def test_tree_basics(self):
tree = Tree(sample_tree)
assert str(tree) == sample_tree
assert tree.pretty_string() == sample_tree_pretty
assert tree.tokens() == ('This', 'is', 'a', 'fairly', 'simple',
'parse', 'tree', '.')
assert tree.tags() == ('DT', 'VBZ', 'DT', 'RB', 'JJ', 'NN', 'NN', '.')
assert tree.tokens_and_tags() == \
[('This', 'DT'), ('is', 'VBZ'), ('a', 'DT'), ('fairly', 'RB'),
('simple', 'JJ'), ('parse', 'NN'), ('tree', 'NN'), ('.', '.')]
assert tree.span() == (0, 8)
assert tree.label == 'S1'
subtrees = tree.subtrees()
assert len(subtrees) == 1
assert str(subtrees[0]) == '(S (NP (DT This)) (VP (VBZ is) (NP ' \
'(DT a) (ADJP (RB fairly) (JJ simple)) ' \
'(NN parse) (NN tree))) (. .))'
assert subtrees[0].label == 'S'
assert str(subtrees[0][0]) == '(NP (DT This))'
assert subtrees[0][0].label == 'NP'
assert subtrees[0][0].span() == (0, 1)
assert subtrees[0][0].tags() == ('DT', )
assert subtrees[0][0].tokens() == ('This', )
assert str(subtrees[0][0][0]) == '(DT This)'
assert subtrees[0][0][0].token == 'This'
assert subtrees[0][0][0].label == 'DT'
assert tree[0][0][0].is_preterminal()
assert len(tree[0]) == 3
subtrees = iter(tree[0])
assert str(next(subtrees)) == '(NP (DT This))'
assert str(next(subtrees)) == '(VP (VBZ is) (NP (DT a) (ADJP ' \
'(RB fairly) (JJ simple)) (NN parse) ' \
'(NN tree)))'
assert str(next(subtrees)) == '(. .)'
pairs = [(False, sample_tree),
(False, '(S (NP (DT This)) (VP (VBZ is) (NP (DT a) (ADJP '
'(RB fairly) (JJ simple)) (NN parse) (NN tree))) '
'(. .))'), (False, '(NP (DT This))'), (True, '(DT This)'),
(False, '(VP (VBZ is) (NP (DT a) (ADJP (RB fairly) (JJ '
'simple)) (NN parse) (NN tree)))'), (True, '(VBZ is)'),
(False, '(NP (DT a) (ADJP (RB fairly) (JJ simple)) (NN '
'parse) (NN tree))'), (True, '(DT a)'),
(False, '(ADJP (RB fairly) (JJ simple))'),
(True, '(RB fairly)'), (True, '(JJ simple)'),
(True, '(NN parse)'), (True, '(NN tree)'), (True, '(. .)')]
actual_pairs = [(subtree.is_preterminal(), str(subtree))
for subtree in tree.all_subtrees()]
assert pairs == actual_pairs
# index into a preterminal
self.assertRaises(IndexError, lambda: tree[0][0][0][0])
# index a child that doesn't exist
self.assertRaises(IndexError, lambda: tree[500])
self.assertRaises(IndexError, lambda: tree[0][0][7777])
self.assertRaises(IndexError, lambda: tree[-30])
# repr shouldn't crash, but we don't check (or rely on) its form
repr(tree)
repr(tree[0])
repr(tree[0][1])
repr(tree[0][1][0])
def ptb(line, words): t = Tree(line) forms = [] ptb_recurse(t.subtrees()[0], words, forms) return ' ' + ' '.join(forms) + ' '
def test_tree_basics(self):
tree = Tree(sample_tree)
assert str(tree) == sample_tree
assert tree.pretty_string() == sample_tree_pretty
assert tree.tokens() == ('This', 'is', 'a', 'fairly', 'simple',
'parse', 'tree', '.')
assert tree.tags() == ('DT', 'VBZ', 'DT', 'RB', 'JJ', 'NN',
'NN', '.')
assert tree.tokens_and_tags() == \
[('This', 'DT'), ('is', 'VBZ'), ('a', 'DT'), ('fairly', 'RB'),
('simple', 'JJ'), ('parse', 'NN'), ('tree', 'NN'), ('.', '.')]
assert tree.span() == (0, 8)
assert tree.label == 'S1'
subtrees = tree.subtrees()
assert len(subtrees) == 1
assert str(subtrees[0]) == '(S (NP (DT This)) (VP (VBZ is) (NP ' \
'(DT a) (ADJP (RB fairly) (JJ simple)) ' \
'(NN parse) (NN tree))) (. .))'
assert subtrees[0].label == 'S'
assert str(subtrees[0][0]) == '(NP (DT This))'
assert subtrees[0][0].label == 'NP'
assert subtrees[0][0].span() == (0, 1)
assert subtrees[0][0].tags() == ('DT',)
assert subtrees[0][0].tokens() == ('This',)
assert str(subtrees[0][0][0]) == '(DT This)'
assert subtrees[0][0][0].token == 'This'
assert subtrees[0][0][0].label == 'DT'
assert tree[0][0][0].is_preterminal()
assert len(tree[0]) == 3
subtrees = iter(tree[0])
assert str(next(subtrees)) == '(NP (DT This))'
assert str(next(subtrees)) == '(VP (VBZ is) (NP (DT a) (ADJP ' \
'(RB fairly) (JJ simple)) (NN parse) ' \
'(NN tree)))'
assert str(next(subtrees)) == '(. .)'
pairs = [(False, sample_tree),
(False, '(S (NP (DT This)) (VP (VBZ is) (NP (DT a) (ADJP '
'(RB fairly) (JJ simple)) (NN parse) (NN tree))) '
'(. .))'),
(False, '(NP (DT This))'),
(True, '(DT This)'),
(False, '(VP (VBZ is) (NP (DT a) (ADJP (RB fairly) (JJ '
'simple)) (NN parse) (NN tree)))'),
(True, '(VBZ is)'),
(False, '(NP (DT a) (ADJP (RB fairly) (JJ simple)) (NN '
'parse) (NN tree))'),
(True, '(DT a)'),
(False, '(ADJP (RB fairly) (JJ simple))'),
(True, '(RB fairly)'),
(True, '(JJ simple)'),
(True, '(NN parse)'),
(True, '(NN tree)'),
(True, '(. .)')]
actual_pairs = [(subtree.is_preterminal(), str(subtree))
for subtree in tree.all_subtrees()]
assert pairs == actual_pairs
# index into a preterminal
self.assertRaises(IndexError, lambda: tree[0][0][0][0])
# index a child that doesn't exist
self.assertRaises(IndexError, lambda: tree[500])
self.assertRaises(IndexError, lambda: tree[0][0][7777])
self.assertRaises(IndexError, lambda: tree[-30])
# repr shouldn't crash, but we don't check (or rely on) its form
repr(tree)
repr(tree[0])
repr(tree[0][1])
repr(tree[0][1][0])
