In [1]:
if 1 in [1,2,3]:
    print('List')

if 4 not in {1,2,3}:
    print('Tuple')

if 'apple' in 'pineapple':
    print('String')
List
Tuple
String
In [2]:
print(1 in [1,2,3])
print(4 in {1,2,3})
print('day' in 'today')
True
False
True