Using langdetect with a restricted set of languages

langdetect_restricted.py

from langdetect.detector_factory import DetectorFactory, PROFILES_DIRECTORY
import os

def get_factory_for(langs):
    df = DetectorFactory()
    profiles = []
    for lang in ['en', 'ru', 'pl']:
        with open(os.path.join(PROFILES_DIRECTORY, lang), 'r', encoding='utf-8') as f:
            profiles.append(f.read())
    df.load_json_profile(profiles)

    def _detect_langs(text):
        d = df.create()
        d.append(text)
        return d.get_probabilities()
      
    def _detect(text):
        d = df.create()
        d.append(text)
        return d.detect()
  
    df.detect_langs = _detect_langs
    df.detect = _detect
    return df

use_langdetect_restricted.py

from langdetect_restricted import get_factory_for
df = get_factory_for(['en', 'ru', 'pl'])
df.detect('today')         # 'en'
df.detect_langs('today')   # [en:0.9999988994459187]