Data Science with Python Certification Introduction to Python for Data Science 2

Question 1

Which Python data type is immutable and can be used as a dictionary key?

Accepted Answer

tuple

Answer

Tuples are immutable sequences and can be used as dictionary keys, unlike lists or sets.

Question 2

What does the `zip()` function return when passed two lists of unequal length?

Accepted Answer

Stops at the length of the shorter list

Answer

`zip()` stops producing tuples when the shortest input iterable is exhausted.

Question 3

Which method removes and returns the last element of a Python list?

Accepted Answer

list.pop()

Answer

`list.pop()` removes and returns the last element by default, or an element at a given index.

Question 4

What is the result of `bool([])` in Python?

Accepted Answer

False

Answer

An empty list is falsy in Python, so `bool([])` evaluates to `False`.

Question 5

Which of the following correctly creates a dictionary using a dictionary comprehension?

Accepted Answer

{x: x**2 for x in range(5)}

Answer

Dictionary comprehensions use curly braces with a `key: value` expression followed by a `for` clause.

Data Science with Python Certification Practice Test