如何在 JSON 中保存元素的位置

Question

我有一个看起来像这样的JSON：

dummy = {
"fieldone": {
"fieldtwo": {
"yetanother": {
"another-nested-one": "the-deepest-nested"
}
}
}
}

为了访问特定元素，我会这样做：

s = dummy["fieldone"]["fieldtwo"]
print(s)
{'yetanother': {'another-nested-one': 'the-deepest-nested'}}

但是我的元素是深度嵌套的(当然比示例多得多(，所以我想以这种方式保存元素的路径：

path = ["fieldone"]["fieldtwo"]
test = dummy.get(path)
# or dummy[path]
# or dummy.path
print(test)   

当我运行它时，我收到以下消息：

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-12-57cff8dffc3a> in <module>
----> 1 path = ["fieldone"]["fieldtwo"]
2 test = dummy[path]
3 print(test)
TypeError: list indices must be integers or slices, not str

有没有办法保存元素的位置并在以后以这种方式检索它们？我可以通过无尽的链条来做到这一点，例如：

my_element = dummy["level_one"]["level_two"]["level_three"]

但我想知道是否有更优雅的方式来实现这一目标

Answer 1

你可以尝试这样的事情：

from functools import reduce
import operator
def getFromDict(dict, list):
return reduce(operator.getitem, list, dict) 

特别是，根据您的输入：

path = ["fieldone", "fieldtwo"]
print(getFromDict(dummy, path))
#output: {'yetanother': {'another-nested-one': 'the-deepest-nested'}}

Answer 2

你可以试试：

def get_by_path(my_dict, path):
if len(path) == 1:
return my_dict[path[0]]
return get_by_path(my_dict[path[0]], path[1:])

dummy = {
"fieldone": {
"fieldtwo": {
"yetanother": {
"another-nested-one": "the-deepest-nested"
}
}
}
}
my_path = ("fieldone", "fieldtwo")

print(get_by_path(dummy , my_path))

输出：

{'yetanother': {'another-nested-one': 'the-deepest-nested'}}