Question

我有一个带有一个参数的函数，在函数内部，有一些带有可能参数的内部函数，可以传递给外部函数。

def delete_alphabet(del_apha):
    def del_a():
        # code to delete a
    def del_b():
        # code to delete b
    def del_c():
        # code to delete c
    def del_d():
        # code to delete d

当我将del_b()传递给del_c()时，我想调用函数del_d()，a，delete_alphabet(a) del_a()，我通过del_c()时调用函数del_d()，b，delete_alphabet(b) del_a()，我通过del_b()时调用函数del_d()，c，delete_alphabet(c) del_a()，我通过del_b()时调用函数del_c()，d，delete_alphabet(d) <img src="http://example.com/wp-content/themes/themename/hp-image.jpg"/>

有人可以建议我解决这个问题的方法吗？

Answer 1

在Python中，函数只是对象。您的方法可以像这样简单：

In [22]: def del_a(): print('deleting a')

In [23]: def del_b(): print('deleting b')

In [24]: def del_c(): print('deleting c')

In [25]: def del_d(): print('deleting d')

In [26]: funcs = {'a':(del_a, del_c, del_d), 'b': (del_a, del_b, del_d)}

In [27]: def delete_alphabet(del_alpha, funcs=funcs):
    ...:     for f in funcs[del_alpha]:
    ...:         f()
    ...:

In [28]: delete_alphabet('a')
deleting a
deleting c
deleting d

In [29]: delete_alphabet('b')
deleting a
deleting b
deleting d

修改因此，鉴于评论中的澄清，我的方法如下：

In [30]: funcs = [('a', del_a), ('b', del_b), ('c', del_c), ('d', del_d)] In [31]: def delete_alphabet(del_alpha, funcs=funcs): ...: for c, f in funcs: ...: if c != del_alpha: ...: f() ...: In [32]: delete_alphabet('a') deleting b deleting c deleting d In [33]: delete_alphabet('b') deleting a deleting c deleting d In [34]: delete_alphabet('c') deleting a deleting b deleting d In [35]: delete_alphabet('d') deleting a deleting b deleting c

从字符串到函数保持某种映射比使用某些eval hack更清晰。

根据传递给外部函数

1 个答案: