通过 JSON 文件中的 Python 访问字典中的列表

Question

I am new to Python and could use some help, please. I'm trying to use Python to read from my JSON file and get the values of the list within in a dictionary.

Once I read the JSON into my program, I have:

request body = {
  "providerName": "ProviderNameXYZ",
  "rateRequestPayments": [
    {
      "amount": 128.0,
      "creditorProfileId": "7539903942457444658",
      "debtorProfileId": "2072612712266192555",
      "paymentMethodId": "2646780961603748694016",
      "currency": "EUR",
      "userReference": "INVALID user ref automation single",
      "reconciliationId": "343546578753349"
    },
    {
      "amount": 129.0,
      "creditorProfileId": "7539903942457444658",
      "debtorProfileId": "2072612712266192555",
      "paymentMethodId": "2646780961603748694016",
      "currency": "EUR",
      "userReference": "INVALID user ref automation single",
      "reconciliationId": "343546578753340"
    }
  ]
}

1. I now want to be able to grab the value of any particular key. I've tried accessing it via several routes:

• rateRequestPayments[0].amount
• rateRequestPayments()[0].amount
• for k, v in request_body.rateRequestPayments(): print(k, v)
• for each in request_body.rateRequestPayments: print(each('amount'))
• values = eval(request_body['rateRequestPayments']) print(values[0]) All of these end up with errors. Per the 2nd comment below: request_body['rateRequestPayments'][0]['amount'] This works!

2. I also want to be able to delete the whole key-value pair ("amount": 128.0,) from the request_body. request_body['rateRequestPayments'][0]['amount'] does not work for this. Not sure how to reference this.

I know I am missing something simple but I'm just unsure what it is. Any help would be greatly appreciated.

Answer 1

Python is great for data science, and has many features that make it fit for the job. One of those features is finding data in a data set. body['rateRequestPayments'][<!WHICH DATA SET YOU WANT TO ACCESS>][<!VALUE YOU WANT TO FIND>]

Answer 2

First you'll need to put an underscore between requests and body so its requests_body = {...} .

To access a key-value pair:

requests_body["rateRequestPayments"] #to access the list of two dicts
requests_body["rateRequestPayments"][0] #to access the individual dicts by index
requests_body["rateRequestPayments"][0]["amount"] #to access the value of a particular key (in this case "amount" is the key)

To delete a key value pair, just use the del statement:

del requests_body["rateRequestPayments"][0]["amount"]

This will delete the key-value pair in the variable requests_body , so trying to access this key again will raise a KeyError error.

To access and delete a key-value pair, use .pop() :

value = requests_body["rateRequestPayments"][0].pop("amount")
#value is now 128.0 and the key-value pair is deleted