Dynamic Inventory help

Hi,

I am trying to modify the fleet dynamic inventory. I have modified the fleet.py in github to generate a json like this

{
“all”: {
“nodetype1”: {
“hosts”: [“10.209.6.1”, “10.203.6.1”, “10.201.6.1”]
}
}
}

When I run this fleet.py with the ansible I get this error

ERROR! Attempted to execute “fleet.py” as inventory script: Inventory script (fleet.py) had an execution error:

May I know what is wrong with the above json?? I could not understand what is the wrong with the json by reading the documentation. Can someone help please?

Thanks,
./Siva