Python Tutorial by Mosh Hamedani

Introduction

• Aimed at beginners with no prior knowledge
• Focus on data science, machine learning, web development
• Mosh Hamedani, experienced instructor

Why Learn Python?

• Multi-purpose language
• Machine Learning and AI: No. 1 language
• Web Development: Framework - Django
  • Examples: YouTube, Instagram, Spotify, Dropbox, Pinterest
• Automation: Increase productivity by automating tasks

Setting Up Python

1. Download from Python.org
2. Install Python

• Important checkbox: Add Python to PATH

3. Install a code editor (e.g., PyCharm)

• Community Edition (free & open-source)

Writing First Python Program

1. Create a new project in PyCharm
2. Write print("Hello World")
3. Explanation:

• print is a function
• "Hello World" is a string (textual data)
• Strings can use single or double quotes

4. Running the code

• Use Run menu or shortcut

Variables in Python

• Store data using variables
• Example: age = 20
• Printing variables: print(age)
• Changing values: Update variable and re-run
• Types of variables: integers, floats, strings, booleans
• Naming conventions: use underscores for readability (first_name)

Receiving Input

• input function: name = input("What is your name?")
• String concatenation: print("Hello " + name)
• Type conversion: int, float, bool, str
• Example: convert user input for age calculation

String Methods

• Strings are objects with methods
  • Examples: upper(), lower(), find(), replace()
• Immutable nature of strings
• Checking substring: in keyword

Arithmetic Operations

• Basic operators: +, -, *, /, // (integer division), % (modulus), ** (exponentiation)
• Order of operations (operator precedence)
• Augmented assignment operators: +=, -=, *=, etc.

Comparison & Logical Operators

• Comparison: >, <, >=, <=, ==, !=
• Logical: and, or, not

If Statements

• Basic syntax: if, elif, else
• Indentation for blocks
• Example: temperature check program

While Loops

• Repeat code block with condition
• Structure: initialize variable, while condition, update variable
• Example: print numbers from 1 to 5

For Loops

• Iterate over sequences (lists, ranges)
• Example: List of numbers for item in numbers

The range Function

• Generate sequence of numbers
• Syntax variations: range(5), range(5, 10), range(5, 10, 2)
• Often used in for loops

Lists

• Ordered collection of items
• Creating lists: names = ["John", "Bob", "Mosh"]
• Accessing elements: indexes (positive and negative)
• Slicing lists: names[0:3]
• List methods: append(), insert(), remove(), clear()
• Checking membership: in operator
• Getting length: len()

Tuples

• Similar to lists but immutable
• Defined using parentheses: numbers = (1, 2, 3)
• Methods: count(), index()
• Use cases: Ensuring data integrity

Additional Resources

• Comprehensive Python course available at CodeWithMosh.com
• Includes advanced topics, 30-day money-back guarantee, certificate of completion