如何在MongoDB对象的Json内的Python中打印值

Question

I have this Json, and I need a value from a rate.

 "_id" : ObjectId("5addb57d0043582d48ba898a"),
"success" : true,
"timestamp" : 1524477784,
"base" : "EUR",
"date" : "2018-04-23",
"rates" : {
    "AED" : 4.492662,
    "AFN" : 85.576329,
    "ALL" : 128.39508,
    "AMD" : 586.837094,
    "ANG" : 2.177608,
    "AOA" : 267.092358,
    "ARS" : 24.678283,
    "AUD" : 1.602032,
    "AWG" : 2.177639,
    "AZN" : 2.079155,
    "BAM" : 1.958775,
    "BBD" : 2.446786,
    "BDT" : 101.517146,
    "BGN" : 1.943843,
    "BHD" : 0.460968,
    "NOK" : 9.626194,
 }

And this is my Python code

import pymongo

uri = "mongodb://127.0.0.1:27017"
client = pymongo.MongoClient(uri)
database = client['db']
collection = database['currency']
collection2 = database['countries']
p = str(input('Insert the country: ')).capitalize()

if p=='Norway':
currency = collection.find_one({'NOK'})
print(currency)

I want to print the value inside de NOK, how can I do it? Thanks in advance.

Answer 1

I think you can call it by :

currency = collection.find_one({"NOK"})
print(currency['rates']['NOK'])

Answer 2

What you're trying to do is fetch a value in a dictionary which is integrated inside of another dictionary. JSON returns are dictionaries.

I imagine that the collection variable contains the JSON return

One way of fetching this data is by calling the dictionary and telling it what key you want the dictionary to return, as the "NOK" key is in the "rates" key we will be calling the rates key first, then when the dictionary has returned the dictionary that contains the "NOK" key we will then pass the "NOK" key to that returned dictionary, so the code looks like this:

    currency = collection["rates"]["NOK"]

Another way of doing this is using the for loop, it is a lot longer but may help you understand.

    for key in collection:
        if key == "rates":
            for keyRates in JSON[key]:
                if keyRates == "NOK":
                     currency = JSON[key][keyRates]

Hope this helps