python-pmc-singleton

Python package for singleton class decorator.

Install

Regular use (assuming that you've already published your package on NCBI Artifactory PyPI):

pip install pmc-singleton  # or add it to your requirements file

For development:

git clone ssh://git@bitbucket.be-md.ncbi.nlm.nih.gov:9418/pmc/python-pmc-singleton.git
cd python-pmc-singleton
pip install -r requirements/test.txt -e .

Test

Test configuration is defined in the tox.ini file and includes py.test tests and flake8 source code checker.

You can run all of the tests:

python setup.py test

To run just the py.test tests, not flake8, and to re-use the current virtualenv:

py.test

API

Demo

The following example demonstrates the use of @singleton decorator.

>>> from pmc.singleton import singleton
>>> @singleton
... class YourClass:
...    pass
>>> instance_a = YourClass()
>>> instance_b = YourClass()
>>> instance_a is instance_b
True

As opposite example, where it is not used.

>>> class YourClass:
...    pass
>>> instance_a = YourClass()
>>> instance_b = YourClass()
>>> instance_a is not instance_b
True