Supervised training
thon

from transformers import PLBartForConditionalGeneration, PLBartTokenizer
tokenizer = PLBartTokenizer.from_pretrained("uclanlp/plbart-base", src_lang="en_XX", tgt_lang="python")
example_python_phrase = "def maximum(a,b,c):NEW_LINE_INDENTreturn max([a,b,c])"
expected_translation_english = "Returns the maximum value of a b c."
inputs = tokenizer(example_python_phrase, text_target=expected_translation_english, return_tensors="pt")
model(**inputs)

Generation
While generating the target text set the decoder_start_token_id to the target language id.