How to post json file with pydruid?

Question

I went through pydruid documentation docs and could not find a single example where I can use the existing JSON file to convert it into a format which pydruid can use to post(start the job). We are using older version of druid so we may not have all the latest functionalities. I'm sure I might be able to achieve the same behavior with pycurl but somehow feel pydruid is a better approach here. Can someone post an example of how I can use the exiting JSON file with prdruid?