过滤一个dict的dict [英] Filter a dict of dict
问题描述
我有一个dict的dict,我想通过内部dict的密钥过滤:
a = { 'key1':{'id1':[0,1,2],'id2':[0,1,2],'id3':[4,5,6]}
'key2':{ 'id3':[0,1,2],'id4':[0,1,2]}
'key3':{'id3':[0,1,2],'id1':[ 4,5,6]}
}
例如,我想过滤 id1'to have:
result = {'key1':{'id1':[0,1,2]}
'key3':{'id1':[4,5,6]}
}
我已经尝试过滤器方法,我得到所有的值:
r = [('key1',{ 'id1':[0,1,2],'id2':[0,1,2],'id3':[4,5,6]})
('key3',{'id3' :[0,1,2],'id1':[4,5,6]})
]
此外,filter方法返回一个列表,我想保留格式为dict。
提前感谢
尝试这样:
>>>对于k,v ['id1'] for a.items()if'id1'in v}
{'key3':[4,5,6],'key1':[0, 1,2]}
对于Python 2.x,您可能更喜欢使用 iteritems()
而不是 items()
,你仍然需要一个漂亮的最近的python(2.7我认为)一个字典理解: pythons使用:
dict((k,v ['id1'])for k,v in a.iteritems()if 'id1'in v)
如果你想提取多个值,那么我认为你最好只是写完循环:
def query(data,wanted):
result = {}
for k,v in data.items():
v2 = {k2:v [k2]对于k2,如果k2在v中}
如果v2:
result [k] = v2
返回结果
给:
>>> query(a,('id1','id2'))
{'key3':{'id1':[4,5,6]},'key1':{'id2':[0,1 ,2],'id1':[0,1,2]}}
I new in Python and I am not sure it is a good idea to use dict of dict but here is my question. I have a dict of dict and I want to filter by the key of the inside dict:
a ={ 'key1' : {'id1' :[0,1,2] , 'id2' :[0,1,2], 'id3' :[4,5,6]}
'key2' : {'id3' :[0,1,2] , 'id4' :[0,1,2]}
'key3' : {'id3' :[0,1,2] , 'id1' :[4,5,6]}
}
For exemple , I want to filter by 'id1' to have :
result = { 'key1' : {'id1' :[0,1,2] }
'key3' : {'id1' :[4,5,6]}
}
I have tried the filter method by I get all the value:
r = [('key1' ,{'id1' :[0,1,2] , 'id2' :[0,1,2], 'id3' :[4,5,6]})
('key3' , {'id3' :[0,1,2] , 'id1' :[4,5,6]})
]
Furthermore the filter method returns a list and I want to keep the format as a dict.
Thanks in advance
Try this:
>>> { k: v['id1'] for k,v in a.items() if 'id1' in v }
{'key3': [4, 5, 6], 'key1': [0, 1, 2]}
For Python 2.x you might prefer to use iteritems()
instead of items()
and you'll still need a pretty recent python (2.7 I think) for a dictionary comprehension: for older pythons use:
dict((k, v['id1']) for k,v in a.iteritems() if 'id1' in v )
If you want to extract multiple values then I think you are best to just write the loops out in full:
def query(data, wanted):
result = {}
for k, v in data.items():
v2 = { k2:v[k2] for k2 in wanted if k2 in v }
if v2:
result[k] = v2
return result
giving:
>>> query(a, ('id1', 'id2'))
{'key3': {'id1': [4, 5, 6]}, 'key1': {'id2': [0, 1, 2], 'id1': [0, 1, 2]}}
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