Parse output of elasticsearch-py commands

I am writing on alerting functionality in Python using elasticsearch-py client. https://github.com/elastic/elasticserch-py. CatClient class has methods that I am interested in. I can see the output as stdout when I run my python code, however I want to parse the output and extract some details that I want. How do I do it? Is there any parameters that I can pass to get the output as list or json?

try format=json for the cat API. However you could also use the dedicated JSON APIs depending what data you are after.