Diamond problem in Python - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a class B that inherits from class A.

Python

class A:
    def greet(self):
        print("Hello from A")

class B([1]):
    pass

Drag options to blanks, or click blank then click option'

Aobject

BB

CA

DC

Attempts:

3 left

💡 Hint

Common Mistakes

Using the wrong class name in parentheses.

Forgetting to put parentheses after the class name.

Class B inherits from class A, so we write B(A).

2fill in blank

medium

Complete the code to call the greet method from class A inside class B.

Python

class A:
    def greet(self):
        print("Hello from A")

class B(A):
    def greet(self):
        [1].greet(self)
        print("Hello from B")

Drag options to blanks, or click blank then click option'

AA

Bsuper()

Cself

DB

Attempts:

3 left

💡 Hint

Common Mistakes

Using self.greet() which causes recursion.

Using super().greet() which is correct but not the answer here.

To call the greet method from class A, use A.greet(self).

3fill in blank

hard

Fix the error in the multiple inheritance class C that inherits from B and A.

Python

class A:
    def greet(self):
        print("Hello from A")

class B(A):
    def greet(self):
        print("Hello from B")

class C([1]):
    pass

Drag options to blanks, or click blank then click option'

AB, A

BA, B

CC, B

DB

Attempts:

3 left

💡 Hint

Common Mistakes

Reversing the order of inheritance.

Inheriting from only one class.

Class C inherits from B and A in that order to demonstrate the diamond problem: C(B, A).

4fill in blank

hard

Fill both blanks to complete the method in class C that calls greet using super().

Python

class C(B, A):
    def greet(self):
        [1]().greet()
        print("Hello from C")

Drag options to blanks, or click blank then click option'

Aself

Bsuper

CC

Dobject

Attempts:

3 left

💡 Hint

Common Mistakes

Using self.greet() which causes recursion.

Using class names instead of super().

Use super() to call the next method in the method resolution order.

5fill in blank

hard

Fill both blanks to create a dictionary comprehension that maps class names to their greet method outputs if the class is a subclass of A.

Python

classes = [A, B, C]
result = {({BLANK_2}}.__name__: [2]().greet() for [1] in classes if issubclass([2], A))

Drag options to blanks, or click blank then click option'

A{

Bcls

Attempts:

3 left

💡 Hint

Common Mistakes

Using list brackets instead of curly braces.

Using the wrong variable name.

Not calling greet on an instance.

This dictionary comprehension creates a dictionary where keys are class names and values are the result of calling greet on an instance of that class.