Debugging Exercise: Python Calculator

This code is designed to be used as a debugging exercise, specifically to practice using a debugger with conditional breakpoints.

Code Description

The Python code implements a simple calculator that performs basic arithmetic operations (addition, subtraction, multiplication, and division) on randomly selected numbers from two predefined lists.

Key Components:

• add(n1, n2): Returns the sum of n1 and n2.
• sub(n1, n2): Returns the difference of n1 and n2.
• mul(n1, n2): Returns the product of n1 and n2.
• div(n1, n2): Returns the quotient of n1 and n2.
• menu(): Displays a menu of options (addition, subtraction, multiplication, division, and exit) and prompts the user to enter their choice. It includes error handling to ensure the user enters a valid integer.
• Main loop:
  • Calls the menu() function to get the user's choice.
  • Uses randint to select two random numbers from C.numberListA and C.numberListB.
  • Prints the indices of the chosen numbers.
  • Performs the selected arithmetic operation using a match statement.
  • Prints the result of the operation.
  • The loop continues until the user chooses the "Exit" option.

How to Use This as a Debugging Exercise

Set up your debugging environment: Use a Python IDE (like VS Code, PyCharm, or others) or the built-in pdb debugger.

Don't modify the code ! Make it works by using debugger only !

Breakpoint condition example

Simple condition

• n2==0

Mutiple condition:

• n2==0 or not isinstance(...)

Insert breakpoints:

• Use conditional breakpoints: This is the crucial part of the exercise. Set conditions on your breakpoints to make the program pause only when specific conditions are met.

• Modify variables: Many debuggers allow you to change the values of variables while the program is paused at a breakpoint.

  Place breakpoints at key lines in the code, such as:

  • At the beginning of each of the arithmetic functions (add, sub, mul, div) with a conditional breakpoint to stop execution if n1 or n2 is not in the right type
  • Inside the while loop in the menu() function, place a log type breakpoint
  • Break only when indexN1 or indexN2 is outside the expected range (to check for potential index errors, although the provided code is unlikely to produce an index error).
  • Break in the div function only if n2 is 0. (Important: The provided code does not handle division by zero. You could add a conditional breakpoint and/or code to handle this.)
  • ...