import re

正则表达式

作者：NightyNight
链接：https://www.zhihu.com/question/50356943/answer/308811523
来源：知乎
著作权归作者所有。商业转载请联系作者获得授权，非商业转载请注明出处。

def _reshape(shaper, recursive_types):

fn_lst = [_reshape(e, recursive_types) if e.__class__ in recursive_types else next for e in shaper]
ret_cls = shaper.__class__
def apply(itor):
    return ret_cls(fn(itor) for fn in fn_lst)
return apply

def reshape(shaper, recursive_types=(list, tuple, set)):

_apply = _reshape(shaper, set(recursive_types))
def apply(seq):
    return _apply(iter(seq))
return apply

shaper = [(1, 2, 3, 6), {2, 3, 6}, [2, [2]]]
print(shaper)

[(1, 2, 3, 6), {2, 3, 6}, [2, [2]]]

from collections import Iterable
flatten = lambda nested: list(filter(lambda _: _,

                                 (lambda _: ((yield from flatten(e)) if isinstance(e, Iterable) else (yield e) for e in _))(nested)))

lst = flatten(shaper)
print(lst)

[1, 2, 3, 6, 2, 3, 6, 2, 2]

reshaper = reshape(shaper)

print(reshaper(lst))

[(1, 2, 3, 6), {2, 3, 6}, [2, [2]]]

这个东西是parser。上面代码里的模型(reshape, _reshape)，我认为就是parser的精髓(话说上面这个确实可以直接拿来当parser用)