如何返回字典中的函数值

def hello():
    return "Hello, World!"

def goodbye():
    return "Goodbye!"

dictionary = {
    "greeting": hello,
    "farewell": goodbye
}

def get_function_result(dictionary, key):
    if key in dictionary and callable(dictionary[key]):
        function = dictionary[key]
        result = function()
        return result
    else:
        return None

function_value = get_function_result(dictionary, "greeting")
print(function_value)  # 输出 "Hello, World!"

function_value = get_function_result(dictionary, "farewell")
print(function_value)  # 输出 "Goodbye!"