How to create an element using values of already existed elements in a dict, inside a list? - list

Question

Here is my example:
print (stock_info)
>>> [{'symbol': 'AAPL', 'name': 'Apple Inc.', 'price': 145.16, 'quantity': 20}, {'symbol': 'AMZN', 'name': 'Amazon.com, Inc.', 'price': 998.61, 'quantity': 20}, {'symbol': 'FB', 'name': 'Facebook, Inc.', 'price': 152.96, 'quantity': 30}, {'symbol': 'GOOG', 'name': 'Alphabet Inc.', 'price': 957.01, 'quantity': 20}]
I have 'price' and 'quantity' fields with values.
And now I would like to create a field called 'total' = price * quantity
How to create a new field ('total': value) based on values of 2 fields, which already exist ( value = price * quantity)?
As a result I want to see:
>>> [{'symbol': 'AAPL', 'name': 'Apple Inc.', 'price': 145.16, 'quantity': 20, 'total' : 2903.2}, {'symbol': 'AMZN', 'name': 'Amazon.com, Inc.', 'price': 998.61, 'quantity': 20, 'total' : 19972.2}, {'symbol': 'FB', 'name': 'Facebook, Inc.', 'price': 152.96, 'quantity': 30, 'total' : 4588.8}, {'symbol': 'GOOG', 'name': 'Alphabet Inc.', 'price': 957.01, 'quantity': 20, 'total' : 19140.2}]
So each dict (dict, yes?) was extended with a new field 'total' and its value.
How to implement this idea?
Any help is greatly appreciated ;)
Thanks!

Answer 1

Just loop through your data and add a new key to your dictionaries:
for stock_item in stock_info:
stock_item["total"] = stock_item["price"] * stock_item["quantity"]
EDIT - Testing with your data:
stock_info = [{'symbol': 'AAPL', 'name': 'Apple Inc.', 'price': 145.16, 'quantity': 20},
{'symbol': 'AMZN', 'name': 'Amazon.com, Inc.', 'price': 998.61, 'quantity':20},
{'symbol': 'FB', 'name': 'Facebook, Inc.', 'price': 152.96, 'quantity': 30},
{'symbol': 'GOOG', 'name': 'Alphabet Inc.', 'price': 957.01, 'quantity': 20}]
for stock_item in stock_info:
stock_item["total"] = stock_item["price"] * stock_item["quantity"]
print(stock_info)
yields:
[{'name': 'Apple Inc.', 'price': 145.16, 'symbol': 'AAPL', 'total': 2903.2, 'quantity': 20},
{'name': 'Amazon.com, Inc.', 'price': 998.61, 'symbol': 'AMZN', 'total': 19972.2, 'quantity': 20},
{'name': 'Facebook, Inc.', 'price': 152.96, 'symbol': 'FB', 'total': 4588.8, 'quantity': 30},
{'name': 'Alphabet Inc.', 'price': 957.01, 'symbol': 'GOOG', 'total': 19140.2, 'quantity': 20}]