once_()

Creates a function that is restricted to execute `func` once. Subsequent calls return the value of the first invocation.

Implementation

Args: func: The function to execute. Returns: A new function that wraps `func`, ensuring it is only called once.

Example

                            def greet():
    return "Hello!"
greet_once = once_(greet)
greet_once()  # "Hello!"
greet_once()  # "Hello!"
                        

Expected output:

Source Code

                        def once_(func):

    called = False
    result = None
    def wrapper(*args, **kwargs):
        nonlocal called, result
        if not called:
            result = func(*args, **kwargs)
            called = True
        return result
    return wrapper
                    