Handle more http edge cases in scraper
Handle more http edge cases in scraper


Former-commit-id: 994d782d8883843a55bf2558f8e6a6c9ffbcebde

file:a/scrape.py -> file:b/scrape.py
--- a/scrape.py
+++ b/scrape.py
@@ -7,6 +7,61 @@
 from urlparse import urljoin
 import time
 import os
+import mimetypes
+import re
+import urllib
+import urlparse
+
+def canonurl(url):
+    r"""Return the canonical, ASCII-encoded form of a UTF-8 encoded URL, or ''
+    if the URL looks invalid.
+    >>> canonurl('\xe2\x9e\xa1.ws')  # tinyarro.ws
+    'http://xn--hgi.ws/'
+    """
+    # strip spaces at the ends and ensure it's prefixed with 'scheme://'
+    url = url.strip()
+    if not url:
+        return ''
+    if not urlparse.urlsplit(url).scheme:
+        url = 'http://' + url
+
+    # turn it into Unicode
+    #try:
+    #    url = unicode(url, 'utf-8')
+    #except UnicodeDecodeError:
+    #    return ''  # bad UTF-8 chars in URL
+
+    # parse the URL into its components
+    parsed = urlparse.urlsplit(url)
+    scheme, netloc, path, query, fragment = parsed
+
+    # ensure scheme is a letter followed by letters, digits, and '+-.' chars
+    if not re.match(r'[a-z][-+.a-z0-9]*$', scheme, flags=re.I):
+        return ''
+    scheme = str(scheme)
+
+    # ensure domain and port are valid, eg: sub.domain.<1-to-6-TLD-chars>[:port]
+    match = re.match(r'(.+\.[a-z0-9]{1,6})(:\d{1,5})?$', netloc, flags=re.I)
+    if not match:
+        return ''
+    domain, port = match.groups()
+    netloc = domain + (port if port else '')
+    netloc = netloc.encode('idna')
+
+    # ensure path is valid and convert Unicode chars to %-encoded
+    if not path:
+        path = '/'  # eg: 'http://google.com' -> 'http://google.com/'
+    path = urllib.quote(urllib.unquote(path.encode('utf-8')), safe='/;')
+
+    # ensure query is valid
+    query = urllib.quote(urllib.unquote(query.encode('utf-8')), safe='=&?/')
+
+    # ensure fragment is valid
+    fragment = urllib.quote(urllib.unquote(fragment.encode('utf-8')))
+
+    # piece it all back together, truncating it to a maximum of 4KB
+    url = urlparse.urlunsplit((scheme, netloc, path, query, fragment))
+    return url[:4096]
 
 #http://diveintopython.org/http_web_services/etags.html
 class NotModifiedHandler(urllib2.BaseHandler):  
@@ -16,14 +71,18 @@
         return addinfourl
 
 def fetchURL(docsdb, url, fieldName, agencyID, scrape_again=True):
-    hash = hashlib.md5(url).hexdigest()
+    url = canonurl(url)
+    hash = hashlib.md5(url).hexdigest().encode("utf-8")
     req = urllib2.Request(url)
     print "Fetching %s" % url
+    if url.startswith("mailto") or url.startswith("javascript") or url.startswith("#") or url == None or url == "":
+		print "Not a valid HTTP url"
+		return (None,None)
     doc = docsdb.get(hash) 
     if doc == None:
 	doc = {'_id': hash, 'agencyID': agencyID, 'url': url, 'fieldName':fieldName}
     else:
-	if (time.time() - doc['page_scraped']) < 3600:
+	if (('page_scraped' in doc) and (time.time() - doc['page_scraped']) < 999999):
 		print "Uh oh, trying to scrape URL again too soon!"
 		last_attachment_fname = doc["_attachments"].keys()[-1]
 		last_attachment = docsdb.get_attachment(doc,last_attachment_fname)
@@ -41,17 +100,23 @@
         req.add_header("If-Modified-Since", doc['last_modified'])
      
     opener = urllib2.build_opener(NotModifiedHandler())
-    url_handle = opener.open(req)
-    headers = url_handle.info() # the addinfourls have the .info() too
-    doc['etag'] = headers.getheader("ETag")
-    doc['last_modified'] = headers.getheader("Last-Modified") 
-    doc['date'] = headers.getheader("Date") 
-    doc['page_scraped'] = time.time() 
-    doc['web_server'] = headers.getheader("Server") 
-    doc['powered_by'] = headers.getheader("X-Powered-By") 
-    doc['file_size'] = headers.getheader("Content-Length") 
-    doc['mime_type'] = headers.getheader("Content-Type").split(";")[0]
-    if hasattr(url_handle, 'code'): 
+    try:
+     url_handle = opener.open(req)
+     headers = url_handle.info() # the addinfourls have the .info() too
+     doc['etag'] = headers.getheader("ETag")
+     doc['last_modified'] = headers.getheader("Last-Modified") 
+     doc['date'] = headers.getheader("Date") 
+     doc['page_scraped'] = time.time() 
+     doc['web_server'] = headers.getheader("Server") 
+     doc['powered_by'] = headers.getheader("X-Powered-By") 
+     doc['file_size'] = headers.getheader("Content-Length") 
+     content_type = headers.getheader("Content-Type")
+     if content_type != None:
+    	doc['mime_type'] = content_type.split(";")[0]
+     else:
+	(type,encoding) = mimetypes.guess_type(url)
+	doc['mime_type'] = type
+     if hasattr(url_handle, 'code'): 
         if url_handle.code == 304:
             print "the web page has not been modified"
 	    return (None,None)
@@ -61,10 +126,15 @@
 	    doc = docsdb.get(hash) # need to get a _rev
 	    docsdb.put_attachment(doc, content, str(time.time())+"-"+os.path.basename(url), doc['mime_type']) 
 	    return (doc['mime_type'], content)
-    #store as attachment epoch-filename
-    else:
-        print "error %s in downloading %s" % url_handle.code, URL
-	doc['error'] = "error %s in downloading %s" % url_handle.code, URL    
+	    #store as attachment epoch-filename
+    except urllib2.URLError as e:
+    	error = ""
+	if hasattr(e, 'reason'):
+		error = "error %s in downloading %s" % (str(e.reason), url)
+	elif hasattr(e, 'code'):
+		error = "error %s in downloading %s" % (e.code, url)
+        print error
+	doc['error'] = error
         docsdb.save(doc)
         return (None,None)
 
@@ -92,6 +162,12 @@
 				# lets not do external links for now
 				# linkurls.add(link['href'])
 				None
+			if link['href'].startswith("mailto"):
+				# not http
+				None
+			if link['href'].startswith("javascript"):
+				# not http
+				None
 			else:
                 		linkurls.add(urljoin(url,link['href'].replace(" ","%20")))
             for linkurl in linkurls:
@@ -108,9 +184,15 @@
     agency = agencydb.get(row.id)
     print agency['name']
     for key in agency.keys():
-	if key == 'website' or key.endswith('URL'):
-		print key
-    		scrapeAndStore(docsdb, agency[key],agency['scrapeDepth'],key,agency['_id'])
-    agency['metadata']['lastscraped'] = time.time()
+	if key == 'website':
+    		scrapeAndStore(docsdb, agency[key],0,key,agency['_id'])
+	if key.endswith('URL'):
+		print key 
+		depth = 1
+		if 'scrapeDepth' in agency.keys():
+			depth = agency['scrapeDepth']
+   		scrapeAndStore(docsdb, agency[key],depth,key,agency['_id'])
+
+    agency['metadata']['lastScraped'] = time.time()
     agencydb.save(agency)