Code Reviewer

Code Review for MessyCalc General Overview The code provides a simple calculator app named MessyCalc that supports basic operations such as addition, subtraction, multiplication, and division. The code is functional but has several areas for improvement, including readability, adherence to coding standards, and input validation. Strengths Simplicity: The code is simple and straightforward, which makes it easier to understand. Function Decomposition: The arithmetic operations are separated into their own functions, making the code more modular. User Interaction: The code prompts the user for input, providing an interactive experience. Areas for Improvement Readability and Formatting 1. Single-line Functions: The arithmetic functions are defined in a single line, which, although syntactically correct, makes the code less readable. Consider expanding them into multiple lines. def add(x, y): return x + y 2. Spacing and Indentation: The code is mostly well-indented, but it could benefit from additional spacing between sections for readability. Adherence to PEP 8 Docstrings: The code lacks docstrings, which are essential for explaining the functionality of the code. Add docstrings to each function. Logic and Functionality 1. Division by Zero: The code accounts for division by zero, which is good. However, the logic for handling it is embedded within the main if-elif-else structure. Consider moving it to the divide function for better encapsulation. 2. Invalid Input: The code somewhat handles invalid choices for operations but doesn't provide the user an opportunity to re-enter their choice. 3. Type Casting: The code casts user input to floats without any error handling. If the user enters invalid data, the code will crash. Suggested Changes Here's how you can improve each area: 1. Readability: Separate the logic into different blocks, add comments, and use multiple lines for function definitions. # Function to add two numbers def add(x, y): return x + y 2. Move Division by Zero Check: Move the division by zero logic to the divide function. def divide(x, y): if y == 0: return "Cannot divide by zero!" else: return x / y 3. Add Error Handling for Inputs: Use try-except blocks for casting input to floats. try: num1 = float(input("Enter first number: ")) num2 = float(input("Enter second number: ")) except ValueError: print("Invalid number entered!") exit(1) 4. Loop for Continuous Operation: You might want to allow users to perform more than one calculation. Use a while loop to keep the application running until the user chooses to exit. Here's a revised version incorporating these suggestions: def add(x, y): """Adds two numbers.""" return x + y def subtract(x, y): """Subtracts two numbers.""" return x - y def multiply(x, y): """Multiplies two numbers.""" return x * y def divide(x, y): """Divides two numbers.""" if y == 0: return "Cannot divide by zero!" return x / y while True: print("\nWelcome to BetterCalc - the better calculator app!") print("Select operation:") print("1. Add") print("2. Subtract") print("3. Multiply") print("4. Divide") print("5. Exit") choice = input("Enter choice (1/2/3/4/5): ") if choice == '5': break try: num1 = float(input("Enter first number: ")) num2 = float(input("Enter second number: ")) except ValueError: print("Invalid number entered!") continue if choice == '1': print(f"{num1} + {num2} = {add(num1, num2)}") elif choice == '2': print(f"{num1} - {num2} = {subtract(num1, num2)}") elif choice == '3': print(f"{num1} * {num2} = {multiply(num1, num2)}") elif choice == '4': result = divide(num1, num2) print(f"{num1} / {num2} = {result}" if result != "Cannot divide by zero!" else result) else: print("Invalid choice") cont = input("Would you like to continue? (yes/no): ") if cont.lower() != 'yes': break print("Thank you for using BetterCalc!") With these changes, the code will be more readable, maintainable, and user-friendly.