Checking a List for a Value in Python

colors = ["red", "green", "blue"]

print("red" in colors)    # True
print("pink" in colors)   # False

if "pink" not in colors:
    print("No pink yet")

Full lesson:

Often you need to know if a list holds some value. Is this name on the guest list? Is this item in the cart?

x in my_list answers that. It compares each item with x, from the first one on. It gives True as soon as one matches, or False if none does.

Use x not in my_list for the opposite. It gives True when x is missing.

The answer is a bool, so it fits right into an if:

cart = ["milk", "bread"]

if "milk" in cart:
    print("Milk is in the cart")

It compares values, not indexes. So 2 in ["a", "b", "c"] is False, even though index 2 exists.

Text must match exactly. So "Red" in colors is False, because the list has "red".

Your task

bag holds what is packed for a hike.

If "water" is in bag, print Water is packed. If "tent" is not in bag, print Pack a tent.

Expected output:

Water is packed
Pack a tent