def save_stems(self):
if self.draft or not HAS_LIBSTEMMER:
return
try:
stemmer = Stemmer(self.language.iso639_1)
except RuntimeError:
return
self.stems.all().delete()
r = re.compile('\w{4,32}', re.UNICODE)
words = r.findall(self.body)
num_words = float(len(words))
stemmed_words = {}
for word in words:
stem_value = stemmer.stem(word)
stemmed_words.setdefault(stem_value, 0)
stemmed_words[stem_value] += 1
for stem, value in stemmed_words.iteritems():
stem, created = Stem.objects.get_or_create(value=stem)
self.stems.create(stem=stem, value=value/num_words)
self.find_related()
class TP:
"""Text Processing, TP class
***NOTE: This is a simple, beta tool and low-performance now***
HOW-TO:
1. instantiate
2. use .addDoc(filename) first
3. analyze()
4. showStat()
This class has several main functions:
- removing stop words
- stemming/lemmatizing
- calculating TF-IDF
"""
def __init__(self):
# establish stopword set
self.stopword_set = set()
# for sotring added file data
self.doc_wordlist = {}
# doc_topic_dict = {docname: topic_ist, ...}
self.doc_topic_dict = {}
# for TF-IDF (term frequency - inverse document frequency)
# tfidf_dict/tf_dict = {filename : {feature : TF, ...}, ...}
# idf_dict = {word : IDF, ...}
self.tf_dict = {}
self.idf_dict = {}
self.tfidf_dict = {}
self.doc_with_word_counter = {}
self.docs_total = 0
# for cosine similarity
# it looks like:
# {
# 'docA': {'docA': xxx, 'docB': xxx, ...},
# 'docB': {'docA': xxx, 'docB': xxx, ...},
# ...
# }
self.cos_dict = {}
# for normalize word (regex)
self.enableRegex = True
# ask if user want to enable regex filter
self.restr = r'[a-zA-Z\-][a-zA-Z\-]*'
req = raw_input("Enable regex filter ? (default: r'[a-zA-Z\-][a-zA-Z\-]*'. enter 'no' to disable it): ")
if req == 'no':
print('Disable regex filter')
self.enableRegex = False
else:
self.enableRegex = True
# set stopword list
self.enableStopword = True
# ask if enable stopword filter
spq = raw_input("Enable stopword filter ? ( 'no' to disable ): ")
if spq == 'no':
print('Disable stopword filter')
self.enableStopword = False
else:
self.enableStopword = True
if self.enableStopword:
stopwdf = raw_input("Please input stopword list path (keep empty for default 'stopwords.txt'): ")
if stopwdf:
self.setStopwdList(stopwdf)
else:
self.setStopwdList('stopwords.txt')
# ask if user want to use stemmer
self.enableStemmer = True
smq = raw_input('Enable stemmer ? ( "no" to disable ): ')
if smq == 'no':
print('Disable stemmer')
self.enableStemmer = False
else:
self.enableStemmer = True
# setup stemmer
if self.enableStemmer:
self.stemmer = Stemmer()
def setStopwdList(self, filename):
try:
with open(filename, 'r') as f_swlist:
self.stopword_set = set(f_swlist.read().splitlines())
print "[INFO] reading stopwords list done."
except IOError:
sys.stderr.write("[Error] failed to open stopwords list\n")
sys.stderr.write("[Warning] Assign stopword list failed. Please try setStopwdList(filename) again.\n")
### output methods ###
def showStat(self, docname=None):
""" Show TF-IDF info about docs. If docname is now given, show all docs.
"""
if len(self.tfidf_dict) <= 0:
print "[Error] There is no data in corpus. Please use addDoc() and autoTfidf() to conduct an analysis."
return 1
if docname:
self.printTFIDF(docname)
else:
for dname in self.tfidf_dict:
self.printTFIDF(dname)
def printTFIDF(self, docname):
""" print formatted TF and TFIDF info
"""
d_tfidf = self.tfidf_dict[docname]
d_tf = self.tf_dict[docname]
print 'TFIDF info. of %s\n' % docname
print 'Word --> TF\tTF-IDF'
print '-------------------\n'
for word in d_tfidf:
if word in d_tf:
print '{wd:<16s} --> {tf:e}\t{idf:e}'.format(wd=word, tf=d_tf[word], idf=d_tfidf[word])
else:
print '{wd:<16s} --> {tf:e}\t{idf:e}'.format(wd=word, tf='KEY ERROR', idf=d_tfidf[word])
print '-------------------\n'
def printIDF(self):
""" print IDF information
"""
print 'Word --> IDF'
for word in self.idf_dict:
print '{wd:<16s} --> {idf}'.format(wd=word, idf=self.idf_dict[word])
def exportTfidf(self, limit=0, filename=None):
"""
Now this function can only output tfidf_dict as JSON.
limit is the number of data you want to output.
"""
# if filename is not specified, use date-time instead.
if not filename:
filename = time.strftime('%h-%d-%Y-%I-%M-%p')+'_TFIDF_dict.json'
# export whole tfidf_dict
with open(filename, 'w') as fout:
if (limit == 0):
out_dict = self.tfidf_dict
else:
out_dict = {}
# counter
cnter = 0
for (key, val) in self.tfidf_dict.items():
out_dict[key] = val
cnter+=1
if cnter >= limit:
break
# translate python dict into json
outjson = json.dumps(out_dict, sort_keys=True, indent=4)
fout.write(outjson)
print('[Info] TFIDF_dict has been exported as file {fn:s}'.format(fn=filename))
### word processors ###
def testStopword(self, word):
""" Evaluate one word and figure out whether it is a stopword
from self.stopwordlist.
If so, return true.
Otherwise return false.
"""
if word in self.stopword_set:
return True
return False
def stemming(self, word, stway=None):
""" With given word and specified stemming algorithm,
return it's stemming result.
If no algorithm is specified, use XXX as default.
"""
return self.stemmer.stemming(word)
### TF-IDF calculator ###
def analyze(self):
""" Automatically run tf(), idf() and tfidf()
"""
print "[INFO] starting auto TF-IDF calculator"
# record start time
start_time = time.time()
self.tf()
self.idf()
self.tfidf()
# record end time
end_time = time.time()
print "[INFO] Finished"
print "[INFO] Use showStat() to show the result"
print "[Info] Total time of execution: {timestr:s}".format(timestr=str(end_time-start_time))
def tfidf(self):
""" calculate TF-IDF
"""
print "[INFO] calculating TF-IDF..."
for doc_name in self.tf_dict:
tmp_dict = {}
doc_wl = self.tf_dict[doc_name]
for word in doc_wl:
# TF-IDF = TF * IDF
tmp_dict[word] = doc_wl[word] * self.idf_dict[word]
# store result to tfidf_dict
# tfidf_dict looks like {filename : {word1 : IDF, word2 : IDF, ...}, ...}
self.tfidf_dict[doc_name] = tmp_dict
def tf(self):
""" calculate TF of added docs and store them to self.tf_dict
"""
print "[INFO] calculating TF..."
# iterate whole doc_wordlist
if len(self.doc_wordlist) > 0:
for doc_name in self.doc_wordlist:
print "[Info] tf: " + str(doc_name)
# make a container
word_tf_dict = {}
# retrieve word list of from doc_wordlist and remove the key in dict
wl = self.doc_wordlist[doc_name]
word_num = len(wl)
# calculate term frequency (within a file)
for word in wl:
# count the number of word within a file and store it to word_tf_dict temporarily
# get previous record and pile up
be = word_tf_dict.get(word, 0.0)
word_tf_dict[word] = be + 1.0
# reserve words for IDF
if not word in self.idf_dict:
self.idf_dict[word] = 0.0
#print "[Debug] tf: TF result: " + doc_name + " " + str(word_tf_dict)
# normalize
word_tf_dict = dict(map(lambda (k,v) : (k,v/word_num), word_tf_dict.iteritems()))
# save result
self.tf_dict[doc_name] = word_tf_dict
#print "[Debug] result: " + doc_name + " " + str(self.tf_dict[doc_name])
else:
sys.stderr.write("[Error] tf: there is no file in queue\n")
sys.stderr.write("[Error] tf: please use addDoc first\n")
def idf(self):
""" calculate current idf with all docs have been added
"""
print "[INFO] calculating IDF..."
# log(total number of documents)
log_doc_total = math.log(self.docs_total, 10)
# use self.idf_dict
# retrieve word from idf_dict
for word in self.idf_dict:
# initialize
self.idf_dict[word] = 0.0
### Attention !!! The code below make this program too inefficient.
### I have used self.word_counter instead to record the number of word when addDoc() was called
### ============================================================
# count the number of word through all docs
#for doc_name in self.tf_dict:
# if self.tf_dict[doc_name].has_key(word):
# self.idf_dict[word] += 1.0
### ============================================================
# calculate IDF
# log(word number)
### the line below is depreciated.
### log_tf = math.log(self.idf_dict[word], 10)
# log( the number of doc contains the word )
log_ndcw = math.log(self.doc_with_word_counter[word], 10)
# log(docs number) - log(word number)
self.idf_dict[word] = log_doc_total - log_ndcw
### file operating method ###
def addDoc(self, doc_name):
""" Read data from a doc, store it and return a word list of the content.
This function will also remove stopwords and do stemming.
"""
print('[Info] addDoc '+doc_name)
# for storing words
wd_list = []
# file reading mechanism has been adjusted
# specified input file format:
# Line 1 = question name
# Line 2 = topics
# Line 3... = answer content
try:
# open docs and read data
with open(doc_name, 'r') as f_in:
for i,line in enumerate(f_in):
# We ignore first line (question name)
if (i == 0):
pass
# How to deal with topics at second line ?
# Read topics into self.doc_topic_dict
if (i == 1):
self.doc_topic_dict[doc_name] = line.split(', ')
for word in line.split():
# if the length of word is zero, pass
if (len(word) == 0):
pass
# normalize the word. Get rid of punctuation which is not needed
if self.enableRegex:
matchedGrp = re.match(self.restr, word, re.M|re.I)
if matchedGrp:
word = matchedGrp.group(0)
else:
word = ''
# END if
# lowercast word
word = word.lower()
# remove stopwords here (if enabled)
if self.enableStopword and self.testStopword(word):
pass
else:
# stemming here
if self.enableStemmer:
# word = self.stemming(word)
pass
### These code below is used to calculate IDF later
### =========================================
# count the number of doc contains the word
# if current word has been in wd_list then ignore it to prevent counting the same word twice
if not word in wd_list:
pre_rc = self.doc_with_word_counter.get(word, 0.0)
self.doc_with_word_counter[word] = pre_rc + 1.0
### =========================================
# add word to word list
wd_list.append(word)
# END if
# END for words in line
# END for lines in file
# END with open file
# increase docs number
self.docs_total += 1
# store word list
self.doc_wordlist[doc_name] = wd_list
except IOError, e:
sys.stderr.write("[Error] addDoc failed.\n")
sys.stderr.write("[Error] error dump: {er:s}".format(er=str(e)))
return wd_list
def __init__(self):
# establish stopword set
self.stopword_set = set()
# for sotring added file data
self.doc_wordlist = {}
# doc_topic_dict = {docname: topic_ist, ...}
self.doc_topic_dict = {}
# for TF-IDF (term frequency - inverse document frequency)
# tfidf_dict/tf_dict = {filename : {feature : TF, ...}, ...}
# idf_dict = {word : IDF, ...}
self.tf_dict = {}
self.idf_dict = {}
self.tfidf_dict = {}
self.doc_with_word_counter = {}
self.docs_total = 0
# for cosine similarity
# it looks like:
# {
# 'docA': {'docA': xxx, 'docB': xxx, ...},
# 'docB': {'docA': xxx, 'docB': xxx, ...},
# ...
# }
self.cos_dict = {}
# for normalize word (regex)
self.enableRegex = True
# ask if user want to enable regex filter
self.restr = r'[a-zA-Z\-][a-zA-Z\-]*'
req = raw_input("Enable regex filter ? (default: r'[a-zA-Z\-][a-zA-Z\-]*'. enter 'no' to disable it): ")
if req == 'no':
print('Disable regex filter')
self.enableRegex = False
else:
self.enableRegex = True
# set stopword list
self.enableStopword = True
# ask if enable stopword filter
spq = raw_input("Enable stopword filter ? ( 'no' to disable ): ")
if spq == 'no':
print('Disable stopword filter')
self.enableStopword = False
else:
self.enableStopword = True
if self.enableStopword:
stopwdf = raw_input("Please input stopword list path (keep empty for default 'stopwords.txt'): ")
if stopwdf:
self.setStopwdList(stopwdf)
else:
self.setStopwdList('stopwords.txt')
# ask if user want to use stemmer
self.enableStemmer = True
smq = raw_input('Enable stemmer ? ( "no" to disable ): ')
if smq == 'no':
print('Disable stemmer')
self.enableStemmer = False
else:
self.enableStemmer = True
# setup stemmer
if self.enableStemmer:
self.stemmer = Stemmer()
