Class-based decorator mechanics

Question

Accepted Answer

When Python sees `@MyClass`, it calls `MyClass(func)` at definition time, storing the result as the new function name. Calling the decorated function later triggers `instance.__call__(...)`, so the class must define `__call__` to make its instances behave like functions. `__init__` receives the original function when the class is instantiated, but `__call__` is what makes the resulting object invocable like a regular function.