django-chunkator 2.0.0

Chunk large QuerySets into small chunks, and iterate over them without killing your RAM.

Chunk large QuerySets into small chunks, and iterate over them without killing your RAM.

Tested with all the combinations of:

• Python: 3.5, 3.6, 3.7, 3.8
• Django: 2, 2.1, 2.2, 3.0, master

Note

Django 3.0 is incompatible with Python 3.5, see <https://docs.djangoproject.com/en/3.0/releases/3.0/#python-compatibility>

Usage

from chunkator import chunkator
for item in chunkator(LargeModel.objects.all(), 200):
    do_something(item)

This tool is intended to work on Django querysets.

Your model must define a pk field (this is done by default, but sometimes it can be overridden) and this pk has to be unique. django- chunkator has been tested with PostgreSQL and SQLite, using regular PKs and UUIDs as primary keys.

You can also use values():

from chunkator import chunkator
for item in chunkator(LargeModel.objects.values('pk', 'name'), 200):
    do_something(item)

Important

If you’re using values() you have to add at least your “pk” field to the values, otherwise, the chunkator will throw a MissingPkFieldException.

Warning

This will not accelerate your process. Instead of having one BIG query, you’ll have several small queries. This will save your RAM instead, because you’ll not load a huge queryset result before looping on it.

If you want to manipulate the pages directly, you can use chunkator_page:

from chunkator import chunkator_page
queryset = LargeModel.objects.all().values('pk')
for page in chunkator_page(queryset, 200):
    launch_some_task([item['pk'] for item in page])

License

MIT License.