在python中定義嵌套字典

Question

我想在python中定義一個嵌套字典。 我嘗試了以下方法：

keyword = 'MyTest' # Later I want to pull this iterating through a list
key = 'test1'
sections = dict(keyword={}) #This is clearly wrong but how do I get the string representation?
sections[keyword][key] = 'Some value'

我可以做這個：

sections = {}
sections[keyword] = {}

但是在Pycharm中有一個警告說它可以通過字典標簽來定義。

有人可以指出如何實現這一目標嗎？

Answer 1

keyword = 'MyTest' # Later I want to pull this iterating through a list
key = 'test1'
sections = {keyword: {}} 
sections[keyword][key] = 'Some value'

print(sections)
{'MyTest': {'test1': 'Some value'}}

dict(keyword={})創建一個字符串"keyword"作為鍵而不是變量關鍵字的值。

In [3]: dict(foo={})
Out[3]: {'foo': {}}

使用dict文字實際上使用上面變量的值。

Answer 2

sections = {}

keyword = 'MyTest'
# If keyword isn't yet a key in the sections dict, 
# add it and set the value to an empty dict
if keyword not in sections:
    sections[keyword] = {} 

key = 'test1'
sections[keyword][key] = 'Some value'

另外，您可以使用defaultdict ，它將在第一次訪問關鍵字時自動創建內部字典

from collections import defaultdict

sections = defaultdict(dict)

keyword = 'MyTest'
key = 'test1'
sections[keyword][key] = 'Some value'