I have the following example json object and wish to return multiple key value pairs (by parsing the object either using a loop or some other method) and store these as the headed columns and rows in a dataframe.

I also want to be able to add a condition (preferably before the loop) to limit the dataset so that processing a much, much larger json dataset is quicker.

Here's the json:

 x = {
   "Data":[
      {
         "City":"Barcelona",
         "Country":"Spain",
         "Population":"1,620,343"
      },
      {
         "City":"Tokyo",
         "Country":"Japan",
         "Population":"14,043,239"
      },
      {
         "City":"Helsinki",
         "Country":"Finland",
         "Population":"658,864"
      },
      {
         "City":"Paris",
         "Country":"France",
         "Population":"2,165,423"
      },
      {
         "City":"Bologna",
         "Country":"Italy",
         "Population":"388,367"
      },
      {
         "City":"Verona",
         "Country":"Italy",
         "Population":"257,353"
      },
      {
         "City":"Cartagena",
         "Country":"Colombia",
         "Population":"914,552"
      }
   ]
}

I can return specifcic values using the following...

    output = [{element['City'], element['Country'], element['Population']} for element in x['Data']]
print(output)

which returns...

[{'1,620,343', 'Spain', 'Barcelona'}, {'14,043,239', 'Japan', 'Tokyo'}, {'Helsinki', '658,864', 'Finland'}, {'2,165,423', 'France', 'Paris'}, {'Italy', 'Bologna', '388,367'}, {'257,353', 'Verona', 'Italy'}, {'Colombia', 'Cartagena', '914,552'}]

1. Why is the order of the key value pairs not preserved? Some appears 'Population, Country, City', others appear as 'Country, City, Population' etc etc.

2. How might I transform this output to a dataframe for easier manipulation?

3. With a larger dataset, how might I add a condition to limit the volume so as to reduce the computational expense required to parse the json object?

Thanks

CodePudding user response：

Why is the order of the key value pairs not preserved? Some appears 'Population, Country, City', others appear as 'Country, City, Population' etc etc.

a