def tokenize_with_offsets(self, text_input):
"""Performs basic word tokenization for BERT.
Args:
text_input: A `Tensor` or `RaggedTensor` of untokenized UTF-8 strings.
Returns:
A `RaggedTensor` of tokenized strings from text_input.
"""
# lowercase and strip accents (if option is set)
if self._lower_case:
text_input = case_fold_utf8(text_input)
text_input = normalize_utf8(text_input, "NFD")
text_input = string_ops.regex_replace(text_input, r"\p{Mn}", "")
else:
# utf8 normalization
if self._normalization_form is not None:
text_input = normalize_utf8(text_input,
self._normalization_form)
# strip out control characters
text_input = string_ops.regex_replace(text_input, r"\p{Cc}|\p{Cf}",
" ")
return regex_split_ops.regex_split_with_offsets(
text_input, _DELIM_REGEX_PATTERN, self._keep_delim_regex_pattern,
"BertBasicTokenizer")
def test_lowercase_empty_string(self):
txt = [
"",
]
expected = [
b"",
]
self.assertAllEqual(expected, normalize_ops.case_fold_utf8(txt))
def test_lowercase_one_string(self):
txt = [
" TExt to loWERcase! ",
]
expected = [
b" text to lowercase! ",
]
self.assertAllEqual(expected, normalize_ops.case_fold_utf8(txt))
def test_lowercase_text(self):
txt = [
"Punctuation and digits: -*/+$#%@%$123456789#^$*%&",
"Non-latin UTF8 chars: ΘͽʦȺЩ",
"Accented chars: ĎÔPQRŔSŠoóôpqrŕsštťuúvwxyý",
"Non-UTF8-letters: e.g. ◆, ♥, and the emoji symbol ( ͡° ͜ʖ ͡°)",
"Folded: ßς", ""
]
expected = [
"punctuation and digits: -*/+$#%@%$123456789#^$*%&",
"non-latin utf8 chars: θͽʦⱥщ",
"accented chars: ďôpqrŕsšoóôpqrŕsštťuúvwxyý",
"non-utf8-letters: e.g. ◆, ♥, and the emoji symbol ( ͡° ͜ʖ ͡°)",
"folded: ssσ", ""
]
self.assertAllEqual(expected, normalize_ops.case_fold_utf8(txt))
def tokenize(self, text_input):
"""Performs basic word tokenization for BERT.
Args:
text_input: A `Tensor` or `RaggedTensor` of untokenized UTF-8 strings.
Returns:
A `RaggedTensor` of tokenized strings from text_input.
"""
# lowercase and strip accents (if option is set)
if self._lower_case:
text_input = case_fold_utf8(text_input)
text_input = normalize_utf8(text_input, "NFD")
text_input = string_ops.regex_replace(text_input, r"\p{Mn}", "")
else:
# utf8 normalization
if self._normalization_form is not None:
text_input = normalize_utf8(text_input, self._normalization_form)
# strip out control characters
text_input = string_ops.regex_replace(text_input, r"\p{Cc}|\p{Cf}", " ")
# For chinese and emoji characters, tokenize by unicode codepoints
unicode_tokenizer = UnicodeScriptTokenizer(
keep_whitespace=self._keep_whitespace)
script_tokenized = unicode_tokenizer.tokenize(text_input)
split_cond = self._should_split(script_tokenized)
unicode_char_split = ragged_string_ops.unicode_split(
script_tokenized, "UTF-8")
unicode_split_tokens = array_ops.where(
array_ops.squeeze(split_cond),
y=array_ops.expand_dims(script_tokenized.values, axis=1),
x=unicode_char_split.values)
final_tokens = script_tokenized.with_flat_values(unicode_split_tokens)
return final_tokens.merge_dims(-2, -1)
def test_lowercase_one_string_ragged(self):
txt = ragged_factory_ops.constant([[" TExt ", "to", " loWERcase! "],
[" TExt to loWERcase! "]])
expected = [[b" text ", b"to", b" lowercase! "],
[b" text to lowercase! "]]
self.assertRaggedEqual(expected, normalize_ops.case_fold_utf8(txt))
def lower_case(self, text_input):
"""Lower-cases the `text_input'."""
text_input = case_fold_utf8(text_input)
text_input = normalize_utf8(text_input, "NFD")
text_input = string_ops.regex_replace(text_input, r"\p{Mn}", "")
return text_input
