Control structures allow you to dictate the flow of your program. They enable your code to make decisions, repeat tasks, and manage complex logic. Mastering these constructs is essential for building dynamic and efficient Python applications.

1. Conditional Statements

Conditional statements let your program choose different paths based on boolean expressions (True/False).

1.1 The if Statement

• Concept:

  Evaluates a condition; if the condition is True, the indented block below it executes.

• Syntax:

  if condition:
      # code block executed when condition is True
  
  

• Example:

  temperature = 30
  if temperature > 25:
      print("It's a hot day!")
  
  

1.2 The if-else Statement

• Concept:

  Provides an alternative block of code if the condition is False.

• Syntax:

  if condition:
      # code block if condition is True
  else:
      # code block if condition is False
  
  

• Example:

  temperature = 20
  if temperature > 25:
      print("It's a hot day!")
  else:
      print("It's not that hot.")
  
  

1.3 The if-elif-else Ladder

• Concept:

  Checks multiple conditions in order. Only the first true condition's block is executed.

• Syntax:

  if condition1:
      # code block for condition1
  elif condition2:
      # code block for condition2
  else:
      # code block if none of the above conditions are True
  
  

• Example:

  score = 85
  if score >= 90:
      print("Grade: A")
  elif score >= 80:
      print("Grade: B")
  elif score >= 70:
      print("Grade: C")
  else:
      print("Grade: D or below")
  
  

2. Looping Constructs

Loops are used to repeat code execution. Python provides several types of loops that you can use depending on your needs.

2.1 The while Loop