Remove unnecessary code in wolframalpha_noapi engine

The answer is scraped from a js function, so parsing the html tree
doesn't achieve anything here.

searx/engines/wolframalpha_noapi.py

@@ -10,8 +10,6 @@
 import re
 import json
 from urllib import urlencode
-from lxml import html
-from searx.engines.xpath import extract_text
 
 # search-url
 url = 'http://www.wolframalpha.com/'
@@ -25,42 +23,31 @@ def request(query, params):
     return params
 
 
-# tries to find answer under the pattern given
-def extract_answer(script_list, pattern):
-    answer = None
+# get response from search-request
+def response(resp):
+    results = []
+    
+    # the answer is inside a js function
+    # answer can be located in different 'pods', although by default it should be in pod_0200
+    possible_locations = ['pod_0200\.push(.*)\n',
+                          'pod_0100\.push(.*)\n']
 
     # get line that matches the pattern
-    for script in script_list:
+    for pattern in possible_locations:
         try:
-            line = re.search(pattern, script.text_content()).group(1)
+            line = re.search(pattern, resp.text).group(1)
+            break
         except AttributeError:
             continue
 
-        # extract answer from json
-        answer = line[line.find('{') : line.rfind('}')+1]
-        answer = json.loads(answer.encode('unicode-escape'))
-        answer = answer['stringified'].decode('unicode-escape')
+    if not line:
+        return results
 
-    return answer
+    # extract answer from json
+    answer = line[line.find('{') : line.rfind('}')+1]
+    answer = json.loads(answer.encode('unicode-escape'))
+    answer = answer['stringified'].decode('unicode-escape')
 
-
-# get response from search-request
-def response(resp):
-
-    dom = html.fromstring(resp.text)
-
-    # the answer is inside a js script
-    scripts = dom.xpath('//script')
-
-    results = []
-
-    # answer can be located in different 'pods', although by default it should be in pod_0200
-    answer = extract_answer(scripts, 'pod_0200\.push(.*)\n')
-    if not answer:
-        answer = extract_answer(scripts, 'pod_0100\.push(.*)\n')
-        if answer:
-            results.append({'answer': answer})
-    else:
-        results.append({'answer': answer})
+    results.append({'answer': answer})
     
     return results