[英]Accessing dictionary inside Python List
I have a list which contains dictionaries like this: 我有一个包含这样的字典的列表:
json_obj = [[{'id': None},{'id': '5b98d01c0835f23f538cdcab'},{'id': '5b98d0440835f23f538cdcad'},{'id': '5b98d0ce0835f23f538cdcb9'}],[{'id': None},{'id': '5b98d01c0835f23f538cd'},{'id': '5b98d0440835f23f538cd'},{'id': '5b98d0ce0835f23f538cdc'}]]
I want it to store in list of lists like this: 我希望它存储在这样的列表列表中:
y=[['None','5b98d01c0835f23f538cdcab','5b98d0440835f23f538cdcad','5b98d0ce0835f23f538cdcb9'],['None','5b98d01c0835f23f538cd','5b98d0440835f23f538cd','5b98d0ce0835f23f538cdc']]
For reading the id from the dictionary I tried 为了从字典中读取ID,我尝试了
for d in json_obj:
print(d['id'])
But I see this error with the above code: 但是我在上面的代码中看到了这个错误:
TypeError: list indices must be integers or slices, not str
You have a nested list of lists . 您有一个嵌套的列表列表 。 It sometimes helps to observe this visibly, note the nested []
syntax: 有时可以明显观察到这一点,请注意嵌套的[]
语法:
json_obj = [[{'id': None}, {'id': 'abc'}, {'id': 'def'}, {'id': 'ghi'}],
[{'id': None}, {'id': 'jkl'}, {'id': 'mno'}, {'id': 'pqr'}]]
Your syntax would works for single list: 您的语法适用于单个列表:
json_obj = [{'id': None}, {'id': 'abc'}, {'id': 'def'}, {'id': 'ghi'},
{'id': None}, {'id': 'jkl'}, {'id': 'mno'}, {'id': 'pqr'}]
for d in json_obj:
print(d['id'])
For nested lists, you can use itertools.chain.from_iterable
from the standard library: 对于嵌套列表,可以使用标准库中的itertools.chain.from_iterable
:
json_obj = [[{'id': None}, {'id': 'abc'}, {'id': 'def'}, {'id': 'ghi'}],
[{'id': None}, {'id': 'jkl'}, {'id': 'mno'}, {'id': 'pqr'}]]
from itertools import chain
for d in chain.from_iterable(json_obj):
print(d['id'])
Or, without an import you can use a nested for
loop: 或者,如果没有导入,则可以使用嵌套的for
循环:
for L in json_obj:
for d in L:
print(d['id'])
Using a nested list comprehension. 使用嵌套列表理解。
json_obj = [[{'id': None},{'id': '5b98d01c0835f23f538cdcab'},{'id': '5b98d0440835f23f538cdcad'},{'id': '5b98d0ce0835f23f538cdcb9'}],[{'id': None},{'id': '5b98d01c0835f23f538cd'},{'id': '5b98d0440835f23f538cd'},{'id': '5b98d0ce0835f23f538cdc'}]]
print( [[j["id"] for j in i] for i in json_obj] )
or 要么
for i in json_obj:
for j in i:
print(j["id"])
Output: 输出:
[[None, '5b98d01c0835f23f538cdcab', '5b98d0440835f23f538cdcad', '5b98d0ce0835f23f538cdcb9'], [None, '5b98d01c0835f23f538cd', '5b98d0440835f23f538cd', '5b98d0ce0835f23f538cdc']]
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