in — Easy Playground

Membership test operator; also used in for loops to iterate over items

Python Playground

# in with lists
fruits = ["apple", "banana", "cherry"]
print("banana" in fruits)
print("grape" in fruits)

# in with strings
text = "Hello, World!"
print("World" in text)
print("xyz" in text)

# in with dictionaries (checks keys)
ages = {"Alice": 30, "Bob": 25}
print("Alice" in ages)
print(30 in ages)  # checks keys, not values

Output

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'in' tests membership. For lists it checks values, for strings it checks substrings, for dicts it checks keys.

Challenge

Try modifying the code above to explore different behaviors. Can you extend the example to handle a new use case?

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