python的可变长度参数(*args)在函数调用时扩展生成器吗？

Question

请考虑以下Python代码:

def f(*args):
    for a in args:
        pass

foo = ['foo', 'bar', 'baz']

# Python generator expressions FTW
gen = (f for f in foo)

f(*gen)

是否*args在通话时自动扩展发电机？换句话说,我在gen内部迭代两次f(*gen),一次扩展*args,一次迭代args？或者是生成器保持原始状态,而迭代只在for循环期间发生一次？

Answer 1

在函数调用时扩展生成器,因为您可以轻松检查:

def f(*args):
    print(args)
foo = ['foo', 'bar', 'baz']
gen = (f for f in foo)
f(*gen)

将打印

('foo', 'bar', 'baz')