Overview
This lecture covers the fundamentals of Python programming, focusing on core syntax, data types, writing and running code, modules, comments, arithmetic operators, variables, input/output, and an introduction to object-oriented programming. It also includes practical exercises and projects to reinforce learning.
Introduction to Python and Programming
- Programming is the method to communicate instructions to a computer using languages like Python.
- Python is chosen as a first language because of its simplicity and readability.
- Programming languages help us automate tasks, process data, and build software.
Python Installation and Setup
- Download Python from the official website and install it, ensuring to add Python to PATH.
- Install and configure Visual Studio Code (VS Code) as an editor, and add the Python extension.
Writing and Running Python Programs
- Python files use the
.py extension.
- Write code in a new file, e.g.,
first.py, and run it using the terminal: python first.py.
print("Hello World") outputs text to the terminal.
Modules and pip
- A module is a file containing reusable code; it can be built-in or external.
pip is Python's package manager, used to install external modules (e.g., pip install flask).- Import modules in your program using
import modulename.
REPL and Python as a Calculator
- Start REPL in the terminal by typing
python.
- Use Python as a calculator directly in REPL for calculations like
5 + 6.
Comments in Python
- Single-line comments start with
# and are ignored by Python.
- Multi-line comments use triple quotes (
''' or """) and are also ignored.
- Use comments to explain code or temporarily disable lines.
Variables and Data Types
- Variables store data; assignment uses
=.
- Common data types: int (1), float (1.5), str ("hello"), bool (True/False), None (no value).
- Variable names must start with a letter or underscore and cannot contain spaces or special symbols.
Operators in Python
- Arithmetic:
+, -, *, /, % (modulo for remainder).
- Assignment:
=, +=, -=, etc.
- Comparison:
==, !=, >, <, >=, <=.
- Logical:
and, or, not.*
Input and Output
- Use
input() to take user input (always returns string).
- Convert input to numbers using
int() or float().
- Output results using
print().
Practice Sets & Projects
- Practice: Printing poems, tables, and working with modules.
- Create and run basic Python programs to reinforce concepts.
- Work on mini-projects like "Snake Water Gun" game and voice assistant Jarvis.
Object-Oriented Programming Basics
- Classes are blueprints for objects; objects are instances with their own data/behavior.
- Define classes using the
class keyword and create objects from them.
Key Terms & Definitions
- Variable — a named container storing data.
- String — text enclosed in quotes.
- Module — a file containing Python code, functions, or classes.
- pip — Python package installer for managing modules.
- REPL — Read-Evaluate-Print-Loop, an interactive Python shell.
- Comment — code annotation ignored during execution.
- Class — a blueprint for creating objects in OOP.
- Object — an instance created from a class.
- Function — a reusable block of code.
Action Items / Next Steps
- Complete the assigned practice problems for each chapter.
- Download the Python handbook, cheat sheets, and source code provided with the course.
- Explore hands-on mini projects and experiment with Python syntax.
- Review OOP concepts and try creating your own classes and objects.