What are the main principles to follow when writing quality code?

Principles of writing quality Python code:

• Readability and clarity — code should be understandable by other developers. Use clear variable and function names.

• Adherence to PEP 8 — follow the official Python coding style for consistency.

• Modularity — break code into small functions and modules, each performing a single task.

• Documentation — add docstrings to functions and classes to explain their purpose.

• Exception handling — use try/except properly to manage errors.

• Testability — write tests to verify functionality.

• Avoid code duplication — apply the DRY principle (Don't Repeat Yourself).

• Use Python's built-in features — such as list comprehensions, generators, context managers.

Example of a simple function with a docstring and exception handling:

def divide(a, b):
    """Returns the result of dividing a by b."""
    try:
        return a / b
    except ZeroDivisionError:
        print("Error: division by zero.")
        return None

This approach makes the code reliable, understandable, and easy to maintain.