python - 使用其他嵌入的 JSON 对象展平 JSON 对象

Question

我有一个 JSON 对象，如下所示:

{
  "name":"bacon"
  "category":["food","meat","good"]
  "calories":"huge"
}

I am trying to flatten that into an array of unique values. I need to build a fact table for Tableau which is not able to work with cross-tabulated data or JSON data directly.

I am not picky about whether I do this in Python or Ruby, but so far I've been trying to do it in Ruby. I am able to easily parse the JSON and get a Ruby hash out of it which seems like the right thing to do first.

{"name"=>"bacon", "category"=>["food", "meat", "good"], "calories" => "huge"}

and I need to produce this:

name,category,calories
bacon,food,huge
bacon,meat,huge
bacon,good,huge

所以我认为我需要循环该哈希并尝试取消嵌套它。我一直在尝试这样的事情:

def Flatten(inHash)
    inHash.each do |key,value|
        if value.kind_of?(Hash)
            Flatten(value)
        else
            puts "#{value}"
        end 
    end 
end

但是，这似乎打印了所有值，但它不会重复之前的值。所以我得到的输出看起来像

bacon
food
meat
good
huge

是否有内置的方法、gem 或库可以实现这个或我正在从头开始构建？关于如何获得我想要的输出有什么想法吗？我会说 Ruby 和 Python，所以如果您有 Python 答案，请分享。

Answer 1

>>> #Assuming your json data is correctly formatted as is as follows
>>> data = '{ "name":"bacon", "category":["food","meat","good"], "calories":"huge" }'
>>> #Lets call our json parser as foo (I am bad with names)
>>> def foo(data):
    #You first need to parse it to a Py Object
    json_data = json.loads(data)
    from collections import namedtuple
    #Now create a namedtuple with the given keys of the dictionary
    food_matrix = namedtuple('food_matrix',json_data.keys())
    #And create a tuple out of the values
    data_tuple = food_matrix(*json_data.values())
    #Now with itertools.product create a cross product
    from itertools import product
    data_matrix = list(product([data_tuple.name],data_tuple.category, [data_tuple.calories]))
    # Now display the heading
    print "{:15}{:15}{:15}".format(["name","category","calories")
    # Now display the values
    for e in data_matrix:
        print "{:15}{:15}{:15}".format(*e)


>>> #Now call it
>>> foo(data)
name           category       calories                  
bacon          food           huge           
bacon          meat           huge           
bacon          good           huge           
>>>