[英]Collapse a nested dict into a list of dicts in python
I have an input nested dict as follows: 我有一个输入嵌套字典,如下所示:
{'name': 'Mark', 'marks':[{'english':20, 'maths':25},{'english':50, 'maths':55}]}
The output i am expecting is as follows: 我期望的输出如下:
[{'name': 'Mark', 'english':23, 'maths':35}, {{'name': 'Mark', 'english':50, 'maths':55}]
My code is as follows: 我的代码如下:
In [22]: input = {'name': 'Mark', 'marks':[{'english':20, 'maths':25},{'english':50, 'maths':55}]}
In [23]: marks = input.pop('marks')
In [24]: output = []
In [25]: for mark in marks:
...: output.append({**input, **mark})
...:
In [26]: output
Out[26]:
[{'english': 20, 'maths': 25, 'name': 'Mark'},
{'english': 50, 'maths': 55, 'name': 'Mark'}]
Works as expected.However, this works only for python 3.5 and above since {**x, **y} to merge 2 dicts was only introduced from that version on. 可以正常工作。但是,这仅适用于python 3.5及更高版本,因为{** x,** y}仅合并了该版本的2份字典。
Also my dataset is huge and I am not sure if this is the most efficient way to achieve this.What is the is best way to achieve this python 2.7. 另外我的数据集很大,我不确定这是否是实现此目标的最有效方法,什么是实现此python 2.7的最佳方法? I am also open to using external libraries like
Pandas
and numpy
. 我也愿意使用外部库,例如
Pandas
和numpy
。
Here's solution using pandas
: 这是使用
pandas
的解决方案:
import pandas as pd
x = {'name': 'Mark', 'marks':[{'english':20, 'maths':25},{'english':50, 'maths':55}]}
x = pd.DataFrame(x)
x = pd.concat([x['name'],x['marks'].apply(pd.Series)], axis=1)
print(x.to_dict(orient='records'))
Output: 输出:
[{'english': 20, 'name': 'Mark', 'maths': 25},
{'english': 50, 'name': 'Mark', 'maths': 55}]
PS: tested on python3 but it should work on python2.7 as well PS:在python3上测试过,但它也应该在python2.7上工作
Edit 编辑
More generic solution with additional key Now you don't have to hardcode the other keys. 带有附加密钥的更通用的解决方案现在,您不必对其他密钥进行硬编码。
x = {'name': 'Mark', 'add':'Mum','marks':[{'english':20, 'maths':25},{'english':50, 'maths':55}]}
x = pd.DataFrame(x)
cols = list(x.columns)
cols.remove('marks') # to get columns except `mark`
x = pd.concat([x[cols],x['marks'].apply(pd.Series)], axis=1)
print(x.to_dict(orient='records'))
Maybe simple list comprehension though with dirty hack to return the result: 也许是简单的列表理解,但是会返回结果:
input = {'name': 'Mark', 'marks':[{'english':20, 'maths':25},{'english':50, 'maths':55}]}
marks_list = input.pop('marks')
output = [marks.update(input) or marks for marks in marks_list]
[{'name': 'Mark', 'maths': 25, 'english': 20}, {'name': 'Mark', 'maths': 55, 'english': 50}]
I would use pydash ( https://pydash.readthedocs.io/en/latest/ ), it supports python 2.7: 我会使用pydash( https://pydash.readthedocs.io/en/latest/ ),它支持python 2.7:
from pydash import py_ as _
inputs = {'name': 'Mark', 'marks':[{'english':20, 'maths':25},{'english':50, 'maths':55}]}
def construct_dict(d1, d2):
d1.update(d2)
return d1
_(inputs['marks']).map(lambda x: construct_dict({ 'name': inputs['name'] }, x)).value()
# output
[{'maths': 25, 'name': 'Mark', 'english': 20}, {'maths': 55, 'name': 'Mark', 'english': 50}]
in python2.7 i would do the following: 在python2.7中,我将执行以下操作:
input = {'name': 'Mark', 'marks':[{'english':20, 'maths':25},{'english':50, 'maths':55}]}
marks = input.pop('marks')
output = map(lambda x:dict(input, **x), marks)
With python 2.7: 使用python 2.7:
idict = {'name': 'Mark', 'marks':[{'english':20, 'maths':25},{'english':50, 'maths':55}]}
print (idict)
marks = idict.pop("marks")
result = []
for each in marks:
result.append({'name': idict['name']})
for key, val in each.items():
result[-1][key] = val
print (result)
{'name': 'Mark', 'marks': [{'maths': 25, 'english': 20}, {'maths': 55, 'english': 50}]}
[{'maths': 25, 'name': 'Mark', 'english': 20}, {'maths': 55, 'name': 'Mark', 'english': 50}]
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