Defines a function named foo that is modified by two decorators before execution.

Indicates that the function's behavior is altered or extended by the decorators before it is called.

When you need to add cross-cutting concerns such as logging, timing, access control, or memoization to a function without changing its core logic.

Python codebases that use frameworks or libraries relying on decorators (e.g., Flask, Django, pytest, functools).

@dec1 @dec2 def <function_name>([params]):

@dec1 @dec2 def foo():

dec1, dec2, foo, (optional parameters)

• @staticmethod
• @classmethod
• @property
• @lru_cache
• @dataclass
• @staticmethod

• dec1
• dec2 can be any decorator names
• foo can be any valid function name
• parameters can be added.

Forgetting that decorators are applied bottom-to-top; forgetting parentheses for decorators that require arguments; applying decorators to undefined functions; missing return statement in decorated function.

Plain function definition (def foo():) vs decorated function; class decorators vs function decorators; decorator syntax vs annotation syntax in other languages.

Confusing decorator order (bottom-most applied first); confusing decorator syntax with type annotations or decorators in other languages.

• Python decorators
• function wrappers

The order of decorators matters: the decorator closest to the def is applied first (bottom-up).

Signals that the function's behavior will be modified or extended before it is invoked, indicating a design choice to separate cross-cutting concerns.

@dec1 @dec2 def foo():

def foo(*args, **kw): return func(*args, **kw)