Question 1 of 5
What does int | str mean when both operands are type objects?
Think “either listed type.”
A union combines the listed type alternatives; it does not convert values.
Review this lesson
Quiz
Back to lesson
Quick Check: Python Union Types with |
Test union expressions, None unions, normalization, supported runtime checks, and the runtime generic boundary.
5 questions
~6 min
Advanced
Knowledge check
Quick Check: Python Union Types with |
Test union expressions, None unions, normalization, supported runtime checks, and the runtime generic boundary.
- Stuck? Each question has an optional hint.
- Skip a hard question and review it before your results.
- Questions and answer options can shuffle between attempts.
You can retake this quiz whenever you like.
0:00
Question 2 of 5
What is str | None equivalent to?
None is one of the union members.
Optional[str] and str | None express the same type alternative. An argument having a default is a separate issue.
Review this lesson
Question 3 of 5
What is the result of (int | str | int) == (str | int)?
Compare the set of distinct type members.
Repeated members are removed for union equivalence, and ordering is ignored.
Review this lesson
Question 4 of 5
Which call tests whether a value is an instance of either listed type?
Use the built-in instance test for an object.
isinstance() accepts a union containing runtime-checkable type members.
Review this lesson
Question 5 of 5
Why is isinstance([], str | list[int]) invalid?
The limitation is the parameterized generic member.
The union syntax is supported, but parameterized generic aliases such as list[int] are not valid members for this runtime check.
Review this lesson
Quiz results
0/0
Review
-
What does int | str mean when both operands are type objects?Hint used
-
What is str | None equivalent to?Hint used
-
What is the result of (int | str | int) == (str | int)?Hint used
-
Which call tests whether a value is an instance of either listed type?Hint used
-
Why is isinstance([], str | list[int]) invalid?Hint used