Question

I have JSON documents of this type:

{ 
  name : 'John',
  age : 30,
  counts : [
    {day : monday, pay : 75, extra : 33} ,
    {day : tuesday, pay : 69, extra : 12} ,
    {day : sunday, pay : 42, extra : 0}  ]
 }

I want to iterate through them and perform actions. I have created a variable “a” as an attempt to iterate:

x = [2, 67, 53, 21, 5, ... ... ]

for i in db.docs.find():
    a = 0
    while a <= len(i['counts']):
        ...
        x.append(i['counts'][a]['extra']) 
        ...
        total = ...
        ...
        a = a + 1
        db.docs.update({'id': i['id']}, {'$set':{"counts.a.total":total}})

How can I make Python accept “a” as a list index?
Thank you for your help.

This is the error message:

Traceback (most recent call last):
    x.append(i['counts'][a]['extra'])
IndexError: list index out of range

Answer 1

You could just use a for loop:

for element in i['counts']:
    ...
    x.append(element['extra'])

If you must use a while loop, make sure the index is strictly lower than the length.

while a < len(i['counts']):