Python 迭代字典列表并合并键同时保留值

Question

我正在尝试遍历字典列表并合并重复键（在本例中称为 'id'），移动值（重复键 'url'），从那个重复的实例，到第一个（保留的）实例作为值列表。

所以，从这里开始：

[{'id': ‘XYZ', 'url': ‘THIS IS A URL'}, 
{'id': ‘XYZ', 'url': ‘THIS IS A URL'},  
{'id': ‘XYZ', 'url': ‘THIS IS A URL'},  
{'id': ‘ABC', 'url': ‘THIS IS A URL'},  
{'id': ‘DEF', 'url': ‘THIS IS A URL'}]

为此：

[{'id': ‘XYZ', 'url': ‘THIS IS A URL', 'THIS IS A URL', 'THIS IS A URL'},
{'id': ‘ABC', 'url': ‘THIS IS A URL'},
{'id': ‘DEF', 'url': ‘THIS IS A URL'}]

Answer 1

您可以使用 defaultdict 将 id 映射到 url 列表，然后将其转换回原始对象。

import collections
id_to_url = collections.defaultdict(list)

urls = [{'id': 'XYZ', 'url': 'THIS IS A URL'}, 
{'id': 'XYZ', 'url': 'THIS IS A URL'},  
{'id': 'XYZ', 'url': 'THIS IS A URL'},  
{'id': 'ABC', 'url': 'THIS IS A URL'},  
{'id': 'DEF', 'url': 'THIS IS A URL'}]

for url in urls:
    id_to_url[url['id']].append(url['url'])

urls = [{'id': key, 'url': value} for key, value in id_to_url.items()]

结果：

>>> urls
[{'id': 'XYZ', 'url': ['THIS IS A URL', 'THIS IS A URL', 'THIS IS A URL']}, {'id': 'ABC', 'url': ['THIS IS A URL']}, {'id': 'DEF', 'url': ['THIS IS A URL']}]

Python 迭代字典列表并合并键同时保留值

Python to iterate list of dictionary and merge keys whilst retaining values

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