To query empty array in key using REST API

I’m running parse server 3.9.0/ dashboard 2.0.5

I am using django, so I use the REST API

I have a key which is Array type.
if the key value is (undefined), I can query with
params={ "where":json.dumps( {'list':None} ) }
to correctly get the results.

if the key value is an empty array [], I tried with
params={ "where":json.dumps( {'list':[]} ) }
which does not return the result.

I also tried
params={ "where":json.dumps( {'list':[None]} ) }
which gives me an error
‘code’: 107, ‘error’: ‘You cannot use as a query parameter.’

I want to know how can I query the empty list using REST API
Thanks

Try:

params={ "where":json.dumps( {'list':{'$eq':[]}} ) }