1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
# /usr/bin/env python
# -*- coding:utf-8 -*-
# Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserved
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""
The script fetch and preprocess movie_reviews data set that provided by NLTK
TODO(yuyang18): Complete dataset.
"""
import collections
from itertools import chain
import nltk
from nltk.corpus import movie_reviews
import common
__all__ = ['train', 'test', 'get_word_dict']
NUM_TRAINING_INSTANCES = 1600
NUM_TOTAL_INSTANCES = 2000
def download_data_if_not_yet():
"""
Download the data set, if the data set is not download.
"""
try:
# make sure that nltk can find the data
if common.DATA_HOME not in nltk.data.path:
nltk.data.path.append(common.DATA_HOME)
movie_reviews.categories()
except LookupError:
print "Downloading movie_reviews data set, please wait....."
nltk.download('movie_reviews', download_dir=common.DATA_HOME)
print "Download data set success....."
print "Path is " + nltk.data.find('corpora/movie_reviews').path
def get_word_dict():
"""
Sorted the words by the frequency of words which occur in sample
:return:
words_freq_sorted
"""
words_freq_sorted = list()
word_freq_dict = collections.defaultdict(int)
download_data_if_not_yet()
for category in movie_reviews.categories():
for field in movie_reviews.fileids(category):
for words in movie_reviews.words(field):
word_freq_dict[words] += 1
words_sort_list = word_freq_dict.items()
words_sort_list.sort(cmp=lambda a, b: b[1] - a[1])
for index, word in enumerate(words_sort_list):
words_freq_sorted.append((word[0], index))
return words_freq_sorted
def sort_files():
"""
Sorted the sample for cross reading the sample
:return:
files_list
"""
files_list = list()
neg_file_list = movie_reviews.fileids('neg')
pos_file_list = movie_reviews.fileids('pos')
files_list = list(chain.from_iterable(zip(neg_file_list, pos_file_list)))
return files_list
def load_sentiment_data():
"""
Load the data set
:return:
data_set
"""
data_set = list()
download_data_if_not_yet()
words_ids = dict(get_word_dict())
for sample_file in sort_files():
words_list = list()
category = 0 if 'neg' in sample_file else 1
for word in movie_reviews.words(sample_file):
words_list.append(words_ids[word.lower()])
data_set.append((words_list, category))
return data_set
def reader_creator(data):
"""
Reader creator, generate an iterator for data set
:param data:
train data set or test data set
"""
for each in data:
yield each[0], each[1]
def train():
"""
Default train set reader creator
"""
data_set = load_sentiment_data()
return reader_creator(data_set[0:NUM_TRAINING_INSTANCES])
def test():
"""
Default test set reader creator
"""
data_set = load_sentiment_data()
return reader_creator(data_set[NUM_TRAINING_INSTANCES:])