Python Calculator with PySide6

A modern calculator application built with Python and PySide6, featuring a unique "calculator tape" experience where expressions build up visually until you press equals. The interface enforces a consistent light theme and provides full keyboard support with persistent calculation history.

Features

• Expression Building: See your complete calculation as you type (e.g., 12 + 7 - 3) before getting the result
• Calculator Tape Experience: Screen only clears when you press equals, mimicking traditional desktop calculators
• Basic Arithmetic: Addition (+), subtraction (-), multiplication (×), division (÷) with proper operator chaining
• Full Keyboard Support: All calculator functions mapped to intuitive keyboard shortcuts
• Persistent History: Calculation history with timestamps, automatically saved between sessions
• Forced Light Theme: Consistent light interface regardless of system dark mode settings
• Error Handling: Graceful handling of division by zero and invalid expressions
• Cross-Platform: Works seamlessly on Windows, macOS, and Linux

Installation & Setup

Prerequisites

• Python 3.7 or higher
• pip (Python package installer)

Installation Steps

1. Navigate to the project directory:

cd python_calculator

2. Install required dependencies:

pip install -r requirements.txt

3. Launch the calculator:

python main.py

User Interface

Calculator Behavior

• Number Input: Numbers accumulate in the display as you type
• Operator Input: Operators are added to the expression (e.g., 12 + then 7 shows 12 + 7)
• Expression Building: Complete expressions build up visually: 12 + 7 - 3 × 2
• Equals Function: Only when you press = does the screen clear to show just the result
• History Panel: Shows your last 10 calculations with timestamps

Keyboard Shortcuts

• Numbers: 0-9 keys for digit input
• Basic Operations:
  • + for addition
  • - for subtraction
  • * for multiplication (displays as ×)
  • / for division (displays as ÷)
• Special Functions:
  • . (period) for decimal point
  • Enter or Return to calculate (equals)
  • Escape to clear all
  • Backspace to delete last character
• Additional: All buttons are also clickable with mouse

Project Structure

python_calculator/
├── main.py                 # Application entry point and launch script
├── calculator_ui.py        # User interface components and event handling
├── calculator_logic.py     # Core mathematical operations and validation
├── history_manager.py      # Calculation history persistence and management  
├── styles.py              # PySide6 stylesheet definitions for light theme
├── requirements.txt       # Python package dependencies
├── README.md             # Project documentation (this file)
├── .gitignore           # Git version control ignore rules
├── assets/              # Directory for images or additional resources
├── tests/               # Directory for unit tests (if implemented)
└── history.json         # User calculation history (auto-generated)

Architecture & Development

Code Organization

• Modular Design: Clear separation between UI, calculation logic, and data persistence
• Event-Driven: Uses PySide6's signal-slot system for responsive user interactions
• Theme Management: Centralized styling system ensures consistent appearance across all components
• Data Persistence: History automatically saves to JSON file with error handling

Key Implementation Details

• Expression Building Logic: Numbers and operators accumulate in display until equals is pressed
• Smart Input Handling: Proper spacing and validation for complex expressions
• Operator Conversion: Internal operators (* /) convert to display symbols (× ÷) for user clarity
• History Limitation: Keeps last 100 calculations to prevent excessive memory usage

Extending the Calculator

Adding New Features

• UI Modifications: Edit calculator_ui.py for interface changes
• Mathematical Functions: Extend calculator_logic.py for new operations
• Styling Updates: Modify styles.py for appearance customization
• History Features: Enhance history_manager.py for advanced history functions

Testing Recommendations

Test edge cases including:

• Division by zero scenarios
• Very large number calculations
• Complex chained operations
• Decimal precision handling
• Invalid expression inputs

Troubleshooting

Common Issues

• Import Errors: Ensure PySide6 is properly installed with pip install PySide6
• Display Issues: Restart application if light theme doesn't apply correctly
• History Problems: Check file permissions in project directory for history.json access
• Keyboard Shortcuts: Ensure calculator window has focus for keyboard input

Platform Notes

• Windows: May require Visual C++ redistributables for PySide6
• macOS: Compatible with both Intel and Apple Silicon processors
• Linux: Requires Qt6 development libraries installed

License

This project is open source and available under the MIT License.

Experience the classic calculator tape feel with modern Python technology! 🧮