1.2.1 lazy_property

The lazy_property decorator is meant to decorate functions that compute some constant value or property that you only want to compute once. The first call to the decorated function will run it and save the value (in memory) before returning it; subsequent calls will get this value without triggering the calculation.

You can think about it like a functools.lru_cache(maxsize=1) for functions with no parameters.

from decore import lazy_property

@lazy_property
def paramless_big_calc():
  """I take a lot of time!"""
  sub_res = [big_func(const) for const in array_of_constants]
  return sum(sub_res)

1.2.2 threadsafe_generator

The threadsafe_generator decorator makes generators threadsafe. This means multiple threads can be given references to the decorated generator and it is guaranteed that each item in the stream will be yielded (i.e. returned) to only a single thread.

from decore import threadsafe_generator

@threadsafe_generator
def user_documents(day):
  """I yield some MongoDB documents!"""
  client = get_mongodb_client(some_params)
  dt_obj = translate_day_to_dt(day)
  user_document_cursor = client.some_mongodb_query(dt_obj, SOME_CONST)
  while True:
    yield user_document_cursor.__next__()

1.3.1 Installing for development

Clone:

git clone git@github.com:shaypal5/decore.git

Install in development mode with test dependencies:

cd decore
pip install -e ".[test]"

1.3.2 Running the tests

To run the tests, use:

python -m pytest --cov=decore

1.3.3 Adding documentation

This project is documented using the numpy docstring conventions, which were chosen as they are perhaps the most widely-spread conventions that are both supported by common tools such as Sphinx and result in human-readable docstrings (in my personal opinion, of course). When documenting code you add to this project, please follow these conventions.