Spaces:
No application file
No application file
from transformers import M2M100ForConditionalGeneration, M2M100Tokenizer | |
from lingua import LanguageDetectorBuilder, Language | |
class Translator: | |
def __init__(self, languages:list=None, model_size:str='418M'): | |
"""Detects and translates text into a required language, using the | |
M2M100 model and the Lingua package. If the language is being detected | |
from a pool of possible languages these can be stated to improve | |
computational efficiency, otherwise leave blank to translate from any | |
language. | |
Args: | |
languages (list, optional): A list of potential source languages as | |
ISO-639-1 codes. Leave as None if source language is unknown. | |
Defaults to None. | |
model_str (str, optional): The model being used. Can be '418M' or | |
'1.2B'. Defaults to '418M'. | |
""" | |
if languages: | |
self.languages = [getattr(Language, l.upper()) for l in languages] | |
else: | |
self.languages = None | |
self.detector = self.get_detector() | |
self.model_str = f'facebook/m2m100_{model_size}' | |
self.model = M2M100ForConditionalGeneration.from_pretrained(self.model_str) | |
def get_detector(self)-> LanguageDetectorBuilder: | |
"""Retrieves the language detection model. If a list of potential | |
languages has been provided in the class initialisation then the | |
detector will chose from those classes. | |
Returns: | |
LanguageDetectorBuilder: initialised laguage detection model. | |
""" | |
if self.languages: | |
detector = LanguageDetectorBuilder.from_iso_codes_639_1(*self.languages) | |
else: | |
detector = LanguageDetectorBuilder.from_all_languages() | |
return detector.build() | |
def translate(self, text:str, out_lang:str)->str: | |
"""translates text to the language defined by out_lang. Source language | |
is detected automatically. | |
Args: | |
text (str): text to be translated | |
out_lang (str): ISO Code 639-1 of target language (e.g. "en") | |
Returns: | |
str: translated text in out_lang | |
""" | |
src_lang = self.detect_language(text) | |
src_tokenizer = self.get_tokenizer(src_lang) | |
src_tokens = src_tokenizer(text, return_tensors='pt') | |
out_tokens = self.model.generate(**src_tokens, forced_bos_token_id=src_tokenizer.get_lang_id(out_lang)) | |
out_text = src_tokenizer.batch_decode(out_tokens, skip_special_tokens=True) | |
return {'lanuage':src_lang, 'translation':out_text} | |
def get_tokenizer(self, src_lang:str)->M2M100Tokenizer: | |
"""Retrieves the tokenizer in the required source language. If the | |
Args: | |
src_lang (str): ISO0-639-1 country code | |
Returns: | |
M2M100Tokenizer: _description_ | |
""" | |
try: | |
return M2M100Tokenizer.from_pretrained(self.model_str, src_lang=src_lang) | |
except: | |
return M2M100Tokenizer.from_pretrained(self.model_str) | |
def detect_language(self, text:str)-> str: | |
"""USes the Lingua package to detect the language of the text. | |
Args: | |
text (str): text to be analyzed. | |
Returns: | |
str: iso-639-1 code of the detected language. | |
""" | |
lang = self.detector.detect_language_of(text) | |
return lang.iso_code_639_1.name.lower() |