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Python package to manage units for physical quantities

Project description

What is Barril?

Python package to manage units for physical quantities.

Quick example:

from barril.units import Scalar

s1 = Scalar(10, 'm')
s2 = Scalar(500, 'cm')
assert s1 + s2 == Scalar(15, 'm')


  • Pre-defined unit database containing several physical quantities for the Oil & Gas industry.
  • Data types with an associated unit: Scalar, Array, Quantity, FixedArray.
  • Automatic conversion during arithmetic operations.


For complete description of what type of contributions are possible, see the full CONTRIBUTING guide.

Here is a quick summary of the steps necessary to setup your environment to contribute to barril.

  1. Create a virtual environment and activate it:

    $ python -m virtualenv .env
    $ .env\Scripts\activate  # windows
    $ source .env/bin/activate  # linux


    If you use conda, you can install virtualenv in the root environment:

    $ conda install -n root virtualenv

    Don’t worry as this is safe to do.

  2. Update pip:

    $ python -m pip install -U pip
  3. Install development dependencies:

    $ pip install -e .[testing]
  4. Install pre-commit:

    $ pre-commit install
  5. Run tests:

    $ pytest --pyargs barril
  6. Generate docs locally:

    $ tox -e docs

    The documentation files will be generated in docs/_build.


A reminder for the maintainers on how to make a new release.

Note that the VERSION should folow the semantic versioning as X.Y.Z Ex.: v1.0.5

  1. Create a release-VERSION branch from upstream/master.
  2. Update CHANGELOG.rst.
  3. Push a branch with the changes.
  4. Once all builds pass, push a VERSION tag to upstream.
  5. Merge the PR.


This package was created with Cookiecutter and the audreyr/cookiecutter-pypackage project template.

1.10.0 (2020-10-22)

  • Removing thermodynamic temperature as default category for degF and degR units.

1.9.0 (2020-02-20)

  • New classmethod Array.FromScalars that creates an Array from a List[Scalar].
  • Add new unit: “barrel per second” (bbl/s).

1.8.0 (2020-01-10)

  • Add new category: “standard volume per standard volume”.
  • Move unit sm3/sm3 from “volume per volume” to “standard volume per standard volume”.

1.7.2 (2019-10-16)

  • _foundation has been renamed to _util, and a lot of functions which were not being used anymore have been removed.
  • Add new unit category mass temperature per mol (kg.K/mol).
  • Some units have been renamed as they were deemed out-of-place in the oil industry to something more usual (for example, 1000ft3/d became Mcf/d). The old representation of those units is still supported, but they will be automatically translated during Quantity creation, so this change should not affect users much.
  • Fix division 1.0 / a where a is a Scalar or Array and also add support for floor division, i.e., operations like a // b where a and b are Scalar or Array (and combinations with float or int).
  • Add new unit category for Joule-Thomson coefficient (K/Pa).
  • Add new temperature unit for density derivative in respect to temperature (kg/m3.K).

1.7.1 (2019-10-03)

  • Fixed bug in / and - operators for FixedArray.

1.7.0 (2019-06-18)

  • Add unit system.

1.6.1 (2019-04-11)

  • Change export to include ICurve and Curve and exclude IReadOnlyScalar.

1.6.0 (2019-04-10)

  • Add curve implementation.
  • Add support to interfaces from oop-ext.
  • Drop support to Python 2.

1.5.0 (2019-01-09)

  • Quantity.CheckValue now raises QuantityValidationError instead of ValueError.

1.4.0 (2018-12-17)

  • Add new category for “concentration ratio”.

1.3.0 (2018-10-13)

  • Add “per micrometre” unit to “per length” category.
  • Remove internal barril.fixtures module as it is not necessary or part of the public API.

1.2.0 (2018-09-26)

  • Add units for defining Spring-Dashpot movements.

1.1.0 (2018-09-24)

  • Add number and fraction properties to FractionValue.
  • Add unit read-only property to Quantity.

1.0.0 (2018-09-21)

  • First feature release.

0.1.0 (2018-09-03)

  • First release on PyPI.

Project details

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