Fixed Inappropriate Logical Expression (TheAlgorithms#11203)

Signed-off-by: fazledyn-or <[email protected]>

Author: fazledyn-or

Diff for: data_structures/binary_tree/red_black_tree.py

@@ -451,7 +451,7 @@ def is_left(self) -> bool:
         """Returns true iff this node is the left child of its parent."""
         if self.parent is None:
             return False
-        return self.parent.left is self.parent.left is self
+        return self.parent.left is self
 
     def is_right(self) -> bool:
         """Returns true iff this node is the right child of its parent."""