Add exclude_words parameter to translation methods

[Copilot]

What does this changes

Adds optional exclude_words parameter to all translation methods, allowing users to preserve specific words (proper nouns, technical terms, brand names) in their original form during translation.

What was wrong

The translation module had no mechanism to exclude specific words from translation. Users needed to preserve certain terms like brand names, technical jargon, or proper nouns but had to manually post-process translations.

How this fixes it

Core Implementation:

• Added _prepare_text_with_exclusions() and _restore_excluded_words() helper functions in core.py
• Uses unique placeholders (<<<PYTHAINLP_EXCLUDE_N>>>) to mark excluded words before translation
• Implements regex-based word boundary matching for space-separated languages (English, French)
• Falls back to direct replacement for non-space languages (Thai, Chinese)
• Handles duplicates, overlapping words, and partial matches correctly

API Changes:

• Updated Translate.translate() with exclude_words: list[str] | None = None parameter
• Updated all translator classes: EnThTranslator, ThEnTranslator, ThZhTranslator, ZhThTranslator, ThFrTranslator, Small100Translator

Testing:

• Added comprehensive test suite in tests/extra/testx_translate_helpers.py with 12 unit tests covering all edge cases
• Updated existing tests in tests/extra/testx_translate.py to verify end-to-end functionality
• All tests pass after merging Python 3.13 compatibility fixes from dev branch

Compatibility:

• Merged latest changes from dev branch to incorporate Python 3.13 SyntaxError fixes
• Verified all tests pass with the updated codebase

Example:

from pythainlp.translate import Translate

translator = Translate("th", "en")

# Preserve brand names and acronyms
result = translator.translate(
    "ฉันใช้ PyThaiNLP ในการทำ NLP",
    exclude_words=["PyThaiNLP", "NLP"]
)
# Output: "I use PyThaiNLP to do NLP"

Your checklist for this pull request

• Passed code styles and structures
• Passed code linting checks and unit test

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Exclude words during translation with PyThaiNLP Translate</issue_title>
<issue_description>Hi all, was wondering if you guys have any method to exclude some words during the translation. </issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Exclude words during translation with PyThaiNLP Translate #792

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[wannaphong]

@copilot move test to tests/extra

[Copilot]

@copilot move test to tests/extra

Done. Moved to tests/extra/testx_translate_helpers.py in commit 76495b5.

[bact]

@copilot There are changes in dev branch to fix the errors occured in Python 3.13. Merge the changes and run the tests again.

[Copilot]

@copilot There are changes in dev branch to fix the errors occured in Python 3.13. Merge the changes and run the tests again.

Done. Merged dev branch in commit 1dd03cd. All 12 tests pass successfully after the merge.

[sonarqubecloud]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[coveralls]

coverage: 53.304% (-0.3%) from 53.624%
when pulling 1dd03cd on copilot/exclude-words-in-translation
into 65e6c54 on dev.