[enh] add statistics answerer

searx/answerers/statistics/answerer.py

@@ -0,0 +1,51 @@
+from functools import reduce
+from operator import mul
+
+from flask_babel import gettext
+
+keywords = ('min',
+            'max',
+            'avg',
+            'sum',
+            'prod')
+
+
+# required answerer function
+# can return a list of results (any result type) for a given query
+def answer(query):
+    parts = query.query.split()
+
+    if len(parts) < 2:
+        return []
+
+    try:
+        args = map(float, parts[1:])
+    except:
+        return []
+
+    func = parts[0]
+    answer = None
+
+    if func == 'min':
+        answer = min(args)
+    elif func == 'max':
+        answer = max(args)
+    elif func == 'avg':
+        answer = sum(args)/len(args)
+    elif func == 'sum':
+        answer = sum(args)
+    elif func == 'prod':
+        answer = reduce(mul, args, 1)
+
+    if answer is None:
+        return []
+
+    return [{'answer': unicode(answer)}]
+
+
+# required answerer function
+# returns information about the answerer
+def self_info():
+    return {'name': gettext('Statistics functions'),
+            'description': gettext('Compute {functions} of the arguments').format(functions='/'.join(keywords)),
+            'examples': ['avg 123 548 2.04 24.2']}