def infer_language_pair(path):
    'Infer language pair from filename: <split>.<lang1>-<lang2>.(...).idx'
    (src, dst) = (None, None)
    for filename in PathManager.ls(path):
        parts = filename.split('.')
        if ((len(parts) >= 3) and (len(parts[1].split('-')) == 2)):
            return parts[1].split('-')
    return (src, dst)
Infer language pair from filename: <split>.<lang1>-<lang2>.(...).idx
def infer_language_pair(path):
    
    (src, dst) = (None, None)
    for filename in PathManager.ls(path):
        parts = filename.split('.')
        if ((len(parts) >= 3) and (len(parts[1].split('-')) == 2)):
            return parts[1].split('-')
    return (src, dst)