Source code for torchtext.data.functional
import re
import io
import torch
__all__ = [
"generate_sp_model", "load_sp_model",
"sentencepiece_numericalizer", "sentencepiece_tokenizer",
"numericalize_tokens_from_iterator"
]
"""
This file contains experimental functionality.
All of these are experimental, unstable, and subject to change or deletion.
"""
[docs]def generate_sp_model(filename, vocab_size=20000,
model_type="unigram",
model_prefix='m_user'):
r"""Train a SentencePiece tokenizer.
Args:
filename: the data file for training SentencePiece model.
vocab_size: the size of vocabulary (Default: 20,000).
model_type: the type of SentencePiece model, including unigram,
bpe, char, word.
model_prefix: the prefix of the files saving model and vocab.
Outputs:
The model and vocab are saved in two separate files with
model_prefix.
Examples:
>>> from torchtext.data.functional import generate_sp_model
>>> generate_sp_model('test.csv', vocab_size=23456, model_prefix='spm_user')
"""
torch.ops.torchtext.generate_sp_model(filename, vocab_size, model_type, model_prefix)
[docs]def load_sp_model(spm):
r"""Load a sentencepiece model for file.
Args:
spm: the file path or a file object saving the sentencepiece model.
Outputs:
output: a SentencePiece model.
Examples:
>>> from torchtext.data.functional import load_sp_model
>>> sp_model = load_sp_model("m_user.model")
>>> sp_model = load_sp_model(open("m_user.model", 'rb'))
"""
if isinstance(spm, str):
return torch.ops.torchtext.load_sp_model(spm)
elif isinstance(spm, io.BufferedReader):
return torch.ops.torchtext.load_sp_model_string(spm.read())
else:
raise TypeError(
f'Unsupported type for spm argument: {type(spm).__name__}. ' +
'Supported types are: ' +
', '.join([
'str', 'io.BufferedReader'
]))
[docs]def sentencepiece_numericalizer(sp_model):
r"""A sentencepiece model to numericalize a text sentence into
a generator over the ids.
Args:
sp_model: a SentencePiece model.
Outputs:
output: a generator with the input of text sentence and the output of the
corresponding ids based on SentencePiece model.
Examples:
>>> from torchtext.data.functional import sentencepiece_numericalizer
>>> sp_id_generator = sentencepiece_numericalizer(sp_model)
>>> list_a = ["sentencepiece encode as pieces", "examples to try!"]
>>> list(sp_id_generator(list_a))
[[9858, 9249, 1629, 1305, 1809, 53, 842],
[2347, 13, 9, 150, 37]]
"""
def _internal_func(txt_iter):
for line in txt_iter:
yield sp_model.EncodeAsIds(line)
return _internal_func
[docs]def sentencepiece_tokenizer(sp_model):
r"""A sentencepiece model to tokenize a text sentence into
a generator over the tokens.
Args:
sp_model: a SentencePiece model.
Outputs:
output: a generator with the input of text sentence and the output of the
corresponding tokens based on SentencePiece model.
Examples:
>>> from torchtext.data.functional import sentencepiece_tokenizer
>>> sp_tokens_generator = sentencepiece_tokenizer(sp_model)
>>> list_a = ["sentencepiece encode as pieces", "examples to try!"]
>>> list(sp_tokens_generator(list_a))
[['_sentence', 'piece', '_en', 'co', 'de', '_as', '_pieces'],
['_example', 's', '_to', '_try', '!']]
"""
def _internal_func(txt_iter):
for line in txt_iter:
yield sp_model.EncodeAsPieces(line)
return _internal_func
[docs]def custom_replace(replace_pattern):
r"""A transform to convert text string.
Examples:
>>> from torchtext.data.functional import custom_replace
>>> custom_replace_transform = custom_replace([(r'S', 's'), (r'\s+', ' ')])
>>> list_a = ["Sentencepiece encode aS pieces", "exampleS to try!"]
>>> list(custom_replace_transform(list_a))
['sentencepiece encode as pieces', 'examples to try!']
"""
_patterns = list((re.compile(p), r)
for (p, r) in replace_pattern)
def _internal_func(txt_iter):
for line in txt_iter:
for pattern_re, replaced_str in _patterns:
line = pattern_re.sub(replaced_str, line)
yield line
return _internal_func
[docs]def simple_space_split(iterator):
r"""A transform to split text string by spaces.
Examples:
>>> from torchtext.data.functional import simple_space_split
>>> list_a = ["Sentencepiece encode as pieces", "example to try!"]
>>> list(simple_space_split(list_a))
[['Sentencepiece', 'encode', 'as', 'pieces'], ['example', 'to', 'try!']]
"""
for line in iterator:
yield line.split()
[docs]def numericalize_tokens_from_iterator(vocab, iterator, removed_tokens=None):
r"""Yield a list of ids from an token iterator with a vocab.
Args:
vocab: the vocabulary convert token into id.
iterator: the iterator yield a list of tokens.
removed_tokens: removed tokens from output dataset (Default: None)
Examples:
>>> from torchtext.data.functional import simple_space_split
>>> from torchtext.data.functional import numericalize_tokens_from_iterator
>>> vocab = {'Sentencepiece' : 0, 'encode' : 1, 'as' : 2, 'pieces' : 3}
>>> ids_iter = numericalize_tokens_from_iterator(vocab,
>>> simple_space_split(["Sentencepiece as pieces",
>>> "as pieces"]))
>>> for ids in ids_iter:
>>> print([num for num in ids])
>>> [0, 2, 3]
>>> [2, 3]
"""
for tokens in iterator:
if removed_tokens is None:
yield iter(vocab[token] for token in tokens)
else:
yield iter(map(lambda x: vocab[x],
filter(lambda x: x not in removed_tokens, tokens)))
