Python Decorators Explained: They Are Simply Functions Reassigning Names

Python decorators use the '@' symbol as syntactic sugar, which automatically reassigns a function to the result of passing it through another function. Code placed inside a decorator but outside its wrapper executes at decoration time, while the wrapper's code runs only when the decorated function is called. Stacked decorators apply from bottom to top, equivalent to nested function calls. Without using 'functools.wraps', decorators silently overwrite the original function's name and docstring, breaking debugging and documentation tools. Decorators that accept arguments are simply functions that return a decorator, adding one extra layer of nesting to the pattern.