Creating forms (add user form)
Writing tests (check if route returns 200)

Flask Official Docs
Test-Driven Development with Python
PyTest Basics Guide

Demo Flask app with two routes and a form
Passing tests for every route

Depth: Showcase Project Build

Move all your skills into practice. Build and refine a CRUD (Create, Read, Update, Delete) Notes app using Flask, forms, templates, and tests.

2 weeks

Design and plan the Notes app
Implement all CRUD features
Write tests for main features
Document setup and usage

Database access (sqlite for storing notes)
Deploying project (render or PythonAnywhere)
Writing user documentation (setup guide)

Flask Mega-Tutorial Chapters
PythonAnywhere Deployment Guide
Markdown Basics

Show working CRUD Notes app with tests and docs
Deploy live demo and share project link

Polish: Review, Feedback, and Next Steps

Review your showcase project, improve where needed, and seek feedback. Update your resume and profiles to highlight new skills.

1 weeks

Review and refactor your code
Ask for code feedback
Update your resume
Share the project on GitHub

Refactoring code (rename functions, add comments)
Writing README (project overview, how to run app)
GitHub basics (push code, add README)

GitHub Getting Started
Resume Python Projects Guide

Code passes review checklist
Polished README and updated resume with project

Weekly Plan

Week	Focus	Why	Tasks	Deliverables
1	Learn Python basics and set up environment	Knowing Python basics makes all next steps easier.	Install Python and code editor (VS Code), Complete Python variables and types exercises (Codecademy), Practice basic data structures (lists, dictionaries in IDLE), Write three simple scripts (greeting, calculator, file writer)	3 working Python scripts
2	Deepen skills with functions, control flow, and error handling	Functions and error handling are core for all Python jobs.	Write Python functions (sum list, format strings), Use loops and if-else statements (FizzBuzz), Add try/except blocks to handle errors, Ask for review on two scripts	Code review feedback, 2 improved scripts
3	Learn object-oriented Python and using packages	Modern Python uses classes and packages everywhere.	Write a simple class (Book with title and author), Install and use one package (requests for HTTP request), Organize scripts using folders and modules, Create and use a virtual environment (venv)	Book class script, A script using requests package
4	File I/O and class-based script practice	Reading/writing files is a common developer task.	Read data from a CSV file (csv module), Save output to a new file, Expand class script to log data to file, Submit code for peer or online review	CSV file reading script, Reviewed class-based script
5	Introduction to Flask and building web routes	Flask is a popular way to make Python web apps.	Install Flask and run demo app, Write basic routes (home, about), Create a simple HTML template (Jinja2), Write test to check route (pytest)	Demo Flask app with 2 routes, Route test script
6	Handling forms and improving Flask app with tests	Forms let users interact with web apps.	Add a form to app (add note form), Process form input and save to list, Write tests for form route, Refactor code to use templates everywhere	Flask app with add-note form, Form route test passing
7	Build and test your CRUD Notes app	A real project shows you understand end-to-end Python development.	Plan Notes app features (Create, Read, Update, Delete), Add SQLite database to store notes, Write routes for add, edit, view, and delete, Test each route (pytest)	Features list, Working CRUD Notes app
8	Polish project, deploy, and update your portfolio	Deployment and documentation show off your real skills.	Deploy Notes app online (PythonAnywhere), Write clear README (setup, usage), Push project to GitHub, Update resume and LinkedIn with project	Live demo link, Finished README and updated resume