in keyword with sets in Python

in / not in Keyword in Python The in keyword is used to check whether an element exists in a set (or any iterable such as a list, tuple, or string).

Syntax

element in set_name
element not in set_name

Return Value

• Returns True → if the element exists in the set.
• Returns False → if the element does not exist in the set.

Example: Basic Usage

Python

# Define a set
fruits = {"apple", "banana", "cherry"}

print("apple" in fruits)       # True
print("grape" in fruits)       # False
print("banana" not in fruits)  # False

Explanation

• "apple" exists in the set → True
• "grape" does not exist in the set → False
• "banana" not in fruits → False because "banana" is present

Example: Using in Inside if Statement

Python

# Define a set
colors = {"red", "green", "blue"}

if "green" in colors:
    print("Green is available!")
else:
    print("Green is not available.")

Output Green is available!

Example: Case Sensitivity

Python

# Define a set
animals = {"Cat", "Dog", "Elephant"}

print("cat" in animals)  # False
print("Cat" in animals)  # True

Note: Sets are case-sensitive, just like strings. "Cat" and "cat" are treated as different values.