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Testing Chinese Text Tokenization Possibilities in HanLP

This test suite validates the string utility functions in HanLP, specifically focusing on tokenization possibilities for Chinese text. It ensures the correct enumeration of all possible ways to segment a given Chinese string.

Test Coverage Overview

The test suite provides comprehensive coverage of the possible_tokenization function, which generates all possible segmentation combinations for Chinese text.

Key areas tested include:

Verification of the total number of possible tokenizations
Validation that all generated tokenizations maintain the original text when joined
Testing with a specific Chinese text example ‘商品和服务’

Implementation Analysis

The testing approach utilizes Python’s unittest framework with a focused test case structure. The implementation employs mathematical validation, checking that the number of possible tokenizations matches 2^(n-1) where n is the text length.

Key patterns include:

Assert statements for validation
Set operations for uniqueness checking
String manipulation for token verification

Technical Details

Testing infrastructure includes:

Python unittest framework
HanLP’s string_util module
possible_tokenization function
UTF-8 encoding support
Custom test class inheritance from unittest.TestCase

Best Practices Demonstrated

The test demonstrates several testing best practices including isolation of test cases, clear test method naming, and comprehensive assertion checking.

Notable practices:

Single responsibility principle in test methods
Explicit test case naming
Multiple assertion points for thorough validation
Clean test setup and organization

hankcs/hanlp

tests/test_string_util.py

            
# -*- coding:utf-8 -*-
# Author: hankcs
# Date: 2022-03-22 17:17
import unittest

from hanlp.utils.string_util import possible_tokenization


class TestStringUtility(unittest.TestCase):
    def test_enumerate_tokenization(self):
        text = '商品和服务'
        toks = possible_tokenization(text)
        assert len(set(toks)) == 2 ** (len(text) - 1)
        for each in toks:
            assert ''.join(each) == text


if __name__ == '__main__':
    unittest.main()