Membership and identity

Learn in and is operators.

Membership and identity operators

The in operator checks whether a value is in a collection. is checks whether two variables point to the same object.

print(3 in [1, 2, 3])      # True
print("a" in "ali")         # True
print(a is None)            # None check

in works with lists, strings, tuples and dicts. is is for identity; for value equality use ==.

is checks whether two variables point to the same object (identity). == checks whether the values are equal.

a = [1, 2]
b = [1, 2]
print(a == b)   # True (same value)
print(a is b)   # False (different object)

a and b have the same value but are different objects. So == is True, is is False. Using is None is the right way to check None.

Assign numbers = [1, 2, 3, 4]. Print print(3 in numbers) and print(5 in numbers).

Show example solution

numbers = [1, 2, 3, 4]
print(3 in numbers)
print(5 in numbers)

Membership check

print(3 ____ [1, 2, 3])

Show answer

print(3 in [1, 2, 3])