delete 'address' and add input validation

searches/quick_select.py

@@ -14,16 +14,21 @@ def _partition(data, pivot):
     """
     less, equal, greater = [], [], []
     for element in data:
-        if element.address < pivot.address:
+        if element < pivot:
             less.append(element)
-        elif element.address > pivot.address:
+        elif element > pivot:
             greater.append(element)
         else:
             equal.append(element)
     return less, equal, greater
 
 def quickSelect(list, k):
     #k = len(list) // 2 when trying to find the median (index that value would be when list is sorted)
+
+    #invalid input
+    if k>=len(list) or k<0:
+        return None
+
     smaller = []
     larger = []
     pivot = random.randint(0, len(list) - 1)
@@ -41,4 +46,4 @@ def quickSelect(list, k):
         return quickSelect(smaller, k)
     #must be in larger
     else:
-        return quickSelect(larger, k - (m + count))
+        return quickSelect(larger, k - (m + count))