-1 if not in the list code example
Example: python checking not in list
a = [1, 2, 3, 4, 5, 6]
b = 7
c = 4
# use "not in" to check if something is not an element of a list
# use "in" to check if something is an element of a list
if b not in a:
print('True')
else:
print('False')
if c in a:
print('True')
else:
print('False')