python - 如何获取列表中的项目并将其转换为 json

Question

我有 4 个独立的 json，有 4 个键 sum、min、max、count，列表如下:

"sum" :  ["columnA", "columnB", "columnC", "columnD"]

"min" :  ["columnA", "columnC"]

"max" :  ["columnB", "columnC"]

"count" : ["columnA", "columnD"]

如何将它们重新打包成 json 对象，如下所示:

{ "columnA" : ["sum", "min","count" ] , "columnB" : ["sum", "max"], "columnC" : ["sum", "min", "max"] }

Answer 1

要获得快速(开发)结果，请尝试以下操作:

>>> my_json = {"sum" :  ["columnA", "columnB", "columnC", "columnD"]
,"min" :  ["columnA", "columnC"]
,"max" :  ["columnB", "columnC"]
,"count" : ["columnA", "columnD"]}
>>> result = {}
>>> [result.setdefault(col,[]).append(key) for key,value in my_json.items() for col in value]
>>> result
{'columnD': ['count', 'sum'], 'columnA': ['count', 'sum', 'min'], 'columnC': ['max', 'sum', 'min'], 'columnB': ['max', 'sum']}

更具可读性的版本:

>>> result = {}
>>> for function, columns in my_json.items():
        for column in columns:
            result.setdefault(column, []).append(function)


>>> result
{'columnD': ['count', 'sum'], 'columnA': ['count', 'sum', 'min'], 'columnC': ['max', 'sum', 'min'], 'columnB': ['max', 'sum']}