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.
"""

import sys

import pkg_resources

from .context import Context
from .errors import (
    DefinitionSyntaxError,
    DimensionalityError,
    OffsetUnitCalculusError,
    RedefinitionError,
    UndefinedUnitError,
    UnitStrippedWarning,
)
from .formatting import formatter
from .measurement import Measurement
from .quantity import Quantity
from .registry import LazyRegistry, UnitRegistry
from .unit import Unit
from .util import logger, pi_theorem

try:
    from pintpandas import PintArray, PintType

    del PintType
    del PintArray

    _HAS_PINTPANDAS = True
except ImportError:
    _HAS_PINTPANDAS = False
    _, _pintpandas_error, _ = sys.exc_info()

try:  # pragma: no cover
    __version__ = pkg_resources.get_distribution("pint").version
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.
_APP_REGISTRY = _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 .unit 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:
                _APP_REGISTRY.parse_units(name)

    return cls(*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 """ if not isinstance(registry, (LazyRegistry, UnitRegistry)): raise TypeError("Expected UnitRegistry; got %s" % type(registry)) global _APP_REGISTRY logger.debug("Changing app registry from %r to %r.", _APP_REGISTRY, registry) _APP_REGISTRY = 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 _APP_REGISTRY
def test(): """Run all tests. Returns ------- unittest.TestResult """ from .testsuite import run return run() # 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__ = ( "Context", "Measurement", "Quantity", "Unit", "UnitRegistry", "DefinitionSyntaxError", "DimensionalityError", "OffsetUnitCalculusError", "RedefinitionError", "UndefinedUnitError", "UnitStrippedWarning", "formatter", "get_application_registry", "set_application_registry", "pi_theorem", "__version__", )