在Python中解析Json并找到一个值

Question

I am trying to parse following Json using Python and the json library

{"attributes":{"173":{"id":"173","code":"Size","label":"Size","options":[{"id":"352","label":"Footwear-41","products":["78834"]},{"id":"355","label":"Footwear-42","products":["78835"]},{"id":"357","label":"Footwear-42.5","products":["78836"]},{"id":"358","label":"Footwear-43","products":["78837"]},{"id":"361","label":"Footwear-44","products":["78838"]},{"id":"363","label":"Footwear-44.5","products":["78839"]},{"id":"364","label":"Footwear-45","products":["78840"]},{"id":"367","label":"Footwear-46","products":["78841"]}],"position":"0"}},"template":"<%- data.price %>\u00a0 \u20ac","currencyFormat":"%s\u00a0 \u20ac","optionPrices":{"78834":{"oldPrice":{"amount":189.9},"basePrice":{"amount":159.57983093277},"finalPrice":{"amount":189.9},"tierPrices":[]},"78835":{"oldPrice":{"amount":189.9},"basePrice":{"amount":159.57983093277},"finalPrice":{"amount":189.9},"tierPrices":[]},"78836":{"oldPrice":{"amount":189.9},"basePrice":{"amount":159.57983093277},"finalPrice":{"amount":189.9},"tierPrices":[]},"78837":{"oldPrice":{"amount":189.9},"basePrice":{"amount":159.57983093277},"finalPrice":{"amount":189.9},"tierPrices":[]},"78838":{"oldPrice":{"amount":189.9},"basePrice":{"amount":159.57983093277},"finalPrice":{"amount":189.9},"tierPrices":[]},"78839":{"oldPrice":{"amount":189.9},"basePrice":{"amount":159.57983093277},"finalPrice":{"amount":189.9},"tierPrices":[]},"78840":{"oldPrice":{"amount":189.9},"basePrice":{"amount":159.57983093277},"finalPrice":{"amount":189.9},"tierPrices":[]},"78841":{"oldPrice":{"amount":189.9},"basePrice":{"amount":159.57983093277},"finalPrice":{"amount":189.9},"tierPrices":[]}},"priceFormat":{"pattern":"%s\u00a0 \u20ac","precision":2,"requiredPrecision":2,"decimalSymbol":",","groupSymbol":".","groupLength":3,"integerRequired":1},"prices":{"oldPrice":{"amount":189.9},"basePrice":{"amount":159.57983093277},"finalPrice":{"amount":189.9}},"productId":"78842","chooseText":"Choose an Option...","images":[],"index":{"78834":{"173":"352"},"78835":{"173":"355"},"78836":{"173":"357"},"78837":{"173":"358"},"78838":{"173":"361"},"78839":{"173":"363"},"78840":{"173":"364"},"78841":{"173":"367"}},"sku":{"default":"CI6400-100","78834":"CI6400-100-Footwear-41","78835":"CI6400-100-Footwear-42","78836":"CI6400-100-Footwear-42.5","78837":"CI6400-100-Footwear-43","78838":"CI6400-100-Footwear-44","78839":"CI6400-100-Footwear-44.5","78840":"CI6400-100-Footwear-45","78841":"CI6400-100-Footwear-46"},"stock":{"78834":{"is_salable":true,"qty":1},"78835":{"is_salable":true,"qty":2},"78836":{"is_salable":true,"qty":3},"78837":{"is_salable":true,"qty":3},"78838":{"is_salable":true,"qty":3},"78839":{"is_salable":true,"qty":1},"78840":{"is_salable":true,"qty":3},"78841":{"is_salable":true,"qty":1}}}

I want to get the 'products' value for a specific footwear size, ex. if I want it for 42, find 78835.

I tried to do it in two ways:

1.

tex=THEJSONTEXT
jsn=json.loads(tex)
jsn['attributes']['173'].get("products","")

But this doesn't work for me. So I tried version 2:

import re
prod=re.findall('"Footwear-42","products":["\d\d\d\d\d"]', tex)

And even this didnt work for me....

Answer 1

Actually there is one more level of nesting. Try the below.

for i in jsn['attributes']['173']["options"]:
    print(i["products"])

Also the options is a list.

Answer 2

>>> jsn['attributes']['173'].keys()
dict_keys(['id', 'code', 'label', 'options', 'position'])

As you can see product isn't there, which is why the code isn't working. You're correctly parsing the JSON.

Formatting the JSON just a bit

{
  "attributes": {
    "173": {
      "id": "173",
      "code": "Size",
      "label": "Size",
      "options": [
        {
          "id": "352",
          "label": "Footwear-41",
          "products": [
            "78834"
          ]
        },
        {
          "id": "355",
          "label": "Footwear-42",
          "products": [
            "78835"
          ]
        },
        {
          "id": "357",
          "label": "Footwear-42.5",
          "products": [
            "78836"
          ]
        },

... much more

And it gets a little easier to drill down into the JSON. The only attribute I see relating to size is in the label key for the various options. Is that correct? If so, you'll have to filter on the keys then for the options list to do what you want.

so.. imagine the options list is assigned like this:

options = obj['attributes']['173']['options']

Then you can filter the list down to the products you want like this:

>>> size = 42
>>> list(filter(lambda x: x['label'][-1 * len(str(size)):] == str(size), options))
[{'id': '355', 'label': 'Footwear-42', 'products': ['78835']}]

---

so, what does lambda x: x['label'][-1 * len(str(size)):] do? It's a lambda which effectively does this:

size = 42
def filter_product(product_object):
    label = product_object['label']
    product_size = [-1 * len(str(size)):]  # get the last digits of the str that are the size
    if str(size) == product_size:
        return True
    else:
        return False

I look at the last n digits of the label based on how long the size float/int is. And then I compare that to the size you want, and if it is the same, then this is the product you're looking for.