The read() method retrieves an existing object from a collection
returning the JSON document as a Python Dict. Actually read()
returns a touple made of a python dict and an error message.
If no error then the error message is an empty string.
An example we’re assuming there is a JSON document with a KEY of “r1”. Our collection name is “data.ds”
c_name = 'data.ds'
key = 'r1'
obj, err = dataset.read(c_name, key)
if err != '':
print(err)
else:
print(obj)