not contains in python in array code example

Example 1: python check string not exist in array

arr_test = ["thetung1","thetung2","thetung3"]
title = "thetung"
if title not in arr_test:
	arr_test.append(title)

Example 2: python not in list

>>> 3 not in [2, 3, 4]
False
>>> 3 not in [4, 5, 6]
True