json_normalize JSON file with multiple levels of lists containing dictionary (sample included)

问题

(Originally from previous question but re-framed for the more general question)

This is a sample json file I'm working with with 2 records:

[{"Time":"2016-01-10",
"ID"
:13567,
"Content":{
    "Event":"UPDATE",
    "Id":{"EventID":"ABCDEFG"},
    "Story":[{
        "@ContentCat":"News",
        "Body":"Related Meeting Memo: Engagement with target firm for potential M&A.  Please be on call this weekend for news updates.",
        "BodyTextType":"PLAIN_TEXT",
        "DerivedId":{"Entity":[{"Id":"Amy","Score":70}, {"Id":"Jon","Score":70}]},
        "DerivedTopics":{"Topics":[
                            {"Id":"Meeting","Score":70},
                            {"Id":"Performance","Score":70},
                            {"Id":"Engagement","Score":100},
                            {"Id":"Salary","Score":70},
                            {"Id":"Career","Score":100}]
                        },
        "HotLevel":0,
        "LanguageString":"ENGLISH",
        "Metadata":{"ClassNum":50,
                    "Headline":"Attn: Weekend",
                    "WireId":2035,
                    "WireName":"IIS"},
        "Version":"Original"}
                ]},
"yyyymmdd":"20160110",
"month":201601},
{"Time":"2016-01-12",
"ID":13568,
"Content":{
    "Event":"DEAL",
    "Id":{"EventID":"ABCDEFG2"},
    "Story":[{
        "@ContentCat":"Details",
        "Body":"Test email contents",
        "BodyTextType":"PLAIN_TEXT",
        "DerivedId":{"Entity":[{"Id":"Bob","Score":100}, {"Id":"Jon","Score":70}, {"Id":"Jack","Score":60}]},
        "DerivedTopics":{"Topics":[
                            {"Id":"Meeting","Score":70},
                            {"Id":"Engagement","Score":100},
                            {"Id":"Salary","Score":70},
                            {"Id":"Career","Score":100}]
                        },
        "HotLevel":0,
        "LanguageString":"ENGLISH",
        "Metadata":{"ClassNum":70,
                    "Headline":"Attn: Weekend",
                    "WireId":2037,
                    "WireName":"IIS"},
        "Version":"Original"}
                ]},
"yyyymmdd":"20160112",
"month":201602}]

I'm trying to get to a dataframe at the level of the entity IDs (extracting Amy and Jon from record 1 and Bob, Jon, Jack from record 2). How do I do this? To clarify, the levels are (Content > Story > DerivedID > Entity > Id)

回答1:

With a list comprehension, you can reach down into that structure like:

with open('test.json', 'rU') as f:
    data = json.load(f)

df = pd.DataFrame(sum([i['Content']['Story'][0]['DerivedId']['Entity']
                       for i in data], []))

print(df)

Or if you have a lot of data and don't want to do the clunky sum() use itertools.chain.from_iterable like:

import itertools as it
df = pd.DataFrame.from_records(it.chain.from_iterable(
    i['Content']['Story'][0]['DerivedId']['Entity'] for i in data))

Results:

     Id  Score
0   Amy     70
1   Jon     70
2   Bob    100
3   Jon     70
4  Jack     60

来源：https://stackoverflow.com/questions/51236576/json-normalize-json-file-with-multiple-levels-of-lists-containing-dictionary-sa

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python

json

python-3.x

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normalize