40 lines
1.3 KiB
Python
40 lines
1.3 KiB
Python
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import unittest
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import pytest
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from nltk import ConditionalFreqDist, tokenize
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class TestEmptyCondFreq(unittest.TestCase):
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def test_tabulate(self):
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empty = ConditionalFreqDist()
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self.assertEqual(empty.conditions(), [])
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with pytest.raises(ValueError):
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empty.tabulate(conditions="BUG") # nonexistent keys shouldn't be added
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self.assertEqual(empty.conditions(), [])
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def test_plot(self):
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empty = ConditionalFreqDist()
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self.assertEqual(empty.conditions(), [])
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empty.plot(conditions=["BUG"]) # nonexistent keys shouldn't be added
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self.assertEqual(empty.conditions(), [])
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def test_increment(self):
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# make sure that we can still mutate cfd normally
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text = "cow cat mouse cat tiger"
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cfd = ConditionalFreqDist()
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# create cfd with word length as condition
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for word in tokenize.word_tokenize(text):
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condition = len(word)
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cfd[condition][word] += 1
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self.assertEqual(cfd.conditions(), [3, 5])
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# incrementing previously unseen key is still possible
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cfd[2]["hi"] += 1
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self.assertCountEqual(cfd.conditions(), [3, 5, 2]) # new condition added
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self.assertEqual(
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cfd[2]["hi"], 1
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) # key's frequency incremented from 0 (unseen) to 1
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