Decorators in Python are a metaprogramming construct: a higher-order function that accepts a function and returns a modified version of it without altering the original function's source, applied via the `@` syntax. Because decorators compose by wrapping (evaluated bottom-to-top, with each layer able to run logic both before and after invoking the wrapped callable), the order of stacked decorators determines execution sequence and can produce non-obvious interaction effects between concerns like authentication and caching. Decorators also alter the effective signature, identity metadata (`__name__`, `__doc__`), and calling contract of the wrapped function, which is why identity-preservation utilities (e.g., `functools.wraps`) and explicit type annotations exist to counteract the metaprogramming's side effects on introspection and static analysis.
Decorators in Python are a metaprogramming construct: a higher-order function that accepts a function and returns a modified version of it without altering the original function's source, applied via…