Test 3: Testing main.py output...
SUCCESS: main.py prints the correct message!
Output was: --- Self-Verification ---
Add 5 + 3 = 8
Subtract 10 - 4 = 6
Multiply 6 * 7 = 42
Divide 10 / 2 = 5.0
Divide 5 / 0 = Error: Division by zero
-------------------------
Calculator ready!
Main output test passed!