DMarlon Studio
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Python · tkinter

Calculator

The first app you make with the studio: a window with buttons drawn in the Designer and a little Python. Each button has its event and the calculation state lives in the window's class.

What it shows

  • A window designed by dragging buttons
  • One event per button and the state in the class
  • Keyboard shortcuts
macOSWindows
Calculator: Type the operation

How it works

  1. Step 1: Type the operation
    1

    Type the operation

    Press the buttons or use the keyboard. Each button calls its event (Btn7_click, BtnMul_click…) and the display shows what you type.

  2. Step 2: Get the result
    2

    Get the result

    The = button calculates with exact decimals (Python's Decimal), so 0.1 + 0.2 gives 0.3, not 0.30000000000000004.

  3. Step 3: Errors close nothing
    3

    Errors close nothing

    Dividing by zero shows “Error” on the display; the next key starts a new calculation. That is how a real app handles failures.

This demo comes as an example in DMarlon Studio: open it in the Designer to see its design and code, change it and press Run.