Search_Engine/indexer.py

116 lines
3.4 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
#Data process
from nltk.tokenize import word_tokenize
import re
class Indexer():
def __init__(self,restart,trimming):
#Config stuffs
self.path = "data/DEV/"
self.restart = restart
self.trimming = trimming
#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 = Numbers ???
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")
self.save_1 = shelve.open("save_1.shelve")
self.save_2 = shelve.open("save_2.shelve")
self.save_3 = shelve.open("save_3.shelve")
self.save_4 = shelve.open("save_4.shelve")
def save_index(self,word,posting):
wordhash = hash(word) ##Honestly do not know why hashing is even needed, might cause more problems
cur_save = get_save(word)
shelve_list = list()
if wordhash not in cur_save:
shelve_list.append(posting)
cur_save[wordhash] = shelve_list
cur_save.sync()
else:
shelve_list = cur_save[wordhash]
shelve_list.append(posting)
shelve_list.sort(key=lambda x: x.tf_idf, reverse = True)
cur_save.sync()
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-d1-1].*",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("You have somehow went beyond the magic")
return None
def get_data(self):
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
print(file)
file_load = open(self.path + "/" + directory + "/"+file)
data = json.load(file_load)
soup = BeautifulSoup(data["content"],from_encoding=data["encoding"])
words = word_tokenize(soup.get_text())
for word in words:
if word is not "" and word.isalnum():
print(word)
exit(1)
def main():
indexer = Indexer(True,0)
indexer.get_data()
if __name__ == "__main__":
main()