If you're using Python, you might want to check out TinyDB. It's written in pure Python, and stores data in a json file. The helloworld should give you an idea of how simple it is.
# Setting up the database
>>> db = TinyDB('path/to/db.json')
# Adding records
>>> db.insert({'name': 'John', 'age': 22})
# Making queries
>>> User = Query()
>>> db.search(User.name == 'John')
[{'name': 'John', 'age': 22}]
It doesn't have advanced features, though. Be sure to read Why Not Use TinyDB? before you begin. I am yet to use it myself, so if you give it a try do tell me how it goes!