Creating boolean arrays in NumPy - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a boolean array where elements are True if they are greater than 5.

NumPy

import numpy as np
arr = np.array([3, 7, 2, 9, 5])
bool_arr = arr [1] 5

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

A==

B>

C<

D<=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '==' instead of '>' returns True only for elements equal to 5.

Using '<' or '<=' returns True for smaller or equal elements, not greater.

Using '>' compares each element to 5 and returns True if the element is greater than 5.

2fill in blank

medium

Complete the code to create a boolean array where elements are True if they are even numbers.

NumPy

import numpy as np
arr = np.array([1, 4, 7, 8, 10])
bool_arr = (arr [1] 2) == 0

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

A-

B+

C*

D%

Attempts:

3 left

💡 Hint

Common Mistakes

Using '+' or '-' instead of '%' does not check for even numbers.

Using '*' multiplies and does not help in checking evenness.

The modulus operator '%' gives the remainder. Even numbers have remainder 0 when divided by 2.

3fill in blank

hard

Fix the error in the code to create a boolean array where elements are True if less than or equal to 3.

NumPy

import numpy as np
arr = np.array([1, 4, 3, 2, 5])
bool_arr = arr [1] 3

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

A<

B=>

C<=

D==

Attempts:

3 left

💡 Hint

Common Mistakes

Using '=>' causes syntax errors.

Using '<' excludes elements equal to 3.

Using '==' only matches elements exactly equal to 3.

The correct operator for less than or equal is '<='. '=>' is invalid syntax.

4fill in blank

hard

Fill both blanks to create a boolean array where elements are True if they are between 3 and 7 inclusive.

NumPy

import numpy as np
arr = np.array([2, 3, 5, 7, 8])
bool_arr = (arr [1] 3) & (arr [2] 7)

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

A>=

B<

C<=

D>

Attempts:

3 left

💡 Hint

Common Mistakes

Using '>' or '<' excludes boundary values.

Using '|' instead of '&' changes logic to 'or' instead of 'and'.

To check if elements are between 3 and 7 inclusive, use '>=' for lower bound and '<=' for upper bound.

5fill in blank

hard

Fill all three blanks to create a dictionary with words as keys and boolean values indicating if word length is greater than 4.

NumPy

words = ['apple', 'bat', 'carrot', 'dog']
length_check = { [1]: len([2]) [3] 4 for [2] in words }

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

Aword

C>

Dlen(word)

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'len(word)' as key instead of 'word'.

Using '<' instead of '>' changes the condition.

Using different variable names for key and loop variable causes errors.

The dictionary comprehension uses 'word' as key, 'len(word) > 4' as condition, and iterates over 'word' in words.