Python：将值添加到字典中的列表中

Question

Trying to add a value into weekdays:[0] from a variable called dow .

create_data = {"startDateTime":"2015-02-23T09:05:00-0600","endDateTime":"2015-02-23T10:05:00-0600","accessories":[],"customAttributes":[{"attributeId":"3","attributeValue":""},{"attributeId":"5","attributeValue":"Yes"}],"description":"Placeholder     Description","invitees":[],"participants":[],"recurrenceRule":[{"type":"weekly","interval":2,"weekdays":[0],"repeatTerminationDate":"2015-05-24T09:50:00-0600"}],"resourceId":"15","resources":["15"],"title":"","userId":"26","startReminder":"","endReminder":""}

I'm getting confused between adding into a dictionary and a list.

Tried the following but it churns out the error below;

create_data['recurrenceRule']['weekdays'] = dow

Below is the error.

Traceback (most recent call last):
  File "api.py", line 51, in <module>
    create_data['recurrenceRule']['weekdays'] = dow
TypeError: list indices must be integers, not str  

How do I access that value?

Answer 1

As value of create_data['recurrenceRule'] is list and list contains dictionary as item. So We have to get item from the list ie dictionary and add weekdays key in it.

create_data['recurrenceRule'][0]['weekdays'] = dow

Answer 2

create_data is a dictionary, recurrenceRule being one of its keys. Then, its value is a list:

>>> create_data['recurrenceRule']
[{'repeatTerminationDate': '2015-05-24T09:50:00-0600', 'interval': 2, 'type': 'weekly', 'weekdays': 2}]

So to change weekdays you firstly have to access to the first element in the list:

create_data['recurrenceRule'][0]['weekdays']=dow
                             ^^^

That's why you get this error:

create_data['recurrenceRule']['weekdays']
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: list indices must be integers, not str

Because you are trying to access to the index (0, 1, 2...) of a list with a string.