searxng/searx/plugins/unit_converter.py
Markus Heiser 7f087496d2 WIP
Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>
2025-05-06 18:35:34 +02:00

158 lines
5.0 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>`.
"""
from __future__ import annotations
import typing
import re
import babel.numbers
from flask_babel import gettext, get_locale
from searx.wikidata_units import symbol_to_si
from searx.plugins import Plugin, PluginInfo
from searx.result_types import EngineResults
if typing.TYPE_CHECKING:
from searx.search import SearchWithPlugins
from searx.extended_types import SXNG_Request
from searx.plugins import PluginCfg
name = ""
description = gettext("")
plugin_id = ""
preference_section = ""
CONVERT_KEYWORDS = ["in", "to", "as"]
class SXNGPlugin(Plugin):
"""Convert between units. The result is displayed in area for the
"answers".
"""
id = "unit_converter"
def __init__(self, plg_cfg: "PluginCfg") -> None:
super().__init__(plg_cfg)
self.info = PluginInfo(
id=self.id,
name=gettext("Unit converter plugin"),
description=gettext("Convert between units"),
preference_section="general",
)
def post_search(self, request: "SXNG_Request", search: "SearchWithPlugins") -> EngineResults:
results = EngineResults()
# only convert between units on the first page
if search.search_query.pageno > 1:
return results
query = search.search_query.query
query_parts = query.split(" ")
if len(query_parts) < 3:
return results
for query_part in query_parts:
for keyword in CONVERT_KEYWORDS:
if query_part == keyword:
from_query, to_query = query.split(keyword, 1)
target_val = _parse_text_and_convert(from_query.strip(), to_query.strip())
if target_val:
results.add(results.types.Answer(answer=target_val))
return results
# 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
'''
def _parse_text_and_convert(from_query, to_query) -> str | None:
# pylint: disable=too-many-branches, too-many-locals
if not (from_query and to_query):
return None
measured = re.match(RE_MEASURE, from_query, re.VERBOSE)
if not (measured and measured.group('number'), measured.group('unit')):
return None
# 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 None
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 None
_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.##########;-#')
return f'{result} {target_symbol}'