Python Tutorial

Introduction

• Instructor: Mosh Hamedani
• Goal: Learn to start programming in Python
• No prior knowledge required
• Purpose: Useful for data science, machine learning, web development, automation
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Python Applications

• Multi-purpose language:
  • Machine Learning & AI: No. 1 language for these projects
  • Web Development: Framework example: Django
  • Automation: Save time, increase productivity
• Example Websites Using Python/Django:
  • YouTube, Instagram, Spotify, Dropbox, Pinterest

Getting Started

1. Download Python: Go to python.org -> Downloads -> Latest Version

   • Installation: Check "Add Python to PATH" on Windows

2. Install Code Editor: PyCharm (jetbrains.com/pycharm)

   • Choose Community Edition (Free)
   • Installation process differs slightly between Windows and Mac

Writing Your First Python Program

1. Create a New Project: Hello, World!
2. Write Code:

   print("Hello World")
   

   • print: Function to output text
   • String: Textual data within quotes

Variables

• Usage: Store data in memory for later use
• Declaration:

  age = 20 
  print(age)
  

  • Variables can store numbers, strings, and booleans
  • Case-sensitive: False vs false

User Input

• Get input from user:

  name = input("What is your name?")
  print("Hello " + name)
  

  • Use input() function to read terminal input
  • String concatenation with +

Type Conversion

• Convert string input to integers, floats, or booleans using int(), float(), bool(), and str()

  year = int(input("Birth year?"))
  age = 2020 - year
  print(age)
  

String Methods

• Common methods:
  • .upper(), .lower(), .find(), .replace(), in operator

Arithmetic Operations

• Operators: +, -, *, /, //, %, **
  • Modulus %: Returns remainder
  • Exponent **: Power calculation
• Augmented assignment:
  • +=, -=, *=, /=, //=, %=, **=

Comparison & Logical Operators

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

If Statements

• Syntax: Conditional logic for decision-making

  if temperature > 30:
      print("It's a hot day")
  elif temperature > 20:
      print("It's a nice day")
  else:
      print("It's cold")
  

Loops

• While Loops: Repeat block of code while condition is true

  i = 1
  while i <= 5:
      print(i)
      i += 1
  

• For Loops: Iterate over a sequence (list, range, etc.)

  for number in range(5):
      print(number)
  

Working with Lists

• List Creation and Access:

  names = ["John", "Bob", "Marsh"]
  print(names[0])  # Access first element
  ``
  

• List Methods: .append(), .insert(), .remove(), .clear()
• Slicing: names[0:2]
• Iterating: for item in names

Tuples

• Immutable Lists:

  numbers = (1, 2, 3)
  

• Accessing Elements: numbers[0]
• Methods: .index(), .count()

Resources

• Advanced Learning: Comprehensive Python courses at codewithmosh.com
• Online School: Courses on web/mobile development with certifications