Python → OOP → GUI

Python is an interpreted, high-level language. It executes code line-by-line using an interpreter, making it slower but easier to debug than compiled languages.

Download from python.org. Use VS Code or PyCharm for a better coding experience with autocomplete and debugging tools.

Python uses indentation (spaces) instead of braces {} to define code blocks. Writing clean, readable code is mandatory.

The building blocks. Integers for whole numbers, floats for decimals, strings for text, and booleans for True/False logic.

Convert data types using int(), str(). Use input() to get user data and print() to show results.

Decision making. If a condition is true, do X; otherwise, check elif, or do else.

Repeat actions. for iterates over sequences (like lists), while repeats as long as a condition is true.

Lists [] are ordered & mutable. Tuples () are immutable. Sets {} represent unique items. Dictionaries {key:value} store mappings.

Use def name(): to create reusable code blocks. Lambdas are small, anonymous one-line functions.

Expand functionality with import math or import random. Python has a massive standard library.

A Class is a blueprint (e.g., Car). An Object is a specific instance (e.g., That Red Toyota). Everything in Python is an object.

__init__ is the constructor that runs when creating an object. self refers to the specific object instance being operated on.

Hiding internal details (private variables) and exposing only what's necessary to the user.

Inheritance lets a class derive fields from a parent. Polymorphism allows different classes to be treated as instances of the same general class.

The standard Python GUI library. Create a root window, add Label widgets for text and Button widgets for actions.

pack() stacks widgets. grid() uses rows/columns (best for forms). place() uses exact pixel coordinates.

The communication mechanism. A Signal (event like a click) connects to a Slot (function) to perform an action.

A drag-and-drop tool to design GUIs visually, saving them as .ui files which can be converted to Python code.

GUIs freeze if you run long tasks on the main thread; use threading to prevent this. Use PyInstaller to bundle your script into an .exe file.