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Use isinstance() to check variable type - Python Program

The isinstance() function in Python is used to check if an object is an instance of a specified class or a subclass thereof. It returns True if the object is an instance of the class (or a subclass), and ;False otherwise.

# --- Example 1: Checking a single type --- variable_int = 10 variable_float = 3.14 variable_string = "hello" variable_list = [1, 2, 3] print(f"Is variable_int an integer? {isinstance(variable_int, int)}") print(f"Is variable_int a float? {isinstance(variable_int, float)}") print(f"\nIs variable_int a float? {isinstance(variable_float, float)}") print(f"Is variable_float an integer? {isinstance(variable_float, int)}") print(f"\nIs variable_string a string? {isinstance(variable_string, str)}") print(f"Is variable_list a list? {isinstance(variable_list, list)}") print(f"Is variable_int a string? {isinstance(variable_int, str)}") # --- Example 2: Checking against multiple types (using a tuple) --- variable_number = 5.5 variable_sequence = (4, 5, 6) print(f"\nIs variable_number an int or a float? {isinstance(variable_number, (int, float))}") print(f"Is variable_sequence a list or a tuple? {isinstance(variable_sequence, (list, tuple))}") # --- Example 3: Handling inheritance --- class Animal: pass class Dog(Animal): pass my_dog = Dog() my_animal = Animal() print(f"\nIs my_dog an instance of Dog? {isinstance(my_dog, Dog)}") print(f"Is my_dog an instance of Animal? {isinstance(my_dog, Animal)}") # True, due to inheritance print(f"Is my_animal an instance of Dog? {isinstance(my_animal, Dog)}")

Output

 
OUTPUT  :
Is variable_int an integer? True
Is variable_int a float? False

Is variable_int a float? True
Is variable_float an integer? False

Is variable_string a string? True
Is variable_list a list? True
Is variable_int a string? False

Is variable_number an int or a float? True
Is variable_sequence a list or a tuple? True

Is my_dog an instance of Dog? True
Is my_dog an instance of Animal? True
Is my_animal an instance of Dog? False