Source code for calorine.env

from os import getenv




def calorine_getenv(variable) -> str:
    """Get value of environment variable, or default.

    Possible environment variables are:

    - `CALORINE_GPUMD_COMMAND` - Command used by
      :class:`GPUNEP <calorine.calculators.GPUNEP>` to invoke the ``gpumd``
      executable. Default: ``'gpumd'``.
    - `CALORINE_NEP_COMMAND` - Command used by :func:`batch_predict_properties
      <calorine.tools.batch_predict_properties>` to invoke the ``nep``
      executable. Default: ``'nep'``.

    Parameters
    ----------
    variable
        Name of variable, without the ``'CALORINE_'`` prefix.

    Returns
    -------
    Value of variable as string.
    """
    defaults = {'GPUMD_COMMAND': 'gpumd', 'NEP_COMMAND': 'nep'}

    if variable not in defaults:
        allowed = '\n'.join(f'  CALORINE_{var}' for var in defaults)
        raise ValueError(f'Environment variable CALORINE_{variable} is unknown. '
                         f'Allowed variables are:\n{allowed}')

    return getenv(f'CALORINE_{variable}', defaults[variable])