Calculator

A stateful Calculator class implemented in calculator.py which emulates handheld calculator behavior by quantizing (rounding) after each operation to the configured precision; get_total() returns the current rounded total.

Features

• Stateful running total
• Operations: add, subtract, multiply, divide, percent, percent_add, percent_substract
• Undo most recent operation with clear()
• Reset everything with clear_all()
• Show total with get_total()
• Configurable precision and max_value via constructor (precision default: 2, max_value default: 100000)

Quick usage example

from calculator import Calculator
calc = Calculator(precision=2, max_value=1000)
calc.add(1) 
calc.add(2)
calc.add(3.333)
calc.add(100)
calc.clear() # User realises they made an error
calc.add(10) # User adds correct value
print(calc.get_total())  # -> 16.33
calc.clear_all()
print(calc.get_total())  # -> 0.00

Running tests (focused)

To run only the calculator tests used during development:

pytest -q