Source code for pint.errors

# -*- coding: utf-8 -*-
"""
    pint.errors
    ~~~~~~~~~

    Functions and classes related to unit definitions and conversions.

    :copyright: 2016 by Pint Authors, see AUTHORS for more details.
    :license: BSD, see LICENSE for more details.
"""
from __future__ import (division, unicode_literals, print_function,
                        absolute_import)

from .compat import string_types


class DefinitionSyntaxError(ValueError):
    """Raised when a textual definition has a syntax error.
    """

    def __init__(self, msg, filename=None, lineno=None):
        super(DefinitionSyntaxError, self).__init__()
        self.msg = msg
        self.filename = None
        self.lineno = None

    def __str__(self):
        mess = "While opening {}, in line {}: "
        return mess.format(self.filename, self.lineno) + self.msg


class RedefinitionError(ValueError):
    """Raised when a unit or prefix is redefined.
    """

    def __init__(self, name, definition_type):
        super(RedefinitionError, self).__init__()
        self.name = name
        self.definition_type = definition_type
        self.filename = None
        self.lineno = None

    def __str__(self):
        msg = "cannot redefine '{}' ({})".format(self.name,
                                                   self.definition_type)
        if self.filename:
            mess = "While opening {}, in line {}: "
            return mess.format(self.filename, self.lineno) + msg
        return msg


[docs]class UndefinedUnitError(AttributeError): """Raised when the units are not defined in the unit registry. """ def __init__(self, unit_names): super(UndefinedUnitError, self).__init__() self.unit_names = unit_names def __str__(self): mess = "'{}' is not defined in the unit registry" mess_plural = "'{}' are not defined in the unit registry" if isinstance(self.unit_names, string_types): return mess.format(self.unit_names) elif isinstance(self.unit_names, (list, tuple))\ and len(self.unit_names) == 1: return mess.format(self.unit_names[0]) elif isinstance(self.unit_names, set) and len(self.unit_names) == 1: uname = list(self.unit_names)[0] return mess.format(uname) else: return mess_plural.format(self.unit_names)
[docs]class DimensionalityError(ValueError): """Raised when trying to convert between incompatible units. """ def __init__(self, units1, units2, dim1=None, dim2=None, extra_msg=''): super(DimensionalityError, self).__init__() self.units1 = units1 self.units2 = units2 self.dim1 = dim1 self.dim2 = dim2 self.extra_msg = extra_msg def __str__(self): if self.dim1 or self.dim2: dim1 = ' ({})'.format(self.dim1) dim2 = ' ({})'.format(self.dim2) else: dim1 = '' dim2 = '' msg = "Cannot convert from '{}'{} to '{}'{}" + self.extra_msg return msg.format(self.units1, dim1, self.units2, dim2)
class OffsetUnitCalculusError(ValueError): """Raised on ambiguous operations with offset units. """ def __init__(self, units1, units2='', extra_msg=''): super(ValueError, self).__init__() self.units1 = units1 self.units2 = units2 self.extra_msg = extra_msg def __str__(self): msg = ("Ambiguous operation with offset unit (%s)." % ', '.join(['%s' % u for u in [self.units1, self.units2] if u]) + self.extra_msg) return msg.format(self.units1, self.units2) class UnitStrippedWarning(UserWarning): pass