如何从嵌套的 Json 中提取列表到 CSV？

Question

I make use of an API which outputs me adresses. However the adresses are nested as such:

{
   "totalItemCount":55,
   "pageCount":1,
   "size":100,
   "_links":{
      "self":{
         "href":"\/bag?filters[postcode]=1011PL&ovio-api-key=KEY"
      }
   },
   "_embedded":{
      "adres":[
         {
            "huisnummer":"7",
            "huisletter":"",
            "postcode":"1011PL",
            "huisnummertoevoeging":"",
            "openbareruimte":"Nieuwe Amstelstraat",
            "slug":"1011pl-nieuwe-amstelstraat-7",
            "woonplaats":"Amsterdam",
            "_links":{
               "self":{
                  "href":"\/bag\/1011pl-nieuwe-amstelstraat-7"
               }
            }
         },
         {
            "huisnummer":"25",
            "huisletter":"",
            "postcode":"1011PL",
            "huisnummertoevoeging":"",
            "openbareruimte":"Nieuwe Amstelstraat",
            "slug":"1011pl-nieuwe-amstelstraat-25",
            "woonplaats":"Amsterdam",
            "_links":{
               "self":{
                  "href":"\/bag\/1011pl-nieuwe-amstelstraat-25"
               }
            }
         },

My current script:

## Convert Output JSON to CSV
f = open("output.json", "r+")
x = json.loads(f.read())
f.close()
# print(x['_embedded']['adres'][0]['openbareruimte'])

f = csv.writer(open("test.csv", "w"))
f.writerow(["straat","huisnummer","postcode","stad"])
for y in x:
    f.writerow([x["_embedded"]["adres"][0]["openbareruimte"],
                x["_embedded"]["adres"][0]["huisnummer"],
                x["_embedded"]["adres"][0]["postcode"],
                x["_embedded"]["adres"][0]["woonplaats"]])

I want to output all of the streets, numbers, postal codes and cities to CSV, but it only outputs the first adress. I have tried using split and format but I'm too unfamiliar with that. If anyone knows how to make use of the nested data, it would be appreciated. I could not find any tutorial in regards.

Answer 1

You want to loop over items in x["_embedded"]["adres"] and write items for each y

for y in x["_embedded"]["adres"]:
    f.writerow(y["openbareruimte"],
               y["huisnummer"],
               y["postcode"],
               y["woonplaats"])

Answer 2

First, x seems to be a dictionary. So doing for y in x: ... will iterate over the keys. In this case it seems to be "totalItemsCount", "pageCount" etc. That's obviously not what you want because you aren't even using y .

The embedded field, as you've used it yourself, is x["_embedded"]["adres"] . As you have identified, it's an array of addresses. All you need to is go over it:

addresses = x["_embedded"]["adres"]
for address in addresses:
    f.writerow([address["openbareruimte"],
        address["huisnummer"],
        address["postcode"],
        address["woonplaats"]])

Few more comments about your code:

• When opening a file, you should always use it as a context manager so it will be closed: with open(...) as f: ... (the reason is that if an exception is raised during json loading, the file isn't closed properly).
• json can load directly from a file: json.load(f)

Considering the above two comments, the correct way to load the json is:

with open("output.json", "r+") as f:
    x = json.load(f)
# no need to call "f.close()"

with open("test.csv", "w") as f:
    writer = csv.writer(f)
    writer.writerow(["straat","huisnummer","postcode","stad"])
    addresses = x["_embedded"]["adres"]
    for address in addresses:
        f.writerow([address["openbareruimte"],
            address["huisnummer"],
            address["postcode"],
            address["woonplaats"]])

Answer 3

You need to iterate through the list in the loaded JSON data.

## Convert Output JSON to CSV

import csv, json

with open("output.json", "r") as f:
    x = json.load(f)

with open("subtract_test.csv", "w", newline="") as outp:
    f = csv.writer(outp)
    f.writerow(["straat","huisnummer","postcode","stad"]) # Header.

    for adres in x["_embedded"]["adres"]:
        f.writerow([adres["openbareruimte"],
                    adres["huisnummer"],
                    adres["postcode"],
                    adres["woonplaats"]])

print("Done")