What criteria can be considered signs of well-written and correct code?

Well-written and correct code usually has the following features:

• Readability: code is easy to understand by other developers, using clear variable and function names.
• Maintainability: the structure of the code allows easy modifications and bug fixes.
• Absence of redundancy: no code duplication, repeated parts are extracted into functions or classes.
• Adherence to standards: following PEP8 for Python, consistent coding style.
• Correctness: code performs the intended task without errors and with proper logic.
• Testability: code is easy to cover with tests, functions have a small scope of responsibility.

Example of simple and readable Python code:

def calculate_area(radius):
    """Calculates the area of a circle given the radius."""
    pi = 3.14159
    return pi * radius ** 2

area = calculate_area(5)
print(f"Circle area: {area}")