difference

snippets/difference.md

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+### difference
+
+Returns the difference between two arrays.
+
+Create a `set` from `b`, then use list comprehension to only keep values not contained in `b`
+
+```python 
+
+def difference(a, b):
+    b = set(b)
+    return [item for item in a if item not in b]
+
+```
+``` python
+difference([1, 2, 3], [1, 2, 4]) # [3]
+```