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__",
)