What is __doc__?

__doc__ is a special attribute in Python that gets the docstring of that object. Docstrings are brief texts that explain what something does. You can access this docstring for any Python object (such as functions, classes, etc.) that supports it, and it's defined by including a string at the beginning of the definition of the object.

For example, if you define a function like this:

def add_numbers(a, b):
    """This function adds two numbers."""
    return a + b

You can then access the docstring using __doc__:

print(add_numbers.__doc__)

This will output: This function adds two numbers.

This is useful for providing quick documentation for your code, as you can include a brief explanation of what a function or class does right in its definition.