code-examples/update_list_object.py

#!/usr/bin/python

cart = [
	{'id': 1, 'name': 'Product1', 'price': '2000', 'quantity': 0},
	{'id': 2, 'name': 'Product2', 'price': '3000', 'quantity': 0}, 
	{'id': 3, 'name': 'Product3', 'price': '4000', 'quantity': 0}
]

print cart

readed = {'id': 1, 'name': 'Product1', 'price': '2000', 'quantity': 0}

print readed

index = cart.index(readed)

print index

cart[index]['quantity'] += 1

print cart