Search_Engine/worker_weight.py
2022-05-27 09:53:25 -07:00

110 lines
2.8 KiB
Python

from threading import Thread
import json
import os
from bs4 import BeautifulSoup
import re
import math
import time
#Data process
from nltk.tokenize import word_tokenize
from nltk.stem import PorterStemmer
from posting import Posting
import sys
class Node():
index_value = ''
postings = list()
class Index():
length = 0
index = list()
class Worker_Weight(Thread):
def __init__(self,worker_id,indexer):
self.indexer = indexer
self.stemmer = PorterStemmer()
self.worker_id = worker_id
self.num_partial = 0
self.weight = dict()
merged_index_index = open("merged_index.index" ,'r')
self.merged_index = open("merged_index.full",'r')
merged_index_index.seek(0,0)
json_value = merged_index_index.readline()
data = json.loads(json_value)
self.index_index = dict(data['index'])
super().__init__(daemon=True)
def dump(self):
with open("docs"+str(self.worker_id)+".weight",'w') as f:
f.write(json.dumps(self.weight))
def run(self):
while True:
target = self.indexer.get_next_file()
if not target:
self.dump()
print("Worker " + str(self.worker_id) + " died")
break
print("Worker " + str(self.worker_id) + " weighting " + target)
file_load = open(target)
data = json.load(file_load)
soup = BeautifulSoup(data["content"],features="lxml")
url = data['url']
doc_id = target[target.rfind('/')+1:-5]
# Gets a cleaner version text comparative to soup.get_text()
clean_text = ' '.join(soup.stripped_strings)
# Looks for large white space, tabbed space, and other forms of spacing and removes it
# Regex expression matches for space characters excluding a single space or words
clean_text = re.sub(r'\s[^ \w]', '', clean_text)
# Tokenizes text and joins it back into an entire string. Make sure it is an entire string is essential for get_tf_idf to work as intended
clean_text = " ".join([i for i in clean_text.split() if i != "" and re.fullmatch('[A-Za-z0-9]+', i)])
# Stems tokenized text
clean_text = " ".join([self.stemmer.stem(i) for i in clean_text.split()])
# Put clean_text as an element in a list because get_tf_idf workers properly with single element lists
tokens = word_tokenize(clean_text)
total = 0
counter = dict()
#We calculating tf_raw, and positionals here
for i in range(len(tokens)):
word = tokens[i]
if word in counter:
counter[word]= counter[word] + 1
else:
counter[word] = 1
doc_length = len(tokens)
for index in tokens:
to_seek = self.index_index[index]
self.merged_index.seek(to_seek,0)
json_value = self.merged_index.readline()
data = json.loads(json_value)
df = len(data['postings'])
tf = counter[index]/doc_length
idf = math.log(self.indexer.num_doc/df)
tf_idf = tf*idf
total = total + tf_idf*tf_idf
self.weight[doc_id] = math.sqrt(total)