| Current File : //usr/lib/python3/dist-packages/babel/units.py |
from babel.core import Locale
from babel.numbers import format_decimal, LC_NUMERIC
class UnknownUnitError(ValueError):
def __init__(self, unit, locale):
ValueError.__init__(self, "%s is not a known unit in %s" % (unit, locale))
def get_unit_name(measurement_unit, length='long', locale=LC_NUMERIC):
"""
Get the display name for a measurement unit in the given locale.
>>> get_unit_name("radian", locale="en")
'radians'
Unknown units will raise exceptions:
>>> get_unit_name("battery", locale="fi")
Traceback (most recent call last):
...
UnknownUnitError: battery/long is not a known unit/length in fi
:param measurement_unit: the code of a measurement unit.
Known units can be found in the CLDR Unit Validity XML file:
https://unicode.org/repos/cldr/tags/latest/common/validity/unit.xml
:param length: "short", "long" or "narrow"
:param locale: the `Locale` object or locale identifier
:return: The unit display name, or None.
"""
locale = Locale.parse(locale)
unit = _find_unit_pattern(measurement_unit, locale=locale)
if not unit:
raise UnknownUnitError(unit=measurement_unit, locale=locale)
return locale.unit_display_names.get(unit, {}).get(length)
def _find_unit_pattern(unit_id, locale=LC_NUMERIC):
"""
Expand an unit into a qualified form.
Known units can be found in the CLDR Unit Validity XML file:
https://unicode.org/repos/cldr/tags/latest/common/validity/unit.xml
>>> _find_unit_pattern("radian", locale="en")
'angle-radian'
Unknown values will return None.
>>> _find_unit_pattern("horse", locale="en")
:param unit_id: the code of a measurement unit.
:return: A key to the `unit_patterns` mapping, or None.
"""
locale = Locale.parse(locale)
unit_patterns = locale._data["unit_patterns"]
if unit_id in unit_patterns:
return unit_id
for unit_pattern in sorted(unit_patterns, key=len):
if unit_pattern.endswith(unit_id):
return unit_pattern
def format_unit(value, measurement_unit, length='long', format=None, locale=LC_NUMERIC):
"""Format a value of a given unit.
Values are formatted according to the locale's usual pluralization rules
and number formats.
>>> format_unit(12, 'length-meter', locale='ro_RO')
u'12 metri'
>>> format_unit(15.5, 'length-mile', locale='fi_FI')
u'15,5 mailia'
>>> format_unit(1200, 'pressure-millimeter-ofhg', locale='nb')
u'1\\xa0200 millimeter kvikks\\xf8lv'
>>> format_unit(270, 'ton', locale='en')
u'270 tons'
Number formats may be overridden with the ``format`` parameter.
>>> import decimal
>>> format_unit(decimal.Decimal("-42.774"), 'temperature-celsius', 'short', format='#.0', locale='fr')
u'-42,8\\u202f\\xb0C'
The locale's usual pluralization rules are respected.
>>> format_unit(1, 'length-meter', locale='ro_RO')
u'1 metru'
>>> format_unit(0, 'length-mile', locale='cy')
u'0 mi'
>>> format_unit(1, 'length-mile', locale='cy')
u'1 filltir'
>>> format_unit(3, 'length-mile', locale='cy')
u'3 milltir'
>>> format_unit(15, 'length-horse', locale='fi')
Traceback (most recent call last):
...
UnknownUnitError: length-horse is not a known unit in fi
.. versionadded:: 2.2.0
:param value: the value to format. If this is a string, no number formatting will be attempted.
:param measurement_unit: the code of a measurement unit.
Known units can be found in the CLDR Unit Validity XML file:
https://unicode.org/repos/cldr/tags/latest/common/validity/unit.xml
:param length: "short", "long" or "narrow"
:param format: An optional format, as accepted by `format_decimal`.
:param locale: the `Locale` object or locale identifier
"""
locale = Locale.parse(locale)
q_unit = _find_unit_pattern(measurement_unit, locale=locale)
if not q_unit:
raise UnknownUnitError(unit=measurement_unit, locale=locale)
unit_patterns = locale._data["unit_patterns"][q_unit].get(length, {})
if isinstance(value, str): # Assume the value is a preformatted singular.
formatted_value = value
plural_form = "one"
else:
formatted_value = format_decimal(value, format, locale)
plural_form = locale.plural_form(value)
if plural_form in unit_patterns:
return unit_patterns[plural_form].format(formatted_value)
# Fall back to a somewhat bad representation.
# nb: This is marked as no-cover, as the current CLDR seemingly has no way for this to happen.
return '%s %s' % ( # pragma: no cover
formatted_value,
(get_unit_name(measurement_unit, length=length, locale=locale) or measurement_unit)
)
def _find_compound_unit(numerator_unit, denominator_unit, locale=LC_NUMERIC):
"""
Find a predefined compound unit pattern.
Used internally by format_compound_unit.
>>> _find_compound_unit("kilometer", "hour", locale="en")
'speed-kilometer-per-hour'
>>> _find_compound_unit("mile", "gallon", locale="en")
'consumption-mile-per-gallon'
If no predefined compound pattern can be found, `None` is returned.
>>> _find_compound_unit("gallon", "mile", locale="en")
>>> _find_compound_unit("horse", "purple", locale="en")
:param numerator_unit: The numerator unit's identifier
:param denominator_unit: The denominator unit's identifier
:param locale: the `Locale` object or locale identifier
:return: A key to the `unit_patterns` mapping, or None.
:rtype: str|None
"""
locale = Locale.parse(locale)
# Qualify the numerator and denominator units. This will turn possibly partial
# units like "kilometer" or "hour" into actual units like "length-kilometer" and
# "duration-hour".
numerator_unit = _find_unit_pattern(numerator_unit, locale=locale)
denominator_unit = _find_unit_pattern(denominator_unit, locale=locale)
# If either was not found, we can't possibly build a suitable compound unit either.
if not (numerator_unit and denominator_unit):
return None
# Since compound units are named "speed-kilometer-per-hour", we'll have to slice off
# the quantities (i.e. "length", "duration") from both qualified units.
bare_numerator_unit = numerator_unit.split("-", 1)[-1]
bare_denominator_unit = denominator_unit.split("-", 1)[-1]
# Now we can try and rebuild a compound unit specifier, then qualify it:
return _find_unit_pattern("%s-per-%s" % (bare_numerator_unit, bare_denominator_unit), locale=locale)
def format_compound_unit(
numerator_value, numerator_unit=None,
denominator_value=1, denominator_unit=None,
length='long', format=None, locale=LC_NUMERIC
):
"""
Format a compound number value, i.e. "kilometers per hour" or similar.
Both unit specifiers are optional to allow for formatting of arbitrary values still according
to the locale's general "per" formatting specifier.
>>> format_compound_unit(7, denominator_value=11, length="short", locale="pt")
'7/11'
>>> format_compound_unit(150, "kilometer", denominator_unit="hour", locale="sv")
'150 kilometer per timme'
>>> format_compound_unit(150, "kilowatt", denominator_unit="year", locale="fi")
'150 kilowattia / vuosi'
>>> format_compound_unit(32.5, "ton", 15, denominator_unit="hour", locale="en")
'32.5 tons per 15 hours'
>>> format_compound_unit(160, denominator_unit="square-meter", locale="fr")
'160 par m\\xe8tre carr\\xe9'
>>> format_compound_unit(4, "meter", "ratakisko", length="short", locale="fi")
'4 m/ratakisko'
>>> format_compound_unit(35, "minute", denominator_unit="fathom", locale="sv")
'35 minuter per famn'
>>> from babel.numbers import format_currency
>>> format_compound_unit(format_currency(35, "JPY", locale="de"), denominator_unit="liter", locale="de")
'35\\xa0\\xa5 pro Liter'
See https://www.unicode.org/reports/tr35/tr35-general.html#perUnitPatterns
:param numerator_value: The numerator value. This may be a string,
in which case it is considered preformatted and the unit is ignored.
:param numerator_unit: The numerator unit. See `format_unit`.
:param denominator_value: The denominator value. This may be a string,
in which case it is considered preformatted and the unit is ignored.
:param denominator_unit: The denominator unit. See `format_unit`.
:param length: The formatting length. "short", "long" or "narrow"
:param format: An optional format, as accepted by `format_decimal`.
:param locale: the `Locale` object or locale identifier
:return: A formatted compound value.
"""
locale = Locale.parse(locale)
# Look for a specific compound unit first...
if numerator_unit and denominator_unit and denominator_value == 1:
compound_unit = _find_compound_unit(numerator_unit, denominator_unit, locale=locale)
if compound_unit:
return format_unit(numerator_value, compound_unit, length=length, format=format, locale=locale)
# ... failing that, construct one "by hand".
if isinstance(numerator_value, str): # Numerator is preformatted
formatted_numerator = numerator_value
elif numerator_unit: # Numerator has unit
formatted_numerator = format_unit(
numerator_value, numerator_unit, length=length, format=format, locale=locale
)
else: # Unitless numerator
formatted_numerator = format_decimal(numerator_value, format=format, locale=locale)
if isinstance(denominator_value, str): # Denominator is preformatted
formatted_denominator = denominator_value
elif denominator_unit: # Denominator has unit
if denominator_value == 1: # support perUnitPatterns when the denominator is 1
denominator_unit = _find_unit_pattern(denominator_unit, locale=locale)
per_pattern = locale._data["unit_patterns"].get(denominator_unit, {}).get(length, {}).get("per")
if per_pattern:
return per_pattern.format(formatted_numerator)
# See TR-35's per-unit pattern algorithm, point 3.2.
# For denominator 1, we replace the value to be formatted with the empty string;
# this will make `format_unit` return " second" instead of "1 second".
denominator_value = ""
formatted_denominator = format_unit(
denominator_value, denominator_unit, length=length, format=format, locale=locale
).strip()
else: # Bare denominator
formatted_denominator = format_decimal(denominator_value, format=format, locale=locale)
# TODO: this doesn't support "compound_variations" (or "prefix"), and will fall back to the "x/y" representation
per_pattern = locale._data["compound_unit_patterns"].get("per", {}).get(length, {}).get("compound", "{0}/{1}")
return per_pattern.format(formatted_numerator, formatted_denominator)