Beginner's Guide to Python Programming

Aug 5, 2024

Python Programming Tutorial Notes

Introduction

  • Learn everything needed to start programming in Python.
  • Suitable for data science, machine learning, and web development.
  • No prior knowledge required.
  • Instructor: Mosh Hamadani.

Applications of Python

  • Multi-purpose language: Can be used for various tasks.
  • Machine Learning & AI: Most popular language for ML and data science.
  • Web Development: Used with Django framework to build websites (e.g., YouTube, Instagram).
  • Automation: Helps save time by automating repetitive tasks.

Setting Up Python

  1. Download Python: Visit python.org, go to downloads, and get the latest version.
    • For Windows, check "Add Python to PATH" during installation.
  2. Install a Code Editor: Recommended: PyCharm.
    • Download the Community Edition (free).
    • Follow installation steps (drag to Applications for Mac).
  3. Create a New Project: Open PyCharm, skip configuring settings, create a project.
    • Name it hello_world.

Writing Your First Python Code

  1. Create a new Python file (e.g., app.py).
  2. Write a simple program: 
    print("Hello, World!")
  3. Run the code to see the output in the terminal.

Variables

  • Definition: Store data temporarily in memory.
  • Declaration:
    • Example: age = 20
    • Use variables without quotes to reference them.
  • Changing Values: e.g., age = 30
  • Types of Values:
    • Integers, floating-point numbers, strings, booleans.
  • Naming Conventions: Use underscores for multi-word variables.

User Input

  • Getting Input: Use input() function.
    • Example:
    name = input("What is your name? ")
print("Hello, " + name)

Data Types in Python

  • Primitive Types:
    • Numbers (integers and floats), Booleans, Strings.
  • Type Conversion:
    • Functions: int(), float(), str(), bool().

Example Exercise

  • Create a program for a hospital to check in a patient using variables.

Arithmetic Operations

  • Operators: +, -, *, /, //, %, and ** (exponentiation).
  • Augmented Assignment: e.g., x += 3.
  • Operator Precedence: Multiplication and division before addition.

Comparison Operators

  • Used to compare values: >, >=, <, <=, ==, !=.
  • Boolean Expression: Results in True or False.

Logical Operators

  • Used for complex conditions: and, or, not.

Control Structures: If Statements

  • If Statements: Make decisions based on conditions.
if temperature > 30:
    print("It's a hot day")
  • Use elif for additional conditions and else for fallback.

Looping: While Loops

  • While Loops: Repeat a block of code while a condition is true.
while i <= 5:
    print(i)
    i += 1

Lists

  • Definition: Ordered collection of items.
  • Creating a List: names = ["John", "Bob", "Mary"]
  • Accessing Elements: Use index notation (0-based).
  • List Methods: append(), insert(), remove(), clear(), in operator to check existence.
  • Length of List: Use len() function.

For Loops

  • Definition: Iterate over items in a collection.
for item in names:
    print(item)

Range Function

  • Generates a sequence of numbers: range(start, stop, step).

Tuples

  • Definition: Similar to lists but immutable.
  • Creating a Tuple: numbers = (1, 2, 3).
  • Methods: count(), index().

Conclusion

  • Further Learning: Consider enrolling in comprehensive courses for deeper understanding.