





import re

from filelock import FileLock


try:
							import nltk

							UpperCAmelCase__						:			Union[str, Any]									=True
except (ImportError, ModuleNotFoundError):
							UpperCAmelCase__						:			Optional[int]									=False

if NLTK_AVAILABLE:
							with FileLock('''.lock''') as lock:
														nltk.download('''punkt''', quiet=True)





def      _lowercase					(						_UpperCAmelCase				)						->  str:
				re.sub("""<n>"""			,      """"""			,      _UpperCAmelCase				)  # remove pegasus newline char
				assert NLTK_AVAILABLE, "nltk must be installed to separate newlines between sentences. (pip install nltk)"
				return "\n".join(nltk.sent_tokenize(_UpperCAmelCase				)				)












def      _lowercase					(						_UpperCAmelCase			,      _UpperCAmelCase				)						->  list[str]:
				return [sentence[i : i + ngram_size] for i in range(len(_UpperCAmelCase				) - ngram_size + 1				)]


if __name__ == "__main__":
							from doctest import testmod

							testmod()





