Use cases for each method type in Python - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Identify the use case of a static method

Which scenario best describes when to use a static method in a Python class?

A When the method needs to access or modify the class's attributes

B When the method performs a utility function that does not access instance or class data

C When the method is used to initialize a new instance of the class

D When the method needs to access or modify the instance's attributes

💡 Hint

Think about methods that don't need any information from the class or its objects.

A static method is used for utility functions that don't need to access instance or class data. It behaves like a regular function but lives inside the class for organization.

❓ Predict Output

intermediate

Output of a class method modifying class attribute

What is the output of this code?

Python

class Counter:
    count = 0

    @classmethod
    def increment(cls):
        cls.count += 1

Counter.increment()
Counter.increment()
print(Counter.count)

A 2

B 1

C 0

D Error

💡 Hint

Class methods can modify class-level data.

The class method increment increases the class attribute count by 1 each time it is called. After two calls, count becomes 2.

❓ Predict Output

intermediate

Output of instance method accessing instance data

What will this code print?

Python

class Person:
    def __init__(self, name):
        self.name = name

    def greet(self):
        return f"Hello, {self.name}!"

p = Person('Alice')
print(p.greet())

A Hello, !

B Hello, name!

C Hello, Alice!

D Error

💡 Hint

Instance methods use self to access data.

The instance method greet accesses the instance attribute name via self and returns a greeting with the actual name.

🧠 Conceptual

advanced

Choosing method type for factory pattern

Which method type is best suited to implement a factory method that creates instances of the class?

A Instance method

B Static method

C Property method

D Class method

💡 Hint

Factory methods often need to create instances and may need class information.

Class methods receive the class as the first argument and are commonly used as factory methods to create instances, possibly with different parameters or subclasses.

❓ Predict Output

expert

Output of mixed method calls in inheritance

What is the output of this code?

Python

class Base:
    @staticmethod
    def static_method():
        return 'Base static'

    @classmethod
    def class_method(cls):
        return f'{cls.__name__} class'

    def instance_method(self):
        return 'Base instance'

class Child(Base):
    @staticmethod
    def static_method():
        return 'Child static'

    @classmethod
    def class_method(cls):
        return f'{cls.__name__} class overridden'

    def instance_method(self):
        return 'Child instance'

c = Child()
print(c.static_method())
print(c.class_method())
print(c.instance_method())

A

Child static
Child class overridden
Child instance

B

Base static
Child class overridden
Base instance

C

Child static
Base class
Child instance

D

Base static
Base class
Base instance

💡 Hint

Look at which methods are overridden and how they are called.

The Child class overrides all three methods. Calling them on an instance of Child uses the overridden versions, so the output reflects the Child implementations.