if variable not in list python code example

Example 1: Check if element in list Python

listA = [item1, item2, item3]
if item4 in listA:
  print('yes, item4 is in the list')
else:
  print('no, item4 is not in the list')

Example 2: python not in list

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

Example 3: python check if list contains value

if value in list:
  #do stuff

#Also to check if it doesn't contain
if value not in list:
  #do stuff