python - 抽象多个函数调用的优雅方式？

Question

例子:

>>> def write_to_terminal(fmt, *args):
...     print fmt % args
>>> LOG = logging.getLogger(__name__)
>>> info = multicall(write_to_terminal, LOG.info)
>>> debug = multicall(write_debug_to_terminal, LOG.debug)
>>> ...
>>> info('Hello %s', 'guido') # display in terminal *and* log the message

有没有一种优雅的方式来编写multicall？也许在标准库的帮助下......无需重新发明轮子？

Answer 1

是这样的吗？

def multicall(*functions):
    def call_functions(*args, **kwds):
        for function in functions:
            function(*args, **kwds)
    return call_functions

如果您想汇总结果:

def multicall(*functions):
    def call_functions(*args, **kwds):
        return [function(*args, **kwds) for function in functions]
    return call_functions

编辑

建议使用装饰器；在那种情况下，它看起来像这样:

def appendcalls(*functions):
    def decorator(decorated_function):
        all_functions = [decorated_function] + list(functions)
        def call_functions(*args, **kwds):
            for function in all_functions:
                function(*args, **kwds)
        return call_functions
    return decorator


LOG = logging.getLogger(__name__)

@appendcalls(LOG.info)
def info(fmt, *args):
    print fmt % args

info('Hello %s', 'guido')

appendcalls() 在装饰函数之后调用任意数量的函数。您可能希望以不同的方式实现装饰器，具体取决于您想要的返回值——来自装饰函数的原始值、所有函数结果的列表或什么都没有。