Travis build: 910

test/count_by/count_by.py

@@ -1,6 +1,6 @@
 def count_by(arr, fn=lambda x: x):
     key = {}
     for el in map(fn, arr):
-        key[el] = 0 if not el in key else key[el]
+        key[el] = 0 if el not in key else key[el]
         key[el] += 1
     return key