What are warnings used for in Python and how can you create your own warning?

Warnings are used to notify developers or users about potential problems or discouraged code usage that are not errors and do not interrupt program execution. They are less critical than exceptions.

To create a custom warning, define a new class inheriting from the built-in Warning class or its subclasses (e.g., UserWarning, DeprecationWarning).

class MyCustomWarning(UserWarning):
    # Custom warning class
    pass

To generate a warning, use the warnings.warn() function.

import warnings

def my_function(arg):
    if arg < 0:
        # Generate a custom warning
        warnings.warn("Argument should be non-negative.", MyCustomWarning)
    # Rest of the function logic
    pass

# Example of calling a function that generates a warning
my_function(-5)