Search_Engine/indexer.py
2022-05-13 16:42:33 -07:00

235 lines
7.4 KiB
Python

#We have to import the files
#Split the indexer into 4 parts
#Alphanumeric sequences into the dataset
#Stemming
#Text in bold, headings and other titles should be treated as more important
#Posting structure > tf-idf score. Name/id the token was found in . So hashmap.
#We need shelves to hold the data.
#Posting ---> Source of file, tf-idf score. #for now we will only use these two, as we get more complex posting will be change accordingly
#Data input
import json
import os
import shelve
from bs4 import BeautifulSoup
from time import perf_counter
import time
import threading
import pickle
#Data process
from nltk.tokenize import word_tokenize
from nltk.stem import PorterStemmer
from sklearn.feature_extraction.text import TfidfVectorizer
import pandas as pd
import numpy as np
import re
#Logging postings
from posting import Posting
from worker import Worker
class Indexer():
def __init__(self,restart,trimming):
#Config stuffs
self.path = "D:/Visual Studio Workspace/CS121/assignment3/data/DEV/"
self.restart = restart
self.trimming = trimming
self.stemmer = PorterStemmer()
self.id = list()
# Creates a pickle file that is a list of urls where the index of the url is the id that the posting refers to.
p = os.path.dirname(os.path.abspath(__file__))
my_filename = os.path.join(p, "urlID.pkl")
if os.path.exists(my_filename):
os.remove(my_filename)
# Creates file and closes it
self.f = open(my_filename, "wb")
pickle.dump(id, self.f)
self.f.close()
# Opens for reading for the entire duration of indexer for worker to use
self.f = open(my_filename, "rb+")
#Shelves for index
#https://www3.nd.edu/~busiforc/handouts/cryptography/letterfrequencies.html
#https://www.irishtimes.com/news/science/how-many-numbers-begin-with-a-1-more-than-30-per-cent-1.4162466
#According to this will be how we split things
#Save #1 = ABCD + (1) ~ 18.3% of words
#Save #2 = EFGHIJK + (2-3)~ 27.1% of words
#Save #3 = LMNOPQ + (4-7) ~ 25.4% of words
#Save #4 = RSTUVWXYZ + (8-9)~ 29.2% of words
#Save #5 = Special characters
if os.path.exists("save_1.shelve") and restart:
os.remove("save_1.shelve")
if os.path.exists("save_2.shelve") and restart:
os.remove("save_2.shelve")
if os.path.exists("save_3.shelve") and restart:
os.remove("save_3.shelve")
if os.path.exists("save_4.shelve") and restart:
os.remove("save_4.shelve")
if os.path.exists("save_5.shelve") and restart:
os.remove("save_5.shelve")
self.save_1 = shelve.open("save_1.shelve")
self.save_1_lock = threading.Lock()
self.save_2 = shelve.open("save_2.shelve")
self.save_2_lock = threading.Lock()
self.save_3 = shelve.open("save_3.shelve")
self.save_3_lock = threading.Lock()
self.save_4 = shelve.open("save_4.shelve")
self.save_4_lock = threading.Lock()
self.save_5 = shelve.open("save_5.shelve")
self.save_5_lock = threading.Lock()
print(len(list(self.save_1.keys())))
print(len(list(self.save_2.keys())))
print(len(list(self.save_3.keys())))
print(len(list(self.save_4.keys())))
print(len(list(self.save_5.keys())))
def get_url_id(self, url):
return self.id.index(url)
def save_index(self,word,posting):
cur_save = self.get_save_file(word)
lock = self.get_save_lock(word)
lock.acquire()
shelve_list = list()
try:
shelve_list = cur_save[word]
shelve_list.append(posting)
tic = perf_counter()
# Sort by url id to help with query search
shelve_list.sort(key=lambda x: x.url)
# shelve_list.sort(key=lambda x: x.tf_idf, reverse = True)
toc = perf_counter()
if toc - tic > 1 :
print("Took " + str(toc - tic) + "seconds to sort shelve list !")
cur_save.sync()
lock.release()
except:
shelve_list.append(posting)
cur_save[word] = shelve_list
cur_save.sync()
lock.release()
def get_save_file(self,word):
#return the correct save depending on the starting letter of word
word_lower = word.lower()
if re.match(r"^[a-d0-1].*",word_lower):
return self.save_1
elif re.match(r"^[e-k2-3].*",word_lower):
return self.save_2
elif re.match(r"^[l-q4-7].*",word_lower):
return self.save_3
elif re.match(r"^[r-z8-9].*",word_lower):
return self.save_4
else:
print(word)
print("You have somehow went beyond the magic")
return self.save_5
def get_save_lock(self,word):
word_lower = word.lower()
if re.match(r"^[a-d0-1].*",word_lower):
return self.save_1_lock
elif re.match(r"^[e-k2-3].*",word_lower):
return self.save_2_lock
elif re.match(r"^[l-q4-7].*",word_lower):
return self.save_3_lock
elif re.match(r"^[r-z8-9].*",word_lower):
return self.save_4_lock
else:
print(word)
print("You have somehow went beyond the magic")
return self.save_5_lock.acquire()
# I have a test file (mytest.py) with pandas but couldn't figure out how to grab just a single cell.
# so I came up with this, if anyone knows how to get a single cell and can explain it to
# me I would love to know, as I think that method might be quicker, maybe, idk it like
# 4am
# https://stackoverflow.com/questions/34449127/sklearn-tfidf-transformer-how-to-get-tf-idf-values-of-given-words-in-documen
# removed parameter "word" since it wasn't used
# TODO: Add important words scaling
def get_tf_idf(self, words):
# words = [whole text] one element list
# return the score
try:
tfidf = TfidfVectorizer(ngram_range=(1,3)) # ngram_range is range of n-values for different n-grams to be extracted (1,3) gets unigrams, bigrams, trigrams
tfidf_matrix = tfidf.fit_transform(words) # fit trains the model, transform creates matrix
df = pd.DataFrame(tfidf_matrix.toarray(), columns = tfidf.get_feature_names_out()) # store value of matrix to associated word/n-gram
#return(df.iloc[0][''.join(word)]) #used for finding single word in dataset
data = df.to_dict() # transform dataframe to dict *could be expensive the larger the data gets, tested on ~1000 word doc and took 0.002 secs to run
return data # returns the dict of words/n-grams with tf-idf
#print(df) # debugging
except:
print("Error in tf_idf!")
return
def get_data(self):
num_threads = 8
threads = list()
for directory in os.listdir(self.path):
for file in os.listdir(self.path + "/" + directory + "/"):
#Actual files here
#JSON["url"] = url of crawled page, ignore fragments
#JSON["content"] = actual HTML
#JSON["encoding"] = ENCODING
index = 0
while True:
file_path = self.path + "" + directory + "/"+file
# Add url to id here so that there isn't any problems when worker is multi-threaded
load = open(file_path)
data = json.load(load)
if data["url"] not in self.id:
self.id.append(data["url"])
if len(threads) < num_threads:
thread = Worker(self,file_path)
threads.append(thread)
thread.start()
break
else:
if not threads[index].is_alive():
threads[index] = Worker(self,file_path)
threads[index].start()
break
else:
index = index + 1
if(index >= num_threads):
index = 0
time.sleep(.1)
pickle.dump(self.id, self.f)
# should I self.f.close() here?
#Found 55770 documents
#
#getting important tokens
def main():
indexer = Indexer(True,0)
indexer.get_data()
if __name__ == "__main__":
main()