From a5124253f1a81606ea96a24492911fb74b7711f6 Mon Sep 17 00:00:00 2001
From: Victor Schmidt <Vict0rSch@users.noreply.github.com>
Date: Mon, 8 Oct 2018 17:56:23 +0200
Subject: [PATCH 1/2] use set()

---
 snippets/difference.md | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/snippets/difference.md b/snippets/difference.md
index 949a26e75..0ae57c7c4 100644
--- a/snippets/difference.md
+++ b/snippets/difference.md
@@ -2,11 +2,12 @@
 
 Returns the difference between two iterables.
 
-Use list comprehension to only keep values not contained in `b`
+Use list comprehension to only keep values not contained in `b`. Use set to test `in` in `O(1)` time.
 
 ```python
 def difference(a, b):
-    return [item for item in a if item not in b]
+    _b = set(b)
+    return [item for item in a if item not in _b]
 ```
 ``` python
 difference([1, 2, 3], [1, 2, 4]) # [3]

From 2574fa0c6b2bd6ce85028222b46c24e693ab899a Mon Sep 17 00:00:00 2001
From: Angelos Chalaris <chalarangelo@gmail.com>
Date: Mon, 19 Aug 2019 14:02:59 +0300
Subject: [PATCH 2/2] Update difference.md

---
 snippets/difference.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/snippets/difference.md b/snippets/difference.md
index 0ae57c7c4..21d09c5c1 100644
--- a/snippets/difference.md
+++ b/snippets/difference.md
@@ -2,7 +2,7 @@
 
 Returns the difference between two iterables.
 
-Use list comprehension to only keep values not contained in `b`. Use set to test `in` in `O(1)` time.
+Use list comprehension to only keep values not contained in `b`.
 
 ```python
 def difference(a, b):