Python Programming Course Notes

Introduction to Python

• Python is a popular and beginner-friendly programming language.
• Great for job seekers, automation, and writing scripts.
• Python has a simple syntax with a gentle learning curve.

Installing Python

Steps to Install Python:

1. Go to python.org/downloads.
2. Download the latest version (preferably Python 3).
3. Install Python on your computer.

Versions of Python:

• Python 2: Legacy version, not actively maintained.
• Python 3: Current version, actively maintained, recommended for beginners.

Setting Up Text Editor

• You can write Python in any text editor, but it's better to use an IDE (Integrated Development Environment).
• Recommended IDE: PyCharm.
  • Download the community version (free).

Writing Your First Python Program

Hello World Program:

• Create a new Python file in PyCharm.
• Write the code:

  print("Hello, World!")
  

• Run the program to see the output.

Basic Programming Concepts

Variables

• Variables are containers for storing data values.
• Data types include strings, integers, and booleans.

Control Structures

If Statements

• Used for decision-making in code.
• Structure:

  if condition:
      # code to execute if condition is true
  else:
      # code to execute if condition is false
  

Loops

For Loops

• Used to iterate over a sequence (like a list or a string).
• Structure:

  for item in sequence:
      # code to execute for each item
  

While Loops

• Continue to execute a block of code as long as a condition is true.
• Structure:

  while condition:
      # code to execute while condition is true
  

Functions

• Functions are blocks of reusable code that perform a specific task.
• Defined using def keyword followed by the function name and parameters.
• Can return values using the return statement.

Data Structures

Lists

• Ordered collection of items.
• Example: my_list = [1, 2, 3, 4]

Dictionaries

• Unordered collection of key-value pairs.
• Example:

  my_dict = {'key1': 'value1', 'key2': 'value2'}
  

Error Handling

Try and Except Blocks

• Used to handle exceptions and errors gracefully.
• Structure:

  try:
      # code that may raise an exception
  except ExceptionType:
      # code to handle the exception
  

File Input/Output

Reading from Files

• Use open() to read a file.
• Modes: r (read), w (write), a (append).

Writing to Files

• Use write() or writelines() to add content to a file.

Object-Oriented Programming

Classes and Objects

• Classes are blueprints for creating objects.
• Objects are instances of classes.
• Can define attributes and methods within classes.

Inheritance

• Allows one class to inherit attributes and methods from another class.
• Promotes code reusability.

Modules

• A module is a Python file containing functions, classes, or variables that can be imported into other Python files.
• Use import statement to include a module in your code.

Summary

• Python is a versatile programming language great for beginners.
• Key concepts include variables, control structures, functions, data structures, error handling, file I/O, object-oriented programming, and modules.
• Encouraged to explore external modules and third-party packages to extend functionality.