Source code for pint

"""
    pint
    ~~~~

    Pint is Python module/package to define, operate and manipulate
    **physical quantities**: the product of a numerical value and a
    unit of measurement. It allows arithmetic operations between them
    and conversions from and to different units.

    :copyright: 2016 by Pint Authors, see AUTHORS for more details.
    :license: BSD, see LICENSE for more details.
"""

from __future__ import annotations

from importlib.metadata import version

from .errors import (  # noqa: F401
    DefinitionSyntaxError,
    DimensionalityError,
    LogarithmicUnitCalculusError,
    OffsetUnitCalculusError,
    PintError,
    RedefinitionError,
    UndefinedUnitError,
    UnitStrippedWarning,
)
from .formatting import formatter, register_unit_format
from .registry import ApplicationRegistry, LazyRegistry, UnitRegistry
from .util import logger, pi_theorem  # noqa: F401

# Default Quantity, Unit and Measurement are the ones
# build in the default registry.
Quantity = UnitRegistry.Quantity
Unit = UnitRegistry.Unit
Measurement = UnitRegistry.Measurement
Context = UnitRegistry.Context

try:  # pragma: no cover
    __version__ = version("pint")
except Exception:  # pragma: no cover
    # we seem to have a local copy not installed without setuptools
    # so the reported version will be unknown
    __version__ = "unknown"


#: A Registry with the default units and constants.
_DEFAULT_REGISTRY = LazyRegistry()

#: Registry used for unpickling operations.
application_registry = ApplicationRegistry(_DEFAULT_REGISTRY)


def _unpickle(cls, *args):
    """Rebuild object upon unpickling.
    All units must exist in the application registry.

    Parameters
    ----------
    cls : Quantity, Magnitude, or Unit
    *args

    Returns
    -------
    object of type cls

    """
    from pint.facets.plain import UnitsContainer

    for arg in args:
        # Prefixed units are defined within the registry
        # on parsing (which does not happen here).
        # We need to make sure that this happens before using.
        if isinstance(arg, UnitsContainer):
            for name in arg:
                application_registry.parse_units(name)

    return cls(*args)


def _unpickle_quantity(cls, *args):
    """Rebuild quantity upon unpickling using the application registry."""
    return _unpickle(application_registry.Quantity, *args)


def _unpickle_unit(cls, *args):
    """Rebuild unit upon unpickling using the application registry."""
    return _unpickle(application_registry.Unit, *args)


def _unpickle_measurement(cls, *args):
    """Rebuild measurement upon unpickling using the application registry."""
    return _unpickle(application_registry.Measurement, *args)


[docs]def set_application_registry(registry): """Set the application registry, which is used for unpickling operations and when invoking pint.Quantity or pint.Unit directly. Parameters ---------- registry : pint.UnitRegistry """ application_registry.set(registry)
[docs]def get_application_registry(): """Return the application registry. If :func:`set_application_registry` was never invoked, return a registry built using :file:`defaults_en.txt` embedded in the pint package. Returns ------- pint.UnitRegistry """ return application_registry
# Enumerate all user-facing objects # Hint to intersphinx that, when building objects.inv, these objects must be registered # under the top-level module and not in their original submodules __all__ = ( "Measurement", "Quantity", "Unit", "UnitRegistry", "PintError", "DefinitionSyntaxError", "LogarithmicUnitCalculusError", "DimensionalityError", "OffsetUnitCalculusError", "RedefinitionError", "UndefinedUnitError", "UnitStrippedWarning", "formatter", "get_application_registry", "set_application_registry", "register_unit_format", "pi_theorem", "__version__", "Context", )