使用给定列表更新深度嵌套的字典

Question

我使用 Python 3.9，我有一个问题，我有一个列表：

keyList = ['a', 'b', 'c', 'd']

我也有一本字典，我想按以下方式编辑（更新）这本字典：

myDict = {}
#some code to add the keyList to myDict, this is my question, because I don't know...
myDict = {'a' : {'b' : {'c' : {'d' : 1}}}}

#or when myDict isn't equal to {}

myDict = {'a' : {'c' : 1}}
#same code to add the keyList to myDict
myDict = {'a' : {'c' : 1, 'b' : {'c' : {'d' : 1}}}}
#same code to add the keyList to myDict, but when it is created, add the +1 to value:
myDict = {'a' : {'c' : 1, 'b' : {'c' : {'d' : 2}}}}

Answer 1

IIUC，你可以迭代使用dict.setdefault：

def update_myDict(myDict):
    d = myDict
    for k in keyList:
        if k == keyList[-1]:
            d[k] = d.get(k, 0) + 1
        else:
            d = d.setdefault(k, {})
    return myDict

输出：

>>> update_myDict({})
{'a': {'b': {'c': {'d': 1}}}}

>>> update_myDict({'a' : {'c' : 1}})
{'a': {'c': 1, 'b': {'c': {'d': 1}}}}

>>> update_myDict({'a' : {'c' : 1, 'b' : {'c' : {'d' : 1}}}}) 
{'a': {'c': 1, 'b': {'c': {'d': 2}}}}

使用给定列表更新深度嵌套的字典

Update a deeply nested dictionary with a given list

python

dictionary

key