This is a tiny wrapper around the json module in the Python standard library, allowing to read a json file incrementally.

This can be useful for

• parsing json streams without waiting for the end of the transmission,
• parsing very big json objects without wasting RAM for the json representation itself.

It is an alternative to ijson (written when I did not know ijson existed, but in the end more efficient).

No extensive tests were made (if you make them, let me know), but here are the results (in seconds) obtained in opening a local file with 384650 objects, totalling 174 MB:

Those results were obtained with the script “tests/json_load_test.py”.

Clearly those numbers are affected by the speed of the CPU and of the medium/stream. In general the faster the CPU (compared to the storage medium/stream), the faster will be the standard json compared to incremental ones (including jsaone).

Because it sounds similar to “json”… but the Saône is a (large) stream.

• simplejson (Python 2.5 only)
• for speedup: cython (at build time)

1. If you use Debian or a derivative (such as Ubuntu or Mint), you can simply use the packages provided above.
2. jsaone is on pypi, so you can install it with pip install jsaone
3. you can extract/clone the git repo, then move in the “jsaone” folder and give the command

python setup.py build_ext --inplace

import jsaone
with open('/path/to/my/file.json') as f:
    gen = jsaone.load(f)
    for i in gen:
        ...

You can browse the git repo here or clone with

git clone git://pietrobattiston.it/jsaone

For bugs and enhancements, just write me - me@pietrobattiston.it - ideally pointing to a git branch solving the issue/providing an enhancement.

Released under the GPL 3.