fix deque __contains__

Author: cosminbasca

graalpython/lib-graalpython/_collections.py

@@ -304,18 +304,12 @@ def __repr__(self):
             maxlen_repr = ', maxlen=%d' % (self.maxlen,)
         return 'deque(%s%s)' % (list_repr, maxlen_repr)
 
-    def __compare__(self, w_other, op):
-        if not isinstance(w_other, deque):
+    def __compare__(self, other, op):
+        if not isinstance(other, deque):
             return NotImplemented
 
-        def _next_or_none(_iter):
-            try:
-                return next(_iter)
-            except StopIteration:
-                return None
-
         it1 = iter(self)
-        it2 = iter(w_other)
+        it2 = iter(other)
         while True:
             x1 = _next_or_none(it1)
             x2 = _next_or_none(it2)
@@ -349,6 +343,12 @@ def _next_or_none(_iter):
                     return x1 >= x2
                 assert False, "bad value for op"
 
+    def __contains__(self, item):
+        for itm in self:
+            if itm == item:
+                return True
+        return False
+
     def __lt__(self, other):
         return self.__compare__(other, 'lt')
 
@@ -438,6 +438,13 @@ def maxlen(self):
             return self._maxlen
 
 
+def _next_or_none(_iter):
+    try:
+        return next(_iter)
+    except StopIteration:
+        return None
+
+
 class _DequeIter(object):
     def __init__(self, dq):
         self._deque = dq