dials-data 0.4.0

DIALS Regression Data Manager

A python package providing data files used for regression tests in DIALS, dxtbx, xia2 and related packages.

Installation

To install this package in a normal Python environment, run:

install dials_data

To install in a DIALS installation you need to run:

libtbx.pip install dials_data

Usage

Tests that rely on the dials_data package will use it automatically once it is installed. You can also access the regression data using the command line interface:

dials.data

How do I run tests?

Tests using the dials_data package are presumably written using pytest. If they use the fixture provided by dials_data then you can run the tests with:

pytest --regression

How do I use this in my test?

If your test is written in pytest and you use the fixture provided by dials_data then you can use regression datasets in your test by adding the dials_data fixture to your test, ie:

def test_accessing_a_dataset(dials_data):
    location = dials_data("x4wide")

The fixture/variable dials_data in the test is a dials_data.download.DataFetcher instance, which can be called with the name of the dataset you want to access (here: x4wide). If the files are not present on the machine then they will be downloaded. If either the download fails or --regression is not specified then the test is skipped.

The return value (location) is a py.path.local object pointing to the directory containing the requested dataset.

How do I use this in my Python package?

Assuming you are using pytest then simply add the following to a file named conftest.py in the top level of your project:

import pytest
try:
    from dials_data import *
except ImportError:
    @pytest.fixture
    def dials_data():
        pytest.skip("Test requires python package dials_data")

Where are the regression datasets stored?

In order of evaluation:

• If the environment variable DIALS_DATA is set and exists or can be created then use that location

• If the file path /dls/science/groups/scisoft/DIALS/dials_data exists and is readable then use this location. This is a shared directory specific to Diamond Light Source

• If the environment variable LIBTBX_BUILD is set and the directory dials_data exists or can be created underneath that location then use that.

• Use ~/.cache/dials_data if it exists or can be created

• Otherwise fail with a RuntimeError

Credits

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