Array Declaration and Initialization in DSA Python - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare an empty list named arr.

DSA Python

arr = [1]

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

A{}

B()

C[]

Darray()

Attempts:

3 left

💡 Hint

Common Mistakes

Using curly braces {} which creates a dictionary instead of a list.

Using parentheses () which creates a tuple instead of a list.

In Python, an empty list is declared using square brackets [].

2fill in blank

medium

Complete the code to create a list numbers with elements 1, 2, and 3.

DSA Python

numbers = [1]

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

A[1, 2, 3]

B(1, 2, 3)

C{1, 2, 3}

D1, 2, 3

Attempts:

3 left

💡 Hint

Common Mistakes

Using parentheses which creates a tuple, not a list.

Using curly braces which creates a set, not a list.

Lists with elements are created using square brackets with elements separated by commas.

3fill in blank

hard

Fix the error in the code to initialize a list letters with 'a', 'b', 'c'.

DSA Python

letters = [1]

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

A['a', 'b', 'c']

B('a', 'b', 'c')

C{'a', 'b', 'c'}

D'a', 'b', 'c'

Attempts:

3 left

💡 Hint

Common Mistakes

Using parentheses which creates a tuple instead of a list.

Using curly braces which creates a set instead of a list.

Lists use square brackets. Parentheses create tuples, curly braces create sets.

4fill in blank

hard

Fill both blanks to create a list evens with even numbers from 2 to 10.

DSA Python

evens = [[1] for [2] in range(2, 11, 2)]

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

Ax

Bi

Cx*2

Attempts:

3 left

💡 Hint

Common Mistakes

Using a variable in the output that is not defined in the loop.

Confusing the loop variable name.

The list comprehension uses i as both the output expression and loop variable since the range directly generates the even numbers.

5fill in blank

hard

Fill all three blanks to create a list squares of squares of numbers from 1 to 5.

DSA Python

squares = [[1] for [2] in [3](1, 6)]

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

Anum**2

Bnum

Crange

Dsquare

Attempts:

3 left

💡 Hint

Common Mistakes

Using a function other than range for iteration.

Using a variable name not consistent in output and loop.

The list comprehension squares each number num in the range from 1 to 5.