mirror of
https://github.com/searxng/searxng.git
synced 2024-12-12 04:16:27 +00:00
263 lines
8.1 KiB
Python
263 lines
8.1 KiB
Python
# SPDX-License-Identifier: AGPL-3.0-or-later
|
|
"""A plugin for converting measured values from one unit to another unit (a
|
|
unit converter).
|
|
|
|
The plugin looks up the symbols (given in the query term) in a list of
|
|
converters, each converter is one item in the list (compare
|
|
:py:obj:`ADDITIONAL_UNITS`). If the symbols are ambiguous, the matching units
|
|
of measurement are evaluated. The weighting in the evaluation results from the
|
|
sorting of the :py:obj:`list of unit converters<symbol_to_si>`.
|
|
|
|
Enable in ``settings.yml``:
|
|
|
|
.. code:: yaml
|
|
|
|
enabled_plugins:
|
|
..
|
|
- 'Unit converter plugin'
|
|
|
|
"""
|
|
|
|
import re
|
|
import babel.numbers
|
|
from flask_babel import gettext, get_locale
|
|
|
|
from searx import data
|
|
|
|
|
|
name = "Unit converter plugin"
|
|
description = gettext("Convert between units")
|
|
default_on = True
|
|
|
|
plugin_id = "unit_converter"
|
|
preference_section = "general"
|
|
|
|
CONVERT_KEYWORDS = ["in", "to", "as"]
|
|
|
|
# inspired from https://stackoverflow.com/a/42475086
|
|
RE_MEASURE = r'''
|
|
(?P<sign>[-+]?) # +/- or nothing for positive
|
|
(\s*) # separator: white space or nothing
|
|
(?P<number>[\d\.,]*) # number: 1,000.00 (en) or 1.000,00 (de)
|
|
(?P<E>[eE][-+]?\d+)? # scientific notation: e(+/-)2 (*10^2)
|
|
(\s*) # separator: white space or nothing
|
|
(?P<unit>\S+) # unit of measure
|
|
'''
|
|
|
|
|
|
ADDITIONAL_UNITS = [
|
|
{
|
|
"si_name": "Q11579",
|
|
"symbol": "°C",
|
|
"to_si": lambda val: val + 273.15,
|
|
"from_si": lambda val: val - 273.15,
|
|
},
|
|
{
|
|
"si_name": "Q11579",
|
|
"symbol": "°F",
|
|
"to_si": lambda val: (val + 459.67) * 5 / 9,
|
|
"from_si": lambda val: (val * 9 / 5) - 459.67,
|
|
},
|
|
]
|
|
"""Additional items to convert from a measure unit to a SI unit (vice versa).
|
|
|
|
.. code:: python
|
|
|
|
{
|
|
"si_name": "Q11579", # Wikidata item ID of the SI unit (Kelvin)
|
|
"symbol": "°C", # symbol of the measure unit
|
|
"to_si": lambda val: val + 273.15, # convert measure value (val) to SI unit
|
|
"from_si": lambda val: val - 273.15, # convert SI value (val) measure unit
|
|
},
|
|
{
|
|
"si_name": "Q11573",
|
|
"symbol": "mi",
|
|
"to_si": 1609.344, # convert measure value (val) to SI unit
|
|
"from_si": 1 / 1609.344 # convert SI value (val) measure unit
|
|
},
|
|
|
|
The values of ``to_si`` and ``from_si`` can be of :py:obj:`float` (a multiplier)
|
|
or a callable_ (val in / converted value returned).
|
|
|
|
.. _callable: https://docs.python.org/3/glossary.html#term-callable
|
|
"""
|
|
|
|
|
|
ALIAS_SYMBOLS = {
|
|
'°C': ('C',),
|
|
'°F': ('F',),
|
|
'mi': ('L',),
|
|
}
|
|
"""Alias symbols for known unit of measure symbols / by example::
|
|
|
|
'°C': ('C', ...), # list of alias symbols for °C (Q69362731)
|
|
'°F': ('F', ...), # list of alias symbols for °F (Q99490479)
|
|
'mi': ('L',), # list of alias symbols for mi (Q253276)
|
|
"""
|
|
|
|
|
|
SYMBOL_TO_SI = []
|
|
|
|
|
|
def symbol_to_si():
|
|
"""Generates a list of tuples, each tuple is a measure unit and the fields
|
|
in the tuple are:
|
|
|
|
0. Symbol of the measure unit (e.g. 'mi' for measure unit 'miles' Q253276)
|
|
|
|
1. SI name of the measure unit (e.g. Q11573 for SI unit 'metre')
|
|
|
|
2. Factor to get SI value from measure unit (e.g. 1mi is equal to SI 1m
|
|
multiplied by 1609.344)
|
|
|
|
3. Factor to get measure value from from SI value (e.g. SI 100m is equal to
|
|
100mi divided by 1609.344)
|
|
|
|
The returned list is sorted, the first items are created from
|
|
``WIKIDATA_UNITS``, the second group of items is build from
|
|
:py:obj:`ADDITIONAL_UNITS` and items created from :py:obj:`ALIAS_SYMBOLS`.
|
|
|
|
If you search this list for a symbol, then a match with a symbol from
|
|
Wikidata has the highest weighting (first hit in the list), followed by the
|
|
symbols from the :py:obj:`ADDITIONAL_UNITS` and the lowest weighting is
|
|
given to the symbols resulting from the aliases :py:obj:`ALIAS_SYMBOLS`.
|
|
|
|
"""
|
|
|
|
global SYMBOL_TO_SI # pylint: disable=global-statement
|
|
if SYMBOL_TO_SI:
|
|
return SYMBOL_TO_SI
|
|
|
|
# filter out units which can't be normalized to a SI unit and filter out
|
|
# units without a symbol / arcsecond does not have a symbol
|
|
# https://www.wikidata.org/wiki/Q829073
|
|
|
|
for item in data.WIKIDATA_UNITS.values():
|
|
if item['to_si_factor'] and item['symbol']:
|
|
SYMBOL_TO_SI.append(
|
|
(
|
|
item['symbol'],
|
|
item['si_name'],
|
|
1 / item['to_si_factor'], # from_si
|
|
item['to_si_factor'], # to_si
|
|
item['symbol'],
|
|
)
|
|
)
|
|
|
|
for item in ADDITIONAL_UNITS:
|
|
SYMBOL_TO_SI.append(
|
|
(
|
|
item['symbol'],
|
|
item['si_name'],
|
|
item['from_si'],
|
|
item['to_si'],
|
|
item['symbol'],
|
|
)
|
|
)
|
|
|
|
alias_items = []
|
|
for item in SYMBOL_TO_SI:
|
|
for alias in ALIAS_SYMBOLS.get(item[0], ()):
|
|
alias_items.append(
|
|
(
|
|
alias,
|
|
item[1],
|
|
item[2], # from_si
|
|
item[3], # to_si
|
|
item[0], # origin unit
|
|
)
|
|
)
|
|
SYMBOL_TO_SI = SYMBOL_TO_SI + alias_items
|
|
return SYMBOL_TO_SI
|
|
|
|
|
|
def _parse_text_and_convert(search, from_query, to_query):
|
|
|
|
# pylint: disable=too-many-branches, too-many-locals
|
|
|
|
if not (from_query and to_query):
|
|
return
|
|
|
|
measured = re.match(RE_MEASURE, from_query, re.VERBOSE)
|
|
if not (measured and measured.group('number'), measured.group('unit')):
|
|
return
|
|
|
|
# Symbols are not unique, if there are several hits for the from-unit, then
|
|
# the correct one must be determined by comparing it with the to-unit
|
|
# https://github.com/searxng/searxng/pull/3378#issuecomment-2080974863
|
|
|
|
# first: collecting possible units
|
|
|
|
source_list, target_list = [], []
|
|
|
|
for symbol, si_name, from_si, to_si, orig_symbol in symbol_to_si():
|
|
|
|
if symbol == measured.group('unit'):
|
|
source_list.append((si_name, to_si))
|
|
if symbol == to_query:
|
|
target_list.append((si_name, from_si, orig_symbol))
|
|
|
|
if not (source_list and target_list):
|
|
return
|
|
|
|
source_to_si = target_from_si = target_symbol = None
|
|
|
|
# second: find the right unit by comparing list of from-units with list of to-units
|
|
|
|
for source in source_list:
|
|
for target in target_list:
|
|
if source[0] == target[0]: # compare si_name
|
|
source_to_si = source[1]
|
|
target_from_si = target[1]
|
|
target_symbol = target[2]
|
|
|
|
if not (source_to_si and target_from_si):
|
|
return
|
|
|
|
_locale = get_locale() or 'en_US'
|
|
|
|
value = measured.group('sign') + measured.group('number') + (measured.group('E') or '')
|
|
value = babel.numbers.parse_decimal(value, locale=_locale)
|
|
|
|
# convert value to SI unit
|
|
|
|
if isinstance(source_to_si, (float, int)):
|
|
value = float(value) * source_to_si
|
|
else:
|
|
value = source_to_si(float(value))
|
|
|
|
# convert value from SI unit to target unit
|
|
|
|
if isinstance(target_from_si, (float, int)):
|
|
value = float(value) * target_from_si
|
|
else:
|
|
value = target_from_si(float(value))
|
|
|
|
if measured.group('E'):
|
|
# when incoming notation is scientific, outgoing notation is scientific
|
|
result = babel.numbers.format_scientific(value, locale=_locale)
|
|
else:
|
|
result = babel.numbers.format_decimal(value, locale=_locale, format='#,##0.##########;-#')
|
|
|
|
search.result_container.answers['conversion'] = {'answer': f'{result} {target_symbol}'}
|
|
|
|
|
|
def post_search(_request, search):
|
|
# only convert between units on the first page
|
|
if search.search_query.pageno > 1:
|
|
return True
|
|
|
|
query = search.search_query.query
|
|
query_parts = query.split(" ")
|
|
|
|
if len(query_parts) < 3:
|
|
return True
|
|
|
|
for query_part in query_parts:
|
|
for keyword in CONVERT_KEYWORDS:
|
|
if query_part == keyword:
|
|
from_query, to_query = query.split(keyword, 1)
|
|
_parse_text_and_convert(search, from_query.strip(), to_query.strip())
|
|
return True
|
|
|
|
return True
|