diff --git a/searx/engines/__init__.py b/searx/engines/__init__.py
index 358548247..b2750d0c2 100644
--- a/searx/engines/__init__.py
+++ b/searx/engines/__init__.py
@@ -163,7 +163,7 @@ def score_results(results):
                 duplicated = new_res
                 break
         if duplicated:
-            if len(res.get('content', '')) > len(duplicated.get('content', '')):  # noqa
+            if res.get('content') > duplicated.get('content'):
                 duplicated['content'] = res['content']
             duplicated['score'] += score
             duplicated['engines'].append(res['engine'])
diff --git a/searx/engines/json_engine.py b/searx/engines/json_engine.py
index e7cc808bb..708b999f8 100644
--- a/searx/engines/json_engine.py
+++ b/searx/engines/json_engine.py
@@ -39,7 +39,7 @@ def parse(query):
 
 def do_query(data, q):
     ret = []
-    if not len(q):
+    if not q:
         return ret
 
     qkey = q[0]
diff --git a/searx/engines/startpage.py b/searx/engines/startpage.py
index fcfc21160..cbafe0976 100644
--- a/searx/engines/startpage.py
+++ b/searx/engines/startpage.py
@@ -35,7 +35,7 @@ def response(resp):
         title = link.text_content()
 
         content = ''
-        if len(result.xpath('./p[@class="desc"]')):
+        if result.xpath('./p[@class="desc"]'):
             content = result.xpath('./p[@class="desc"]')[0].text_content()
 
         results.append({'url': url, 'title': title, 'content': content})
diff --git a/searx/engines/xpath.py b/searx/engines/xpath.py
index 04b021e33..9af24de3b 100644
--- a/searx/engines/xpath.py
+++ b/searx/engines/xpath.py
@@ -23,7 +23,7 @@ if xpath_results is a string element, then it's already done
 def extract_text(xpath_results):
     if type(xpath_results) == list:
         # it's list of result : concat everything using recursive call
-        if not len(xpath_results):
+        if not xpath_results:
             raise Exception('Empty url resultset')
         result = ''
         for e in xpath_results:
diff --git a/searx/engines/yacy.py b/searx/engines/yacy.py
index a4a41ac3b..efdf846ac 100644
--- a/searx/engines/yacy.py
+++ b/searx/engines/yacy.py
@@ -13,7 +13,7 @@ def request(query, params):
 def response(resp):
     raw_search_results = loads(resp.text)
 
-    if not len(raw_search_results):
+    if not raw_search_results:
         return []
 
     search_results = raw_search_results.get('channels', {})[0].get('items', [])
@@ -26,10 +26,10 @@ def response(resp):
         tmp_result['url'] = result['link']
         tmp_result['content'] = ''
 
-        if len(result['description']):
+        if result['description']:
             tmp_result['content'] += result['description'] + "<br/>"
 
-        if len(result['pubDate']):
+        if result['pubDate']:
             tmp_result['content'] += result['pubDate'] + "<br/>"
 
         if result['size'] != '-1':
diff --git a/searx/engines/youtube.py b/searx/engines/youtube.py
index 6e4e8859a..5b04f3513 100644
--- a/searx/engines/youtube.py
+++ b/searx/engines/youtube.py
@@ -22,9 +22,10 @@ def response(resp):
     if not 'feed' in search_results:
         return results
     feed = search_results['feed']
+
     for result in feed['entry']:
         url = [x['href'] for x in result['link'] if x['type'] == 'text/html']
-        if not len(url):
+        if not url:
             return
         # remove tracking
         url = url[0].replace('feature=youtube_gdata', '')
@@ -32,12 +33,13 @@ def response(resp):
             url = url[:-1]
         title = result['title']['$t']
         content = ''
-
         thumbnail = ''
-        if len(result['media$group']['media$thumbnail']):
+
+        if result['media$group']['media$thumbnail']:
             thumbnail = result['media$group']['media$thumbnail'][0]['url']
             content += '<a href="{0}" title="{0}" ><img src="{1}" /></a>'.format(url, thumbnail)  # noqa
-        if len(content):
+
+        if content:
             content += '<br />' + result['content']['$t']
         else:
             content = result['content']['$t']
diff --git a/searx/search.py b/searx/search.py
index f71adb2aa..7f991045b 100644
--- a/searx/search.py
+++ b/searx/search.py
@@ -49,7 +49,7 @@ class Search(object):
 
         self.categories = []
 
-        if len(self.engines):
+        if self.engines:
             self.categories = list(set(engine['category']
                                        for engine in self.engines))
         else:
@@ -59,13 +59,13 @@ class Search(object):
                     if not category in categories:
                         continue
                     self.categories.append(category)
-            if not len(self.categories):
+            if not self.categories:
                 cookie_categories = request.cookies.get('categories', '')
                 cookie_categories = cookie_categories.split(',')
                 for ccateg in cookie_categories:
                     if ccateg in categories:
                         self.categories.append(ccateg)
-            if not len(self.categories):
+            if not self.categories:
                 self.categories = ['general']
 
             for categ in self.categories:
diff --git a/searx/webapp.py b/searx/webapp.py
index 84d9c3f03..7477e1722 100644
--- a/searx/webapp.py
+++ b/searx/webapp.py
@@ -91,7 +91,7 @@ def render(template_name, **kwargs):
         for ccateg in cookie_categories:
             if ccateg in categories:
                 kwargs['selected_categories'].append(ccateg)
-        if not len(kwargs['selected_categories']):
+        if not kwargs['selected_categories']:
             kwargs['selected_categories'] = ['general']
     return render_template(template_name, **kwargs)
 
@@ -150,12 +150,12 @@ def index():
     elif search.request_data.get('format') == 'csv':
         csv = UnicodeWriter(cStringIO.StringIO())
         keys = ('title', 'url', 'content', 'host', 'engine', 'score')
-        if len(search.results):
+        if search.results:
             csv.writerow(keys)
             for row in search.results:
                 row['host'] = row['parsed_url'].netloc
                 csv.writerow([row.get(key, '') for key in keys])
-        csv.stream.seek(0)
+            csv.stream.seek(0)
         response = Response(csv.stream.read(), mimetype='application/csv')
         cont_disp = 'attachment;Filename=searx_-_{0}.csv'.format(search.query)
         response.headers.add('Content-Disposition', cont_disp)