How to set a default value for null values in JMESPath query when using AWS CLI?

Question

I'm trying to run a command with AWS CLI with query. The command could be something simple like aws s3api list-buckets --query 'sum(Versions[*].Size)'

However, occasionally, some values can return null. In the example above, size can be null when there is nothing and the command will return the following error:

In function sum(), invalid type for value: None, expected one of: ['array-number'], received: "null"

How can I give it a default value? If the actual value is null, I would like to set it to 0 so that there is some value in the result instead of an error.

@Marcin I have tried that but it returns an error that `invalid token: Parse error at column 20, token "0" (NUMBER)` — Carven, Nov 03 '20 at 09:43
And this version `'sum(Versions[*].Size || [\`0\`])'`? Note back-quotes around 0. — Marcin, Nov 03 '20 at 09:47
No problem. If you don't mind, I provided an answer for future reference. — Marcin, Nov 03 '20 at 09:54

score 6 · Accepted Answer · answered Nov 03 '20 at 09:53

6

Based on the comments.

The solution was to use:

aws s3api list-buckets --query 'sum(Versions[*].Size || [`0`])'

answered Nov 03 '20 at 09:53

Marcin

215,873
14
235
294

How to set a default value for null values in JMESPath query when using AWS CLI?

1 Answers1