webcrawler/spacetime-crawler4py-master/scraper.py
2022-04-18 02:25:03 -07:00

125 lines
4.6 KiB
Python

from operator import truediv
import re
from urllib.parse import urlparse
from urllib.parse import urljoin
from bs4 import BeautifulSoup
def scraper(url, resp):
links = extract_next_links(url, resp)
links_valid = list()
valid_links = open("valid_links.txt",'a')
invalid_links = open("invalid_links.txt",'a')
for link in links:
if is_valid(link):
links_valid.append(link)
valid_links.write(link + "\n")
else:
invalid_links.write("From: " + url + "\n")
invalid_links.write(link + "\n")
return links_valid
def extract_next_links(url, resp):
# Implementation required.
# url: the URL that was used to get the page
# resp.url: the actual url of the page
# resp.status: the status code returned by the server. 200 is OK, you got the page. Other numbers mean that there was some kind of problem.
# resp.error: when status is not 200, you can check the error here, if needed.
# resp.raw_response: this is where the page actually is. More specifically, the raw_response has two parts:
# resp.raw_response.url: the url, again
# resp.raw_response.content: the content of the page!
# Return a list with the hyperlinks (as strings) scrapped from resp.raw_response.content
pages = list()
if resp.status == 200:
#do stuff
soup = BeautifulSoup(resp.raw_response.content)
tempFile = open("test6.txt", 'a')
#Getting all the links, href = true means at least theres a href value, dont know what it is yet
for link in soup.find_all('a', href=True):
#There is a lot of relative paths stuff here gotta add them
href_link = link.get('href')
#Relative path
##Suprisingly index fail safe
#some <a href> give //thenlink.com...
if href_link.startswith("//"):
href_link = href_link[2:]
#Relative path fixing
if(href_link.startswith("/")):
href_link = urljoin(url,href_link)
#skipping query with specific actions which mutate the websites and cause a trap
if "do=" in href_link:
continue
tempFile.write(href_link + "\n")
#Adding to the boi wonder pages
pages.append(href_link)
else:
print("Page error !")
return pages
# hopefuly fixes some loop traps and repeating (looping) directories
# the amount of repeated subdirectories allowed can be changed
# https://subscription.packtpub.com/book/big-data-and-business-intelligence/9781782164364/1/ch01lvl1sec11/crawling-your-first-website
# https://www.searchenginejournal.com/crawler-traps-causes-solutions-prevention/305781/
def is_a_loop_trap(url):
word_dict = {}
parsed = urlparse(url)
url_path = str(parsed.path)
word_list = url_path.split('/')
for word in word_list:
if word in word_dict:
word_dict[word] += 1
if word_dict[word] == 3:
return True
else:
word_dict[word] = 1
return False
#*.ics.uci.edu/*
#*.cs.uci.edu/*
#*.informatics.uci.edu/*
#*.stat.uci.edu/*
#today.uci.edu/department/information_computer_sciences/*
def is_valid(url):
# Decide whether to crawl this url or not.
# If you decide to crawl it, return True; otherwise return False.
# There are already some conditions that return False.
try:
#Gotta check if they are in the domain
parsed = urlparse(url)
if parsed.scheme not in set(["http", "https"]):
return False
elif re.match(
r".*\.(css|js|bmp|gif|jpe?g|ico"
+ r"|png|tiff?|mid|mp2|mp3|mp4"
+ r"|wav|avi|mov|mpeg|ram|m4v|mkv|ogg|ogv|pdf"
+ r"|ps|eps|tex|ppt|pptx|doc|docx|xls|xlsx|names"
+ r"|data|dat|exe|bz2|tar|msi|bin|7z|psd|dmg|iso"
+ r"|epub|dll|cnf|tgz|sha1"
+ r"|thmx|mso|arff|rtf|jar|csv"
+ r"|rm|smil|wmv|swf|wma|zip|rar|gz)$",parsed.path.lower()):
return False
elif not re.match(
r".*ics.uci.edu/.*"
+ r"|.*cs.uci.edu/.*"
+ r"|.*informatics.uci.edu/.*"
+ r"|.*stat.uci.edu/.*"
+ r"|today.uci.edu/department/information_computer_sciences/.*",url):
return False
elif parsed.fragment:
return False
elif is_a_loop_trap(url):
return False
else:
return True
except TypeError:
print ("TypeError for ", parsed)
raise