python - 重复函数应用

Question

我遇到了以下问题:Write a recursive function repeatedlyApply that takes as arguments a function一个参数的 f 和一个正整数 n。 repeatedlyApply 的结果是一个参数的函数，它将 f 应用于该参数 n 次。

所以，例如，我们会有

repeatedlyApply(lambda x: x+1,10)(100) ==> 110

You may assume that the following function has been defined. You don't have to use it, but it can contribute to a pretty solution.

def compose(f,g):    return lambda x: f(g(x))

So far i've written this

def compose(f,g):
    return lambda x: f(g(x))

def recApply(f,n):
    for i in range(n):
        return recApply(compose(f,f), n-1)
    return f

我在某处出错了，因为使用上面的示例 recApply(lambda x: x+1,10)(100) 我得到 1124。

非常感谢帮助

Answer 1

正确答案是:

def recApply(func, n):
    if n > 1:
        rec_func = recApply(func, n - 1)
        return lambda x: func(rec_func(x))
    return func

输出:

>>>> print recApply(lambda x: x+1,10)(100)
110