removed original file

crawler.py

@@ -5,35 +5,70 @@ Need a docstring.
 
 import argparse
 from utils.helpers import (UrlPool, WebPage, sanitise_url)
+from pprint import pprint
 
 def init_crawler(base_url=None):
     '''
     needs a docstring
     '''
     uncrawled_urls, crawled_urls = UrlPool(), UrlPool()
-    initial_page = WebPage(base_url)
+    initial_page = WebPage(url=base_url, base_url=base_url)
 
     try:
-        initial_urls = initial_page.run()
+        initial_page.run()
     except Exception as e:
         print(e)
 
+    initial_urls = initial_page.list_urls()
+    # ensure the base URL isn't crawled again
+    try:
+        initial_urls.remove(base_url)
+    except KeyError:
+        pass
+    # Add the base URL to the crawled pool
+    crawled_urls.add_to_pool(base_url)
+
     for url in initial_urls:
+        sanitised_url = sanitise_url(url=url)
+        if sanitised_url not in crawled_urls.pool:
+            uncrawled_urls.add_to_pool(sanitised_url)
+
+    return(uncrawled_urls, crawled_urls)
+
+
+def process_pool(base_url=None, uncrawled_urls=None, crawled_urls=None):
+    '''
+    Needs a docstring
+    '''
+    while uncrawled_urls.pool:
+        # pop url from pool
+        new_url = uncrawled_urls.remove_from_pool()
+        # create a WebPage object for the URL
+        current_page = WebPage(url=new_url, base_url=base_url)
         try:
-            uncrawled_urls.add_to_pool(url)
+            current_page.run()
+            _urls = current_page.list_urls()
+            crawled_urls.add_to_pool(new_url)
         except Exception as e:
             print(e)
 
-    print(uncrawled_urls.url_pool)
+        for url in _urls:
+            sanitised_url = sanitise_url(url=url)
+            if sanitised_url not in crawled_urls.pool:
+                uncrawled_urls.add_to_pool(url)
 
 
 def run(args=None):
     '''
     needs a docstring.
     '''
-    base_url = sanitise_url(args.url)
+    base_url = sanitise_url(args.url, base_url=True)
 
-    init_crawler(base_url)
+    uncrawled_urls, crawled_urls = init_crawler(base_url)
+    process_pool(base_url, uncrawled_urls, crawled_urls)
+
+    pprint(crawled_urls.pool)
+    print('{0} URLs crawled'.format(len(crawled_urls.pool)))
 
 
 if __name__ == '__main__':

scraper.py

@@ -1,88 +0,0 @@
-#!/usr/bin/env python
-
-import re
-import argparse
-import urllib.request
-from bs4 import BeautifulSoup
-
-class WebPage(object):
-
-    headers = {'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64; rv:61.0) Gecko/20100101 Firefox/61.0'}
-
-    def __init__(self, args):
-        self.url = args['url']
-
-
-    def get_source(self, args=None):
-        request = urllib.request.Request(self.url, headers=headers)
-        page = urllib.request.urlopen(request)
-        self.source = page.read()
-
-
-    def find_links(self, args=None, source=None):
-        soup = BeautifulSoup(self.source, 'html.parser')
-        links = soup.find_all('a')
-        hrefs = []
-
-        for link in links:
-            if link['href'].startswith('/'):
-                hrefs.append("".join([self.url, link['href']]))
-            else:
-                hrefs.append(link['href'])
-
-        return hrefs
-
-
-def run(args=None):
-    source = get_source(args)
-    urls = find_links(args, source)
-    local_urls = parse_urls(args, urls)
-
-    print(local_urls)
-
-def get_source(args=None):
-    url = args.url
-    useragent = 'Mozilla/5.0 (X11; Linux x86_64; rv:61.0) Gecko/20100101 Firefox/61.0'
-    headers = {'User-Agent': useragent}
-    request = urllib.request.Request(url, headers=headers)
-    page = urllib.request.urlopen(request)
-    source = page.read()
-
-    return source
-
-
-def find_links(args=None, source=None):
-    soup = BeautifulSoup(source, 'html.parser')
-    links = soup.find_all('a')
-    hrefs = []
-
-    for link in links:
-        if link['href'].startswith('/'):
-            hrefs.append("".join([args.url, link['href']]))
-        else:
-            hrefs.append(link['href'])
-
-    return hrefs
-
-
-def parse_urls(args=None, urls=None):
-    local_urls = []
-
-    for url in urls:
-        if url.startswith(args.url):
-            local_urls.append(url)
-
-
-    return local_urls
-
-
-if __name__ == "__main__":
-
-    parser = argparse.ArgumentParser(description='Recursive web scraper')
-    parser.add_argument("-u", "--url", required=True, help="Base url to scrape")
-    args = parser.parse_args()
-
-    if not args.url.startswith('http'):
-        raise SystemExit('URL must start with a protocol (http(s)).')
-
-    run(args)

utils/helpers.py

@@ -14,22 +14,29 @@ class UrlPool(object):
     '''
 
     def __init__(self):
-        self.url_pool = set()
+        self.pool = set()
 
     def check_duplicate(self, new_url):
         '''
         Checks if a URL exists in the current pool.
         '''
-        if new_url in self.url_pool:
+        if new_url in self.pool:
             return True
         else:
             return False
 
-    def remove_from_pool(self, url):
-        self.url_pool.remove(url)
+    def remove_from_pool(self):
+        '''
+        Remove a URL from the pool and return it to be crawled.
+        '''
+        return(self.pool.pop())
 
     def add_to_pool(self, url):
-        self.url_pool.add(url)
+        self.pool.add(url)
+
+    def list_pool(self):
+        pool = self.pool
+        return pool
 
 
 class WebPage(object):
@@ -40,8 +47,9 @@ class WebPage(object):
 
     headers = {'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64; rv:61.0) Gecko/20100101 Firefox/61.0'}
 
-    def __init__(self, url):
+    def __init__(self, url=None, base_url=None):
         self.url = url
+        self.base_url = base_url
 
 
     def get_source(self):
@@ -50,7 +58,7 @@ class WebPage(object):
         '''
 
         request = urllib.request.Request(self.url, headers=self.headers)
-        page = urllib.request.urlopen(request)
+        page = urllib.request.urlopen(request, timeout=5)
         self.source = page.read()
 
 
@@ -62,7 +70,7 @@ class WebPage(object):
         hrefs = set()
 
         soup = BeautifulSoup(self.source, 'html.parser')
-        links = soup.find_all('a')
+        links = soup.find_all('a', href=True)
 
         for link in links:
             if link['href'].startswith('/'):
@@ -78,11 +86,20 @@ class WebPage(object):
         Iterate through the list of discovered URLs and add them to the
         pool if they start with the base URL.
         '''
-
         self.urls_to_crawl = set()
+
         for url in self.discovered_hrefs:
             if url.startswith(self.url):
-                self.urls_to_crawl.add(url)
+                sanitised_url = sanitise_url(url=url)
+                self.urls_to_crawl.add(sanitised_url)
+
+
+    def list_urls(self):
+        '''
+        Returns the contents of the
+        '''
+
+        return self.urls_to_crawl
 
 
     def run(self):
@@ -101,24 +118,32 @@ class WebPage(object):
         except Exception as e:
             print(e)
 
-        return self.urls_to_crawl
 
-
-def sanitise_url(url):
+def sanitise_url(url, base_url=False):
     '''
-    Attempt to standardise the base url to ensure it can be prepended to
-    relative URLs. If no scheme provided then we default to http as any
-    sane https-only site should 301 redirect http > https.
+    If `base_url` is True, we attempt to standardise `url` to ensure it can be
+    prepended to relative URLs. If no scheme has been provided then we default
+    to http as any sane https-only site should 301 redirect http > https.
 
-    Returns a corrected base URL as a string.
+    If `base_url` is False, we sanitise URLs to strip queries and fragments (we
+    don't want to scrape in-page anchors etc).
+
+    Returns a sanitised URL as a string.
     '''
     default_proto = 'http'
     delim = '://'
 
     split_url = urlsplit(url)
-    if split_url.scheme and split_url.scheme.startswith('http'):
-        base_url = "".join([split_url.scheme, delim, split_url.netloc])
-    elif (split_url.path and not split_url.scheme and not split_url.netloc):
-        base_url = "".join([default_proto, delim, split_url.path])
 
-    return base_url
+    if base_url:
+        # This will sanitise the initial url for the initial page crawl.
+        if split_url.scheme and split_url.scheme.startswith('http'):
+            sanitised_url = "".join([split_url.scheme, delim, split_url.netloc])
+        elif (split_url.path and not split_url.scheme and not split_url.netloc):
+            sanitised_url = "".join([default_proto, delim, split_url.path])
+    else:
+        # Sanitise discovered URLs. We already expect them in the format
+        # protocol://base_url/path
+        sanitised_url = "".join([split_url.scheme, delim, split_url.netloc, split_url.path])
+
+    return sanitised_url