REST APIs with Flask and Python - Mutable Default Parameters (and Why They're a Bad Idea)

The video tutorial discusses the pitfalls of using mutable default parameters in Python, using a student class example to illustrate the problem. It explains how mutable defaults can lead to unexpected behavior, such as shared state between instances. The tutorial provides a solution by using 'None' as a default and initializing the list within the function. It emphasizes best practices, advising against mutable defaults and suggesting alternatives like immutable types or initializing within the function.

What is a potential issue when using mutable default parameters in Python?

• They are not supported in Python 3.

• They make the code run slower.

• They can lead to unexpected behavior when shared across instances.

• They automatically convert to immutable types.

In the student class example, what happens when a new student is created without specifying grades?

• The new student gets a unique list of grades.

• The new student gets a random list of grades.

• The new student shares the same grades list with previous students.

• The new student cannot be created.

Why is it recommended to use 'None' as a default value for mutable parameters?

• It automatically converts to a string.

• It makes the code more readable.

• It ensures each instance gets a unique list.

• It prevents the function from being called.

What is a better way to handle type hints for optional parameters?

• Use 'Optional' from the typing module.

• Avoid using type hints altogether.

• Use a comment to explain the type.

• Use a string to describe the type.

Which of the following is NOT a recommended default parameter type?

• Boolean

• List

• String

• Integer