def test_blank(self):
"""
does not allow blank lines from happening
"""
cp = CorpusParser()
results = list(cp.parse(self.blank))
self.assertEqual(0, len(results))
def splitter(sources):
res_train, res_test = defaultdict(dict), defaultdict(dict)
for source in sources:
# Parse corpus
parser = CorpusParser(input_dir=source, ldir="./log/")
parser.parse()
# Get and transform to DataFrame
reviews = parser.get_parsed()
reviews = pd.DataFrame(reviews)
# Split train/test
np.random.seed(42)
msk = np.random.rand(len(reviews)) < 0.8
train, test = reviews[msk], reviews[~msk]
# Retransform to dict
train, test = train.T.to_dict().values(), test.T.to_dict().values()
# Add to result
res_train[source] = train
res_test[source] = test
return res_train, res_test
def test_parse(self):
"""
will parse a brown corpus line using the standard / notation
"""
cp = CorpusParser()
null = CorpusParser.TagWord('START', 'START')
several = CorpusParser.TagWord('Several', 'ap')
defendants = CorpusParser.TagWord('defendants', 'nns')
period = CorpusParser.TagWord('.', '.')
expectations = [[null, several], [several, defendants],
[defendants, period]]
results = list(cp.parse(self.stream))
self.assertListEqual(expectations, results)
def test_parse(self):
"""will parse a brown corpus line using the standard / notation"""
cp = CorpusParser()
null = CorpusParser.TagWord('START', 'START')
several = CorpusParser.TagWord('Several', 'ap')
defendants = CorpusParser.TagWord('defendants', 'nns')
period = CorpusParser.TagWord('.', '.')
expectations = [
[null, several],
[several, defendants],
[defendants, period]
]
results = list(cp.parse(self.stream))
self.assertListEqual(expectations, results)
class POSTagger(object):
"""
This class is responsible for tagging new data given the corpus training data.
此類別針對已知語料訓練資料來標記新資料
"""
class LazyFile(object):
"""
The class wrapping an iterator of a file object in an iterator, which opens the file when iterated.
此類別在迭代器中包裝文件對象的迭代器 , 在迭代時打開該文件
"""
def __init__(self, filename):
self.filename = filename
self.file = None
def __iter__(self):
self.file = open(self.filename, 'r')
return self
def __next__(self):
try:
line = next(self.file)
except StopIteration as e:
self.file.close()
raise e
return line
def next(self):
return self.__next__()
@classmethod
def from_filepaths(cls, training_files, eager=False):
"""
Create POSTagger from list of file names
從文件名列表創建 POSTagger
:param training_files: list of file names
:param eager: boolean: train while opening
:return: POStagger
"""
lazy_files = [POSTagger.LazyFile(fn) for fn in training_files]
return POSTagger(lazy_files, eager)
def __init__(self, data_io=(), eager=False):
self.corpus_parser = CorpusParser()
self.data_io = data_io
self.trained = False
if eager:
self.train()
self.trained = True
def train(self):
if not self.trained:
self.tags = set()
self.tag_combos = defaultdict(int)
self.tag_frequencies = defaultdict(int)
self.word_tag_combos = defaultdict(int)
for io in self.data_io:
for line in io:
for ngram in self.corpus_parser.parse(line):
self.write(ngram)
self.trained = True
def write(self, ngram):
"""
:param ngram:
"""
if ngram[0].tag == 'START':
self.tag_frequencies['START'] += 1
self.word_tag_combos['START/START'] += 1
self.tags.add(ngram[-1].tag)
self.tag_frequencies[ngram[-1].tag] += 1
combo = ngram[-1].word + '/' + ngram[-1].tag
self.word_tag_combos[combo] += 1
combo = ngram[0].tag + '/' + ngram[-1].tag
self.tag_combos[combo] += 1
def viterbi(self, sentence):
sentence1 = re.sub(r'([\.\?!])', r' \1', sentence)
parts = re.split(r'\s+', sentence1)
last_viterbi = {}
backpointers = ['START']
for tag in self.tags:
if tag == 'START':
continue
else:
probability = self.tag_probability('START', tag) \
* self.word_tag_probability(parts[0], tag)
if probability > 0:
last_viterbi[tag] = probability
if len(last_viterbi) > 0:
backpointer = max(last_viterbi,
key=(lambda key: last_viterbi[key]))
else:
backpointer = max(self.tag_frequencies,
key=(lambda key: self.tag_frequencies[key]))
backpointers.append(backpointer)
for part in parts[1:]:
viterbi = {}
for tag in self.tags:
if tag == 'START':
continue
if len(last_viterbi) == 0:
break
best_tag = max(last_viterbi,
key=(lambda prev_tag: last_viterbi[prev_tag] *
self.tag_probability(prev_tag, tag) * self.
word_tag_probability(part, tag)))
probability = last_viterbi[best_tag] * \
self.tag_probability(best_tag, tag) * \
self.word_tag_probability(part, tag)
if probability > 0:
viterbi[tag] = probability
last_viterbi = viterbi
if len(last_viterbi) > 0:
backpointer = max(last_viterbi,
key=(lambda key: last_viterbi[key]))
else:
backpointer = max(self.tag_frequencies,
key=(lambda key: self.tag_frequencies[key]))
backpointers.append(backpointer)
return backpointers
def tag_probability(self, previous_tag, current_tag):
"""Maximum likelihood estimate 最大概率估算
count(previous_tag, current_tag) / count(previous_tag)"""
denom = self.tag_frequencies[previous_tag]
if denom == 0:
return 0
else:
return self.tag_combos[previous_tag + '/' +
current_tag] / float(denom)
def word_tag_probability(self, word, tag):
"""Maximum Likelihood estimate 最大概率估算
count (word and tag) / count(tag)"""
denom = self.tag_frequencies[tag]
if denom == 0:
return 0
else:
return self.word_tag_combos[word + '/' + tag] / float(denom)
def probability_of_word_tag(self, words, tags):
if len(words) != len(tags):
raise ValueError('The word and tags must be the same length!')
length = len(words)
probability = 1.0
for i in range(1, length):
probability *= self.tag_probability(tags[i - 1], tags[i]) * \
self.word_tag_probability(words[i], tags[i])
return probability
import sys
sys.path.append('./src/')
from corpus_parser import CorpusParser
from corpus_attributes import CorpusAttributes
from time import clock
# Pick the corpus to parse
corpus_parser = CorpusParser(sys.argv)
# Parse it
corpus_parser.parse()
# Create the attributes object
corpus_attributes = CorpusAttributes(corpus_parser)
# Get aggregate statistics on attributes over time
corpus_attributes.get_attributes()
corpus_attributes.get_stats(sys.argv[3])
corpus_attributes.print_stats()
def test_blank(self):
"""does not allow blank lines from happening"""
cp = CorpusParser()
results = list(cp.parse(self.blank))
self.assertEqual(0, len(results))
import sys
sys.path.append('./src/')
from corpus_parser import CorpusParser
from naive_sentiment import NaiveSentiment
# Pick the corpus to parse
corpus_parser = CorpusParser(sys.argv)
# Parse it
corpus_parser.parse()
# Get stats for the particular corpus
naive_sentiment = NaiveSentiment(corpus_parser)
# Parse articles for content words and print their frequencies
naive_sentiment.get_stats()
naive_sentiment.print_stats()
class POSTagger(object):
"""
This class is responsible for tagging new data given the corpus training data.
"""
class LazyFile(object):
"""
The class wrapping an iterator of a file object in an iterator, which opens the file when iterated.
"""
def __init__(self, filename):
self.filename = filename
self.file = None
def __iter__(self):
self.file = open(self.filename, 'r')
return self
def __next__(self):
try:
line = next(self.file)
except StopIteration as e:
self.file.close()
raise e
return line
def next(self):
return self.__next__()
@classmethod
def from_filepaths(cls, training_files, eager=False):
"""
Create POSTagger from list of file names
:param training_files: list of file names
:param eager: boolean: train while opening
:return: POStagger
"""
lazy_files = [POSTagger.LazyFile(fn) for fn in training_files]
return POSTagger(lazy_files, eager)
def __init__(self, data_io=(), eager=False):
self.corpus_parser = CorpusParser()
self.data_io = data_io
self.trained = False
if eager:
self.train()
self.trained = True
def train(self):
if not self.trained:
self.tags = set()
self.tag_combos = defaultdict(int)
self.tag_frequencies = defaultdict(int)
self.word_tag_combos = defaultdict(int)
for io in self.data_io:
for line in io:
for ngram in self.corpus_parser.parse(line):
self.write(ngram)
self.trained = True
def write(self, ngram):
"""
:param ngram:
"""
if ngram[0].tag == 'START':
self.tag_frequencies['START'] += 1
self.word_tag_combos['START/START'] += 1
self.tags.add(ngram[-1].tag)
self.tag_frequencies[ngram[-1].tag] += 1
combo = ngram[-1].word + '/' + ngram[-1].tag
self.word_tag_combos[combo] += 1
combo = ngram[0].tag + '/' + ngram[-1].tag
self.tag_combos[combo] += 1
def viterbi(self, sentence):
sentence1 = re.sub(r'([\.\?!])', r' \1', sentence)
parts = re.split(r'\s+', sentence1)
last_viterbi = {}
backpointers = ['START']
for tag in self.tags:
if tag == 'START':
continue
else:
probability = self.tag_probability('START', tag) \
* self.word_tag_probability(parts[0], tag)
if probability > 0:
last_viterbi[tag] = probability
if len(last_viterbi) > 0:
backpointer = max(last_viterbi,
key=(lambda key: last_viterbi[key]))
else:
backpointer = max(self.tag_frequencies,
key=(lambda key: self.tag_frequencies[key]))
backpointers.append(backpointer)
for part in parts[1:]:
viterbi = {}
for tag in self.tags:
if tag == 'START':
continue
if len(last_viterbi) == 0:
break
best_tag = max(last_viterbi,
key=(lambda prev_tag: last_viterbi[prev_tag] *
self.tag_probability(prev_tag, tag) *
self.word_tag_probability(part, tag)))
probability = last_viterbi[best_tag] * \
self.tag_probability(best_tag, tag) * \
self.word_tag_probability(part, tag)
if probability > 0:
viterbi[tag] = probability
last_viterbi = viterbi
if len(last_viterbi) > 0:
backpointer = max(last_viterbi,
key=(lambda key: last_viterbi[key]))
else:
backpointer = max(self.tag_frequencies,
key=(lambda key: self.tag_frequencies[key]))
backpointers.append(backpointer)
return backpointers
def tag_probability(self, previous_tag, current_tag):
"""Maximum likelihood estimate
count(previous_tag, current_tag) / count(previous_tag)"""
denom = self.tag_frequencies[previous_tag]
if denom == 0:
return 0
else:
return self.tag_combos[previous_tag + '/' + current_tag] / float(denom)
def word_tag_probability(self, word, tag):
"""Maximum Likelihood estimate
count (word and tag) / count(tag)"""
denom = self.tag_frequencies[tag]
if denom == 0:
return 0
else:
return self.word_tag_combos[word + '/' + tag] / float(denom)
def probability_of_word_tag(self, words, tags):
if len(words) != len(tags):
raise ValueError('The word and tags must be the same length!')
length = len(words)
probability = 1.0
for i in range(1, length):
probability *= self.tag_probability(tags[i - 1], tags[i]) * \
self.word_tag_probability(words[i], tags[i])
return probability
class POSTagger:
def __init__(self, data_io):
self.corpus_parser = CorpusParser()
self.data_io = data_io
self.trained = False
def train(self):
if not self.trained:
self.tags = set(['Start'])
self.tag_combos = defaultdict(lambda: 0, {})
self.tag_frequencies = defaultdict(lambda: 0, {})
self.word_tag_combos = defaultdict(lambda: 0, {})
for io in self.data_io:
for line in io.read_lines():
for ngram in self.corpus_parser.parse(line):
write(ngram)
self.trained = True
def write(self, ngram):
if ngram[0].tag == 'START':
self.tag_frequencies['START'] += 1
self.word_tag_combos['START/START'] += 1
self.tags.append(ngram[-1])
self.tag_frequencies[ngram[-1].tag] += 1
self.word_tag_combos['/'.join([ngram[-1].word, ngram[-1].tag])] += 1
self.tag_combos["/".join([ngram[0].tag, ngram[-1].tag])] += 1
def tag_probability(previous_tag, current_tag):
denom = self.tag_frequencies[previous_tag]
if denom == 0:
return 0.0
else:
return self.tag_combos['/'.join(previous_tag, current_tag)] / float(denom)
def word_tag_probability(word, tag):
denom = self.tag_frequencies[tag]
if denom == 0:
return 0.0
else:
self.word_tag_combos["/".join(word, tag)] / float(denom)
def probability_of_word_tag(word_sequence, tag_sequence):
if len(word_sequence) != len(tag_sequence):
raise Exception('The word and tags must be the same length...')
length = len(word_sequence)
probability = 1.0
for i in range(1, length):
probability *= (
tag_probability(tag_sequence[i - 1], tag_sequence[i]) *
word_tag_probability(word_sequence[i], tag_sequence[i])
)
return probability
def viterbi(self, sentence):
parts = re.sub(r"([\.\?!])", r" \1", sentence)
last_viterbi = {}
backpointers = ['START']
for tag in self.tags:
if tag == 'START':
next()
else:
probability = tag_probability('START', tag) * \
word_tag_probability(parts[0], tag)
if probability > 0:
last_viterbi[tag] = probability
backpointers.append(
max(v for v in last_viterbi.values()) or
max(v for c in self.tag_frequencies.values())
)
for part in parts[1:]:
viterbi = {}
for tag in self.tags:
if tag == 'START':
next()
if last_viterbi:
break
best_previous = max(
for ((prev_tag, probability) in last_viterbi.iteritems()):
probability * \
tag_probability(prev_tag, tag) * \
word_tag_probability(part,tag)
)
best_tag = best_previous[0]
probability = last_viterbi[best_tag] * \
tag_probability(best_tag, tag) * \
word_tag_probability(part, tag)
if probability > 0:
viterbi[tag] = probability
last_viterbi = viterbi
backpointers << (
max(v for v in last_viterbi.itervalues()) or
max(v for v in self.tag_frequencies.itervalues())
)
return backpointers