How to add a new entry to a dictionary?-CodePudding

I have this json file:

[{"industry": "car", "price": 100.0, "earnings": 10.0, "name": "Volvo"}, 
{"industry": "car", "price": 280.0, "earnings": 11.0, "name": "Audi"}, 
{"industry": "car", "price": 190.0, "earnings": 7.0, "name": "Ferrari"}, 
{"industry": "Phone", "price": 90.0, "earnings": 2.0, "name": "Nokia"}, 
{"industry": "Phone", "price": 200.0, "earnings": 14.0, "name": "Samsung"}, 
{"industry": "Phone", "price": 40.0, "earnings": 7.0, "name": "Apple"}]

I printed the contents of the object using the method print. I calculated the price to earnings ratio (price/earnings) for each firm

This is my code:

import json
from pprint import pprint

with open('firm_list.json', encoding='utf-8') as data_file:
    data = json.loads(data_file.read())
pprint(data)
for item in data:
    pe= item['price']/item['earnings']
    print(pe)
data.update['price to earnings ratio'] = pe

I want to add price/earnings to the dictionary, but it doesn't work. Can you help me figure out what I'm doing wrong?

CodePudding user response：

Put the adding operation inside the loop

import json
from pprint import pprint


with open('firm_list.json', encoding='utf-8') as data_file:
    data = json.loads(data_file.read())
pprint(data)
for item in data:
    pe= item['price']/item['earnings']
    print(pe)
    item['price to earnings ratio'] = pe

CodePudding user response：

Try this one.

import json
from pprint import pprint

with open('firm_list.json', encoding='utf-8') as data_file:
    data = json.loads(data_file.read())
    
pprint(data)
for item in data:
    pe = item['price'] / item['earnings']
    item['price to earnings ratio'] = pe
    print(pe)

pprint(data)

CodePudding user response：

Instead of data.update you just have to use data['price']='new value'