如何过滤 json 并打印到新的 json 文件中？
我有下面部分不完整的 python 代码，我试图用它来简单地解析这个 JSON 对象并将结果写入一个新的 json 文件，或者甚至将结果输出到控制台。
我只想返回包含price_catof的节点，并且如果可能的话，'C'我还想从每个对象中完全删除整个节点。'History'
我做错了什么以及我怎样才能简单地实现这一目标？
import json input_json = "" "
[
{
" type ": " 1 ",
" name ": " name 1 ",
"history":[
{
"expiration_date":"9999-12-31",
"effective_date":"2017-01-01"
}
],
"prices":[
{
"price":"3.00",
"price_cat":"C",
}
]
},
{
" type ": " 2 ",
" name ": " name 2 ",
"history":[
{
"expiration_date":"9999-12-31",
"effective_date":"2017-01-01"
}
],
"prices":[
{
"price":"3.00",
"price_cat":"A",
},
{
"price":"3.00",
"price_cat":"C",
}
]
},
{
" type ": " 1 ",
" name ": " name 3 ",
"history":[
{
"expiration_date":"9999-12-31",
"effective_date":"2017-01-01"
}
],
"prices":[
{
"price":"3.00",
"price_cat":"B",
}
]
}
]" ""
#Transform json input to python objects
input_dict = json.loads (input_json)
#Filter python objects with list comprehensions
output_dict =[x for x in input_dict if x['price_cat'] == 'C']
#Transform python object back into json
output_json = json.dumps (output_dict)
#Show json
print (output_json)
慕哥62875432回答
-
郎朗坤
您没有在字典中查找价格表：import jsoninput_json = """[ { " type ":" 1 ", " name ":" name 1 ", "history":[ { "expiration_date":"9999-12-31", "effective_date":"2017-01-01" } ], "prices":[ { "price":"3.00", "price_cat":"C" }] }, { " type ":" 2 ", " name ":" name 2 ", "history":[ { "expiration_date":"9999-12-31", "effective_date":"2017-01-01" }], "prices":[ { "price":"3.00", "price_cat":"A" }, { "price":"3.00", "price_cat":"C" } ] }, { " type ":" 1 ", " name ":" name 3 ", "history":[ { "expiration_date":"9999-12-31", "effective_date":"2017-01-01" } ], "prices":[ { "price":"3.00", "price_cat":"B" } ] }]"""#Transform json input to python objectsinput_dict = json.loads(input_json)#Filter python objects with list comprehensionsoutput_dict = []for input_subdict in input_dict: matching_prices = [] for price in input_subdict['prices']: if price['price_cat'] == 'C': matching_prices.append(price) if len(matching_prices) > 0: input_subdict['prices'] = matching_prices output_dict.append(input_subdict)#Transform python object back into jsonoutput_json = json.dumps(output_dict)#Show jsonprint (output_json)这会产生您正在寻找的答案：[ {" type ": " 1 ", " name ": " name 1 ", "history": [{"expiration_date": "9999-12-31", "effective_date": "2017-01-01"}], "prices": [{"price": "3.00", "price_cat": "C"}]}, {" type ": " 2 ", " name ": " name 2 ", "history": [{"expiration_date": "9999-12-31", "effective_date": "2017-01-01"}], "prices": [{"price": "3.00", "price_cat": "C"}]}] -
慕斯709654
在尝试查找价格类别之前，您似乎忘记将索引向下一级索引。这样写会很有帮助。parseObjects = []for jObject in input_json: for price in jObject["prices"]: if price["price_cat"] == "C": if "history" in jObject: del jObject["history"] parseObjects.append(jObject)发生在我们最好的人身上:)。
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