What is a docstring used for and what is it?

Docstring (documentation string) in Python is a multiline string literal used to document modules, classes, functions, and methods.

Purpose of docstring:

• Code documentation: Provides a description of what a particular block of code is for, its parameters, return value, and possible exceptions.
• Documentation generation: Automated tools (e.g., Sphinx) can extract docstrings and generate readable documentation in various formats (HTML, PDF).
• Interactive help: Development tools (IDEs, Jupyter notebooks) use docstrings to provide pop-up hints and information about functions/methods.
• Debugging and testing: Helps understand code behavior without needing to read its implementation.

The docstring is written as the first statement in a module, class, function, or method.

# Example of a docstring for a function
def my_function(arg1: int, arg2: str) -> bool:
    """
    This function does something useful.

    Args:
        arg1 (int): The first integer argument.
        arg2 (str): The second string argument.

    Returns:
        bool: Returns True if the operation is successful, otherwise False.

    Raises:
        ValueError: If arg1 is a negative number.
    """
    if arg1 < 0:
        raise ValueError("arg1 cannot be negative.")
    # Function logic
    return True

# Example of accessing the docstring
print(my_function.__doc__)