LibreTranslate/app/language.py

71 lines
2.3 KiB
Python

from argostranslate import translate
from polyglot.detect.base import Detector
languages = translate.load_installed_languages()
__lang_codes = [l.code for l in languages]
def detect_languages(text):
# detect batch processing
if isinstance(text, list):
is_batch = True
else:
is_batch = False
text = [text]
# get the candidates
candidates = []
for t in text:
candidates.extend(Detector(t).languages)
# total read bytes of the provided text
read_bytes_total = sum(c.read_bytes for c in candidates)
# only use candidates that are supported by argostranslate
candidate_langs = list(filter(lambda l: l.read_bytes != 0 and l.code in __lang_codes, candidates))
# this happens if no language could be detected
if not candidate_langs:
# use language "en" by default but with zero confidence
return [
{
'confidence': 0.0,
'language': "en"
}
]
# for multiple occurrences of the same language (can happen on batch detection)
# calculate the average confidence for each language
if is_batch:
temp_average_list = []
for lang_code in __lang_codes:
# get all candidates for a specific language
lc = list(filter(lambda l: l.code == lang_code, candidate_langs))
if len(lc) > 1:
# if more than one is present, calculate the average confidence
lang = lc[0]
lang.confidence = sum(l.confidence for l in lc) / len(lc)
lang.read_bytes = sum(l.read_bytes for l in lc)
temp_average_list.append(lang)
elif lc:
# otherwise just add it to the temporary list
temp_average_list.append(lc[0])
if temp_average_list:
# replace the list
candidate_langs = temp_average_list
# sort the candidates descending based on the detected confidence
candidate_langs.sort(key=lambda l: (l.confidence * l.read_bytes) / read_bytes_total, reverse=True)
return [
{
'confidence': l.confidence,
'language': l.code
}
for l in candidate_langs
]