Python Course Lecture Notes

Introduction to Python

• Instructor: Mosh
• Python is highly popular for automation, AI, and web development (Instagram, Dropbox)
• Designed for beginners; no prior experience needed
• Course includes core concepts and three Python projects

Projects Overview

1. Grocery Store Website
   • Built using Django, a popular Python framework
   • Homepage displays products and includes an admin area for stock management
2. Music Recommendation using Machine Learning
   • Predicts music preferences based on user profiles
   • Similar to YouTube's video recommendations
3. Automation Tool
   • Python program processes thousands of spreadsheets quickly

Course Structure

• Designed for all ages and experience levels
• Hands-on exercises to build confidence
• Instructor has 20 years of experience and taught over 3 million people

Setting up Python

1. Download and install Python from python.org
   • Check latest version (e.g., Python 3.7.2)
   • Important: Add Python to PATH during installation (especially for Windows)
2. Install code editor: PyCharm
   • Professional edition (paid) or Community edition (free)

Writing Your First Python Program

• Create a new project in PyCharm:
  1. Click Create New Project
  2. Set base interpreter to Python 3
  3. Create a new Python file (e.g., app.py)
• Example Code:

print("I am Mosh Hamedani")

• Run the program and observe output in terminal.

Drawing with Python

• Another example to draw shapes:

print("o ----")
print(" |  |")

Learning Python Duration

• Consistent practice (2 hours/day for 3 months) to write basic programs
• Specialization in desired area (web development, AI, etc.)
• Total time to job readiness: 9-12 months
• Expected salary for junior developers: $50-60k

Variables in Python

• Variables are fundamental:
  • Define using name = value
  • Types: integers, floats, strings, booleans
• Example:

price = 10
rating = 4.9
name = "Mosh"

User Input

• Use input() to receive user input
• Concatenate strings for dynamic messages:

name = input("What is your name?")
print(f'Hi {name}')

Data Types and Lists

• Lists are used to store multiple items:

numbers = [1, 2, 3, 4]

• Access items using index, slice syntax, and methods like append(), remove(), sort(), count(), etc.

Functions in Python

• Define functions using def keyword:

def greet_user(name):
    print(f'Hi {name}')

• Functions can return values:

def square(number):
    return number * number

Error Handling

• Use try and except blocks to handle exceptions:

try:
    # code that may cause an error
except ValueError:
    # handle the error

Classes and Objects

• Define new types using classes:

class Dog:
    def bark(self):
        print('Woof')

• Use constructor (__init__) to initialize attributes.

Inheritance in Classes

• Use inheritance to reuse code in classes:

class Animal:
    def walk(self):
        print('Walking')
class Dog(Animal):
    def bark(self):
        print('Woof')

Modules and Packages

• Organize code into modules (files) and packages (folders).
• Import modules using:

import module_name
from module_name import function_name

Built-in Modules

• Python has many built-in modules (e.g., random, math).
• Use pip to install additional packages.

Data Handling with Pandas

• Load CSV data using Pandas:

import pandas as pd
df = pd.read_csv('filename.csv')

• Use DataFrame methods to manipulate data.

Conclusion and Next Steps

• Course provides foundational skills in Python programming.
• Explore complex projects using machine learning, Django, etc.